Science.gov

Sample records for alkyl aryl sulfonates

  1. Palladium-catalyzed direct α-arylation of methyl sulfones with aryl bromides.

    PubMed

    Zheng, Bing; Jia, Tiezheng; Walsh, Patrick J

    2013-04-01

    A direct and efficient approach for palladium-catalyzed arylation of aryl and alkyl methyl sulfones with aryl bromides has been developed. The catalytic system affords arylated sulfones in good to excellent yields (73-90%). PMID:23517309

  2. Iron-Catalyzed Cross-Coupling of Unactivated, Secondary Alkyl Thio Ethers and Sulfones with Aryl Grignard Reagents

    PubMed Central

    Denmark, Scott E.; Cresswell, Alexander J.

    2013-01-01

    The first systematic investigation of unactivated aliphatic sulfur compounds as electrophiles in transition metal-catalyzed cross-coupling are described. Initial studies focused on discerning the structural and electronic features of the organosulfur substrate which enable the challenging oxidative addition to the C(sp3)–S bond. Through extensive optimization efforts, an Fe(acac)3-catalyzed cross-coupling of unactivated alkyl aryl thio ethers with aryl Grignard reagents was realized, in which a nitrogen “directing group” on the S-aryl moiety of the thio ether served a critical role in facilitating the oxidative addition step. In addition, alkyl phenyl sulfones were found to be effective electrophiles in the Fe(acac)3-catalyzed cross-coupling with aryl Grignard reagents. For the latter class of electrophile, a thorough assessment of the various reaction parameters revealed a dramatic enhancement in reaction efficiency with an excess of TMEDA (8.0 equiv). The optimized reaction protocol was used to evaluate the scope of the method with respect to both the organomagnesium nucleophile and sulfone electrophile. PMID:24256193

  3. Stereoconvergent Arylations and Alkenylations of Unactivated Alkyl Electrophiles: Catalytic Enantioselective Synthesis of Secondary Sulfonamides and Sulfones

    PubMed Central

    2015-01-01

    The development of efficient methods for the generation of enantioenriched sulfonamides and sulfones is an important objective for fields such as organic synthesis and medicinal chemistry; however, there have been relatively few reports of direct catalytic asymmetric approaches to controlling the stereochemistry of the sulfur-bearing carbon of such targets. In this report, we describe nickel-catalyzed stereoconvergent Negishi arylations and alkenylations of racemic α-bromosulfonamides and -sulfones that furnish the desired cross-coupling product in very good ee and yield for an array of reaction partners. Mechanistic studies are consistent with the generation of a radical intermediate that has a sufficient lifetime to diffuse out of the solvent cage and to cyclize onto a pendant olefin. PMID:25127186

  4. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  5. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  6. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  7. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  8. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  9. Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

    1992-01-01

    Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

  10. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aryl sulfonate of a fatty acid mixture... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  11. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Aryl sulfonate of a fatty acid mixture... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  12. Alkyl Aryl Ether Bond Formation with PhenoFluor**

    PubMed Central

    Shen, Xiao; Neumann, Constanze N.; Kleinlein, Claudia; Claudia, Nathaniel W.; Ritter, Tobias

    2015-01-01

    An alkyl aryl ether bond formation reaction between phenols and primary and secondary alcohols with PhenoFluor has been developed. The reaction features a broad substrate scope and tolerates many functional groups, and substrates that are challenging for more conventional ether bond forming processes may be coupled. A preliminary mechanistic study indicates reactivity distinct from conventional ether bond formation. PMID:25800679

  13. 40 CFR 721.10437 - Sulfonic acid, linear xylene alkylate, mono, sodium salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sulfonic acid, linear xylene alkylate... Significant New Uses for Specific Chemical Substances § 721.10437 Sulfonic acid, linear xylene alkylate, mono... chemical substances identified generically as sulfonic acid, linear xylene alkylate, mono, sodium...

  14. 40 CFR 721.10437 - Sulfonic acid, linear xylene alkylate, mono, sodium salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Sulfonic acid, linear xylene alkylate... Significant New Uses for Specific Chemical Substances § 721.10437 Sulfonic acid, linear xylene alkylate, mono... chemical substances identified generically as sulfonic acid, linear xylene alkylate, mono, sodium...

  15. 40 CFR 721.644 - Amines, C12-14-tert-alkyl, sulfonates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amines, C12-14-tert-alkyl, sulfonates... Substances § 721.644 Amines, C12-14-tert-alkyl, sulfonates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amines, C12-14-tert-alkyl, sulfonates...

  16. 40 CFR 721.2565 - Alkylated sulfonated diphenyl oxide, alkali and amine salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylated sulfonated diphenyl oxide... New Uses for Specific Chemical Substances § 721.2565 Alkylated sulfonated diphenyl oxide, alkali and... substances identified as alkylated sulfonated diphenyl oxide, alkali salt (PMN P-93-352) and...

  17. 40 CFR 721.644 - Amines, C12-14-tert-alkyl, sulfonates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amines, C12-14-tert-alkyl, sulfonates... Substances § 721.644 Amines, C12-14-tert-alkyl, sulfonates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amines, C12-14-tert-alkyl, sulfonates...

  18. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., polyamine condensate. 721.6220 Section 721.6220 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  19. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., polyamine condensate. 721.6220 Section 721.6220 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  20. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., polyamine condensate. 721.6220 Section 721.6220 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  1. Aryl sulfonates as neutral photoacid generators (PAGs) for EUV lithography

    NASA Astrophysics Data System (ADS)

    Sulc, Robert; Blackwell, James M.; Younkin, Todd R.; Putna, E. Steve; Esswein, Katherine; DiPasquale, Antonio G.; Callahan, Ryan; Tsubaki, Hideaki; Tsuchihashi, Tooru

    2009-03-01

    EUV lithography (EUVL) is a leading candidate for printing sub-32 nm hp patterns. In order for EUVL to be commercially viable at these dimensions, a continuous evolution of the photoresist material set is required to simultaneously meet the aggressive specifications for resolution, resist sensitivity, LWR, and outgassing rate. Alternative PAG designs, especially if tailored for EUVL, may aid in the formation of a material set that helps achieve these aggressive targets. We describe the preparation, characterization, and lithographic evaluation of aryl sulfonates as non-ionic or neutral photoacid generators (PAGs) for EUVL. Full lithographic characterization is reported for our first generation resist formulation using compound H, MAP-1H-2.5. It is benchmarked against MAP-1P-5.0, which contains the well-known sulfonium PAG, triphenylsulfonium triflate (compound P). Z-factor analysis indicates nZ32 = 81.4 and 16.8 respectively, indicating that our first generation aryl sulfonate formulations require about 4.8x improvement to match the results achieved with a model onium PAG. Improving the acid generation efficiency and use of the generated byproducts is key to the continued optimization of this class of PAGs. To that end, we believe EI-MS fragmentation patterns and molecular simulations can be used to understand and optimize the nature and efficiency of electron-induced PAG fragmentation.

  2. Modular synthesis of triarylmethanes through palladium-catalyzed sequential arylation of methyl phenyl sulfone.

    PubMed

    Nambo, Masakazu; Crudden, Cathleen M

    2014-01-13

    Triarylmethanes, which are valuable structures in materials, sensing and pharmaceuticals, have been synthesized starting from methyl phenyl sulfone as an inexpensive and readily available template. The three aryl groups were installed through two sequential palladium-catalyzed C-H arylation reactions, followed by an arylative desulfonation. This method provides a new synthetic approach to multisubstituted triarylmethanes using readily available haloarenes and aryl boronic acids, and is also valuable for the preparation of unexplored triarylmethane-based materials and pharmaceuticals. PMID:24307286

  3. 40 CFR 721.950 - Sodium salt of an alkylated, sulfonated aromatic (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., sulfonated aromatic (generic name). 721.950 Section 721.950 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.950 Sodium salt of an alkylated, sulfonated... chemical substance identified generically as a sodium salt of an alkylated, sulfonated aromatic (PMN...

  4. 40 CFR 721.950 - Sodium salt of an alkylated, sulfonated aromatic (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sodium salt of an alkylated... Significant New Uses for Specific Chemical Substances § 721.950 Sodium salt of an alkylated, sulfonated... chemical substance identified generically as a sodium salt of an alkylated, sulfonated aromatic (PMN...

  5. Synthesis Of [2h, 13c]M [2h2m 13c], And [2h3,, 13c] Methyl Aryl Sulfones And Sulfoxides

    DOEpatents

    Martinez, Rodolfo A.; Alvarez, Marc A.; Silks, III, Louis A.; Unkefer, Clifford J.; Schmidt, Jurgen G.

    2004-07-20

    The present invention is directed to labeled compounds, [.sup.2 H.sub.1, .sup.13 C], [.sup.2 H.sub.2, .sup.13 C] and [.sup.2 H.sub.3, .sup.13 C]methyl aryl sulfones and [.sup.2 H.sub.1, .sup.13 C], [.sup.2 H.sub.2, .sup.13 C] and [.sup.2 H.sub.3, .sup.13 C]methyl aryl sulfoxides, wherein the .sup.13 C methyl group attached to the sulfur of the sulfone or sulfoxide includes exactly one, two or three deuterium atoms and the aryl group is selected from the group consisting of 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, and phenyl groups with the structure: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently, hydrogen, a C.sub.1 -C.sub.4 lower alkyl, a halogen, an amino group from the group consisting of NH.sub.2, NHR and NRR' where R and R' are each a C.sub.1 -C.sub.4 lower alkyl, a phenyl, or an alkoxy group. The present invention is also directed to processes of preparing methyl aryl sulfones and methyl aryl sulfoxides.

  6. Copper-catalyzed aerobic oxidation and cleavage/formation of C-S bond: a novel synthesis of aryl methyl sulfones from aryl halides and DMSO.

    PubMed

    Yuan, Gaoqing; Zheng, Junhua; Gao, Xiaofang; Li, Xianwei; Huang, Liangbin; Chen, Huoji; Jiang, Huanfeng

    2012-08-01

    With atmospheric oxygen as the oxidant, a novel copper(I)-catalyzed synthesis of aryl methyl sulfones from aryl halides and widely available DMSO is described. The procedure tolerates aryl halides with various functional groups (such as methoxy, acetyl, chloro, fluoro and nitro groups), which could afford aryl methyl sulfones in moderate to high yields. The copper-catalyzed aerobic oxidation and the cleavage/formation of C-S bond are the key steps for this transformation. PMID:22728918

  7. Synthesis of tricyclic heterocycles via a tandem aryl alkylation/heck coupling sequence.

    PubMed

    Alberico, Dino; Rudolph, Alena; Lautens, Mark

    2007-02-01

    A norbornene-mediated palladium-catalyzed sequence is described in which two alkyl-aryl bonds and one alkenyl-aryl bond are formed in one pot with use of microwave irradiation. A variety of symmetrical and unsymmetrical oxygen-, nitrogen-, silicon-, and sulfur-containing tricyclic heterocycles were synthesized from a Heck acceptor and an aryl iodide containing two tethered alkyl halides. This approach was further applied to the synthesis of a tricyclic mescaline analogue. PMID:17253794

  8. Palladium-Catalyzed Heteroarylation and Concomitant ortho-Alkylation of Aryl Iodides.

    PubMed

    Lei, Chuanhu; Jin, Xiaojia; Zhou, Jianrong Steve

    2015-11-01

    Three-component couplings were achieved from common aryl halides, alkyl halides, and heteroarenes under palladium and norbornene co-catalysis. The reaction forges hindered aryl-heteroaryl bonds and introduces ortho-alkyl groups to aryl rings. Various heterocycles such as oxazoles, thiazoles and thiophenes underwent efficient coupling. The heteroarenes were deprotonated in situ by bases without the assistance of palladium catalysts. PMID:26358935

  9. Accessing 2,1-Borazaronaphthols: Self-Arylation of 1-Alkyl-2-aryl-3-bromo-2,1-borazaronaphthalenes

    PubMed Central

    2015-01-01

    Unlike their B-alkyl counterparts, brominated N-alkyl B-aryl 2,1-borazaronaphthalenes undergo a self-arylation reaction in the presence of a catalytic amount of palladium and base, in which the azaborine serves as both the electrophile and the nucleophile. The products of the self-arylation are air- and moisture-stable 2,1-borazaronaphthols, previously only observed in basic alcoholic solvents. The steric encumbrance of the azaborine appears to prevent formation of the corresponding boron acid anhydride, allowing access to a family of 2,1-borazaronaphthol derivatives. PMID:25133658

  10. 40 CFR 721.2565 - Alkylated sulfonated diphenyl oxide, alkali and amine salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... substances identified as alkylated sulfonated diphenyl oxide, alkali salt (PMN P-93-352) and alkylated sulfonated diphenyl oxide, amine salt (PMN P-93-353) are subject to reporting under this section for the...) Release to water. Requirements as specified in § 721.90 (a)(4), (b)(4), and (c)(4) (where N = 20 ppb)....

  11. 2-Alkyl-4-aryl-pyrimidine fused heterocycles as selective 5-HT2A antagonists.

    PubMed

    Shireman, Brock T; Dvorak, Curt A; Rudolph, Dale A; Bonaventure, Pascal; Nepomuceno, Diane; Dvorak, Lisa; Miller, Kirsten L; Lovenberg, Timothy W; Carruthers, Nicholas I

    2008-03-15

    The synthesis and SAR for a novel series of 2-alkyl-4-aryl-tetrahydro-pyrido-pyrimidines and 2-alkyl-4-aryl-tetrahydro-pyrimido-azepines is described. Representative compounds were shown to be subtype selective 5-HT(2A) antagonists. Optimal placement of a basic nitrogen relative to the pyrimidine and the presence of a 4-fluorophenyl group in the pyrimidine 4-position was found to have a profound effect on affinity and selectivity. PMID:18282705

  12. 40 CFR 721.9597 - Salt of a substituted sulfonated aryl azo compound (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... azo compound (generic). 721.9597 Section 721.9597 Protection of Environment ENVIRONMENTAL PROTECTION... compound (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as salt of a substituted sulfonated aryl azo compound (PMN P-00-0094)...

  13. 40 CFR 721.9597 - Salt of a substituted sulfonated aryl azo compound (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... azo compound (generic). 721.9597 Section 721.9597 Protection of Environment ENVIRONMENTAL PROTECTION... compound (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as salt of a substituted sulfonated aryl azo compound (PMN P-00-0094)...

  14. 40 CFR 721.9597 - Salt of a substituted sulfonated aryl azo compound (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... azo compound (generic). 721.9597 Section 721.9597 Protection of Environment ENVIRONMENTAL PROTECTION... compound (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as salt of a substituted sulfonated aryl azo compound (PMN P-00-0094)...

  15. 40 CFR 721.9597 - Salt of a substituted sulfonated aryl azo compound (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... azo compound (generic). 721.9597 Section 721.9597 Protection of Environment ENVIRONMENTAL PROTECTION... compound (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as salt of a substituted sulfonated aryl azo compound (PMN P-00-0094)...

  16. 40 CFR 721.9597 - Salt of a substituted sulfonated aryl azo compound (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... azo compound (generic). 721.9597 Section 721.9597 Protection of Environment ENVIRONMENTAL PROTECTION... compound (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as salt of a substituted sulfonated aryl azo compound (PMN P-00-0094)...

  17. DETERMINATION OF ALKYLATED & SULFONATED DIPHENYL OXIDE SULFACTANT BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

    EPA Science Inventory

    Methods for the determination of the anionic surfactant Dowfax 8390 are described. Dowfax is a complex mixture of various alkylated and sulfonated diphenyl oxides. The primary component of Dowfax is monoalkylated disulfonated diphenyl oxide (MADS). This work uses ion pairing chro...

  18. Copper-catalyzed arylation of alkyl halides with arylaluminum reagents

    PubMed Central

    Shrestha, Bijay

    2015-01-01

    Summary We report a Cu-catalyzed coupling between triarylaluminum reagents and alkyl halides to form arylalkanes. The reaction proceeds in the presence of N,N,N’,N’-tetramethyl-o-phenylenediamine (NN-1) as a ligand in combination with CuI as a catalyst. This catalyst system enables the coupling of primary alkyl iodides and bromides with electron-neutral and electron-rich triarylaluminum reagents and affords the cross-coupled products in good to excellent yields. PMID:26734088

  19. Copper-catalyzed arylation of alkyl halides with arylaluminum reagents.

    PubMed

    Shrestha, Bijay; Giri, Ramesh

    2015-01-01

    We report a Cu-catalyzed coupling between triarylaluminum reagents and alkyl halides to form arylalkanes. The reaction proceeds in the presence of N,N,N',N'-tetramethyl-o-phenylenediamine (NN-1) as a ligand in combination with CuI as a catalyst. This catalyst system enables the coupling of primary alkyl iodides and bromides with electron-neutral and electron-rich triarylaluminum reagents and affords the cross-coupled products in good to excellent yields. PMID:26734088

  20. Promotion of Organic Reactions by Ultrasound: Coupling of Alkyl and Aryl Halides in the Presence of Lithium Metal and Ultrasound.

    ERIC Educational Resources Information Center

    Lash, Timothy D.; Berry, Donna

    1985-01-01

    Experiments involving the coupling of alkyl and aryl halides in the presence of lithium metal and ultrasound are described. The experiments illustrate classical Wurtz and Fittig reactions in addition to being a convenient application of organic sonochemistry. (JN)

  1. A sulfonated poly (aryl ether ether ketone ketone) isomer: synthesis and DMFC performance

    SciTech Connect

    Kim, Yu Seung; Liu, Baijun; Hu, Wei; Jiang, Zhenhua; Robertson, Gilles; Guiver, Michael

    2009-01-01

    A sulfonated poly(aryl ether ether ketone ketone) (PEEKK) having a well-defined rigid homopolymer-like chemical structure was synthesized from a readily-prepared PEEKK post-sulfonation with concentrated sulfuric acid at room temperature within several hours. The polymer electrolyte membrane (PEM) cast from the resulting polymer exhibited an excellent combination of thermal resistance, oxidative and dimensional stability, low methanol fuel permeability and high proton conductivity. Furthermore, membrane electrode assemblies (MEAs) were successfully fabricated and good direct methanol fuel cell (DMFC) performance was observed. At 2 M MeOH feed, the current density at 0.5 V reached 165 mA/cm, which outperformed our reported analogues and eveluated Nafion membranes.

  2. Practical Ni-Catalyzed Aryl-Alkyl Cross-Coupling of Secondary Redox-Active Esters.

    PubMed

    Cornella, Josep; Edwards, Jacob T; Qin, Tian; Kawamura, Shuhei; Wang, Jie; Pan, Chung-Mao; Gianatassio, Ryan; Schmidt, Michael; Eastgate, Martin D; Baran, Phil S

    2016-02-24

    A new transformation is presented that enables chemists to couple simple alkyl carboxylic acids with aryl zinc reagents under Ni-catalysis. The success of this reaction hinges on the unique use of redox-active esters that allow one to employ such derivatives as alkyl halides surrogates. The chemistry exhibits broad substrate scope and features a high degree of practicality. The simple procedure and extremely inexpensive nature of both the substrates and pre-catalyst (NiCl2·6H2O, ca. $9.5/mol) bode well for the immediate widespread adoption of this method. PMID:26835704

  3. Copper-catalyzed trifluoromethylselenolation of aryl and alkyl halides: the silver effect in transmetalation.

    PubMed

    Chen, Chaohuang; Hou, Chuanqi; Wang, Yuguang; Hor, T S Andy; Weng, Zhiqiang

    2014-01-17

    A catalytic trifluoromethylselenolation of aryl and alkyl halides by a Cu(I) catalyst has been developed. A key intermediate, [(phen)Cu(SeCF3)]2 (5) was successfully isolated and characterized by X-ray diffraction. The important role of silver in the transmetalation process during the catalytic cycle was elucidated. A wide range of trifluoromethylselanes have been prepared from readily available starting materials from a method that tolerates various important functional groups. PMID:24372349

  4. Interfacial assignment of branched-alkyl benzene sulfonates: A molecular simulation

    NASA Astrophysics Data System (ADS)

    Liu, Zi-Yu; Wei, Ning; Wang, Ce; Zhou, He; Zhang, Lei; Liao, Qi; Zhang, Lu

    2015-11-01

    A molecular dynamics simulation was conducted to analyze orientations of sodium branched-alkyl benzene sulfonates molecules at nonane/water interface, which is helpful to design optimal surfactant structures to achieve ultralow interfacial tension (IFT). Through the two dimensional density profiles, monolayer collapses are found when surfactant concentration continues to increase. Thus the precise scope of monolayer is certain and orientation can be analyzed. Based on the simulated results, we verdict the interfacial assignment of branched-alkyl benzene sulfonates at the oil-water interface, and discuss the effect of hydrophobic tail structure on surfactant assignment. Bigger hydrophobic size can slow the change rate of surfactant occupied area as steric hindrance, and surfactant meta hydrophobic tails have a stronger tendency to stretch to the oil phase below the collapsed concentration. Furthermore, an interfacial model with reference to collapse, increasing steric hindrance and charge repulsive force between interfacial surfactant molecules, responsible for effecting of surfactant concentration and structure has been supposed.

  5. Pathomorphological changes in gills of fish fingerlings (Cirrhina mrigala) by linear alkyl benzene sulfonate

    SciTech Connect

    Misra, V.; Lal, H.; Chawla, G.; Viswanathan, P.N.

    1985-12-01

    Fish fingerlings (Cirrhina mrigala) exposed to 0.005 ppm (25% of LC50) concentration to detergents (linear alkyl benzene sulfonate) showed marked behavioral changes and distorted appearance of primary and secondary lamellae along with damage to gill epithelium under scanning electron microscopy at various magnifications. Mucosal cells of gills were found to secrete mucus showing primary reactions for membrane damage leading to dysfunction in respiration and osmoregulation.

  6. Acute toxicity to goldfish of mixtures of chloramines, copper, and linear alkylate sulfonate

    SciTech Connect

    Tsai, C.F.; McKee, J.A.

    1980-01-01

    The toxicity to goldfish (Carassius auratus) of mixtures of chloramines, copper, and linear alkylate sulfonate (LAS) was studied by continuous-flow toxicity tests during an exposure period of 96 hours. The individual toxicities of these three chemicals are either additive or synergistic in mixtures, depending on the rate of toxic action of the individual chemical, the toxicity ratio of the chemicals in the mixtures, and the concentration of the mixtures.

  7. Stereochemical evaluation of bis(phosphine) copper catalysts for the asymmetric alkylation of 3-bromooxindoles with α-arylated malonate esters

    PubMed Central

    Lee, Chung Whan; Han, Seo-Jung; Virgil, Scott C.; Stoltz, Brian M.

    2014-01-01

    An improved method for the asymetric alkylation of 3-bromooxindoles with α-arylated malonate esters is described. The asymmetric alkylation demonstrated was achieved up to 70% ee utilizing a copper(II) bis(phosphine) complex. PMID:25983348

  8. Structure-Activity Relationship Studies of Gonadotropin Releasing Hormone Antagonists Containing S-aryl/alkyl Norcysteines and their Oxidized Derivatives

    PubMed Central

    Samant, Manoj P.; White, Richard; Hong, Doley J.; Croston, Glenn; Conn, P. Michael; Janovick, Jo Ann; Rivier, Jean

    2008-01-01

    A series of acyline analogues incorporating l- and d- isomers of S-arylated/alkylated norcysteines [Ncy(R), where R is 2-naphthyl, methyl and isopropyl] at positions 1, 4, 7 and 10 were synthesized. Some of these analogues were mono- and di-oxidized to sulfoxides and sulfones. All of the analogues of acyline were screened for the antagonism of GnRH-induced response in a reporter gene assay in HEK-293 cells expressing the human GnRH receptor. Nine of the analogues (9, 11, 15, 16, 17, 19, 20, 21, and 22) had an antagonist potency (IC50 < 2 nM) similar to that of acyline (IC50 = 0.52 nM) in this assay. Selected analogues (9, 11, 15, 16, 19 and 21) were tested in vitro for their antagonism at the rat GnRH-R in a reporter gene assay as well as in an in vivo intact male rat assay. Analogues 9 and 15 were most potent in suppressing testosterone levels. PMID:17402723

  9. Self-organization of surfactant molecules on solid surface: an STM study of sodium alkyl sulfonates [rapid communication

    NASA Astrophysics Data System (ADS)

    Yin, Xiu-Li; Wan, Li-Jun; Yang, Zheng-Yu; Yu, Jia-Yong

    2005-02-01

    Adsorption and self-organization of sodium alkyl sulfonates (STS and SHS) on HOPG have been studied by using in situ scanning tunneling microscopy (STM). Both SHS and STS molecules adsorb on HOPG surface and form long-range well-ordered monolayers. The molecular rows and the axes of alkyl chain of the molecules cross each other at angles of 60° and 90° in the STS and SHS layers, respectively. Molecular details such as sulfonate functional group (head) and alkyl chain are clearly imaged. The neighboring molecules in different rows form a "head to head" configuration. Structural models for the molecular arrangement of the two adlayers are proposed.

  10. Sulfonyl and phosphoryl azides: going further beyond the click realm of alkyl and aryl azides.

    PubMed

    Kim, Seok Hwan; Park, Sae Hume; Choi, Ji Ho; Chang, Sukbok

    2011-10-01

    Whereas alkyl and aryl azides readily react with terminal alkynes to afford 1,4-disubstituted-1,2,3-triazoles in excellent yields and selectivity in the presence of a copper catalyst, sulfonyl, phosphoryl, and certain acyl azides allow additional chemistry upon ring-opening of the corresponding copper-triazole intermediates. The amazingly versatile new chemistry stems from the high reactivity of a ring-opened ketenimine intermediate, with which a wide range of nucleophiles react to give multicomponent products. Among those nucleophiles, amines, alcohols, water, and heterocyclic compounds are especially capable of being involved in this new chemistry. PMID:21748856

  11. Auxiliary-assisted palladium-catalyzed arylation and alkylation of sp2 and sp3 carbon-hydrogen bonds.

    PubMed

    Shabashov, Dmitry; Daugulis, Olafs

    2010-03-24

    We have developed a method for auxiliary-directed, palladium-catalyzed beta-arylation and alkylation of sp(3) and sp(2) C-H bonds in carboxylic acid derivatives. The method employs a carboxylic acid 2-methylthioaniline- or 8-aminoquinoline amide substrate, aryl or alkyl iodide coupling partner, palladium acetate catalyst, and an inorganic base. By employing 2-methylthioaniline auxiliary, selective monoarylation of primary sp(3) C-H bonds can be achieved. If arylation of secondary sp(3) C-H bonds is desired, 8-aminoquinoline auxiliary may be used. For alkylation of sp(3) and sp(2) C-H bonds, 8-aminoquinoline auxiliary affords the best results. Some functional group tolerance is observed and amino- and hydroxy-acid derivatives can be functionalized. Preliminary mechanistic studies have been performed. A palladacycle intermediate has been isolated, characterized by X-ray crystallography, and its reactions have been studied. PMID:20175511

  12. Mechanism and Selectivity in Nickel-Catalyzed Cross-Electrophile Coupling of Aryl Halides with Alkyl Halides

    PubMed Central

    Biswas, Soumik; Weix, Daniel J.

    2013-01-01

    The direct cross-coupling of two different electrophiles, such as an aryl halide with an alkyl halide, offers many advantages over conventional cross-coupling methods that require a carbon nucleophile. Despite its promise as a versatile synthetic strategy, a limited understanding of the mechanism and origin of cross selectivity has hindered progress in reaction development and design. Herein, we shed light on the mechanism for the nickel-catalyzed cross-electrophile coupling of aryl halides with alkyl halides and demonstrate that the selectivity arises from an unusual catalytic cycle that combines both polar and radical steps to form the new C-C bond. PMID:23952217

  13. Computational and experimental investigations of one-step conversion of poly(carbonate)s into value-added poly(aryl ether sulfone)s.

    PubMed

    Jones, Gavin O; Yuen, Alexander; Wojtecki, Rudy J; Hedrick, James L; García, Jeannette M

    2016-07-12

    It is estimated that ∼2.7 million tons poly(carbonate)s (PCs) are produced annually worldwide. In 2008, retailers pulled products from store shelves after reports of bisphenol A (BPA) leaching from baby bottles, reusable drink bottles, and other retail products. Since PCs are not typically recycled, a need for the repurposing of the PC waste has arisen. We report the one-step synthesis of poly(aryl ether sulfone)s (PSUs) from the depolymerization of PCs and in situ polycondensation with bis(aryl fluorides) in the presence of carbonate salts. PSUs are high-performance engineering thermoplastics that are commonly used for reverse osmosis and water purification membranes, medical equipment, as well as high temperature applications. PSUs generated through this cascade approach were isolated in high purity and yield with the expected thermal properties and represent a procedure for direct conversion of one class of polymer to another in a single step. Computational investigations performed with density functional theory predict that the carbonate salt plays two important catalytic roles in this reaction: it decomposes the PCs by nucleophilic attack, and in the subsequent polyether formation process, it promotes the reaction of phenolate dimers formed in situ with the aryl fluorides present. We envision repurposing poly(BPA carbonate) for the production of value-added polymers. PMID:27354514

  14. Application of a C2-symmetric copper carbenoid in the enantioselective hydrosilylation of dialkyl and aryl-alkyl ketones.

    PubMed

    Albright, Abigail; Gawley, Robert E

    2011-12-14

    We report excellent reactivity and enantioselectivity of a C(2)-symmetric copper-bound N-heterocyclic carbene (NHC) in the hydrosilylation of a variety of structurally diverse ketones. This catalyst exhibits extraordinary enantioselctivity in the reduction of such challenging substrates as 2-butanone and 3-hexanone. Even at low catalyst loading (2.0 mol %), the reactions occur in under an hour at room temperature and often do not require purification beyond catalyst and solvent removal. The scope of this transformation was investigated in the reduction of 10 aryl-alkyl and alkyl-alkyl ketones. PMID:22074559

  15. Application of a C2-Symmetric Copper Carbenoid in the Enantioselective Hydrosilylation of Dialkyl and Aryl Alkyl Ketones

    PubMed Central

    Albright, Abigail; Gawley, Robert E.

    2011-01-01

    We report excellent reactivity and enantioselectivity of a C2-symmetric copper-bound N-heterocyclic carbene (NHC) in the hydrosilylation of a variety of structurally diverse ketones. This catalyst exhibits extraordinary enantioselctivity in the reduction of such challenging substrates as 2-butanone and 3-hexanone. Even at low catalyst loading (2.0 mol%) the reactions occur in under an hour at room temperature and often do not require purification beyond catalyst and solvent removal. The scope of this transformation was investigated in the reduction of ten aryl-alkyl and alkyl-alkyl ketones. PMID:22074559

  16. Alkyl and aryl sulfonyl p-pyridine ethanone oximes are efficient DNA photo-cleavage agents.

    PubMed

    Andreou, Nicolaos-Panagiotis; Dafnopoulos, Konstantinos; Tortopidis, Christos; Koumbis, Alexandros E; Koffa, Maria; Psomas, George; Fylaktakidou, Konstantina C

    2016-05-01

    Sulfonyloxyl radicals, readily generated upon UV irradiation of p-pyridine sulfonyl ethanone oxime derivatives, effectively cleave DNA, in a pH independent manner, and under either aerobic or anaerobic conditions. p-Pyridine sulfonyl ethanone oxime derivatives were synthesized from the reaction of p-pyridine ethanone oxime with the corresponding sulfonyl chlorides in good to excellent yields. All compounds, at a concentration of 100μM, were irradiated at 312nm for 15min, after incubation with supercoiled circular pBluescript KS II DNA and resulted in extended single- and double- strand cleavages. The cleavage ability was found to be concentration dependent, with some derivatives exhibiting activity even at nanomolar levels. Besides that, p-pyridine sulfonyl ethanone oxime derivatives showed good affinity to DNA, as it was observed with UV interaction and viscosity experiments with CT DNA and competitive studies with ethidium bromide. The compounds interact to CT DNA probably by non-classical intercalation (i.e. groove-binding) and at a second step they may intercalate within the DNA base pairs. The fluorescence emission spectra of pre-treated EB-DNA exhibited a significant or moderate quenching. Comparing with the known aryl carbonyloxyl radicals the sulfonyloxyl ones are more powerful, with both aryl and alkyl sulfonyl substituted derivatives to exhibit DNA photo-cleaving ability, in significantly lower concentrations. These properties may serve in the discovery of new leads for "on demand" biotechnological and medical applications. PMID:26945644

  17. Effect of linear alkyl benzene sulfonate on germination of spores of the aquatic fern Ceratopteris thalictroides

    SciTech Connect

    Singh, J.; Devi, S. )

    1989-07-01

    Validity of fern spore germination bioassays for the effects of environmental pollution was established by many researchers. Some workers studied the phytotoxicity of linear alkyl benzene sulfonate (LAS) on the spores of Diplazium esculentum and observed that LAS levels above 0.001% are toxic to fern spores. Water pollution due to synthetic detergents has been increasing continuously during the last few years due to their extensive use in domestic life, agriculture and industry. These detergents are among the most common pollutants responsible for water pollution. In view of this fact, the phytotoxicity of LAS on germination of an aquatic fern Ceratopteris thalictroides spores was studied. However, in these studies, only germination pattern was taken as index and no observations were made on the developmental stages.

  18. Radical Hydrodeiodination of Aryl, Alkenyl, Alkynyl, and Alkyl Iodides with an Alcoholate as Organic Chain Reductant through Electron Catalysis.

    PubMed

    Dewanji, Abhishek; Mück-Lichtenfeld, Christian; Studer, Armido

    2016-06-01

    A simple and efficient method for radical hydrodeiodination is reported. The novel approach uses electron catalysis. In situ generated Na-alcoholates are introduced as radical chain reducing reagents and reactions work with O2 as cheap initiator. Hydrodeiodination works on aryl, alkenyl, alkynyl iodides and a tert-alkyl iodide also gets reduced applying the method. Albeit less general, the method is also applicable to the reduction of aryl bromides. The novel reagent is successfully used to conduct typical reductive radical cyclization reactions and mechanistic studies are reported. PMID:27101530

  19. Crystal structures of three N-(aryl­sulfon­yl)-4-fluoro­benzamides

    PubMed Central

    Suchetan, P. A.; Naveen, S.; Lokanath, N. K.; Srivishnu, K. S.; Supriya, G. M.; Lakshmikantha, H. N.

    2016-01-01

    The crystal structures of three N-aryl­sulfonyl-4-fluoro­benzamides, namely 4-fluoro-N-(2-methyl­phenyl­sulfon­yl)benzamide, C14H12FNO3S, (I), N-(2-chloro­phenyl­sulfon­yl)-4-fluorobenzamide, C13H9ClFNO3S, (II), and N-(4-chloro­phenyl­sulfon­yl)-4-fluoro­benzamide monohydrate, C13H9ClFNO3S·H2O, (III), are described and compared with related structures. The asymmetric unit of (I) contains two independent mol­ecules (A and B), while that of (II) contains just one mol­ecule, and that of (III) contains a mol­ecule of water in addition to one main mol­ecule. The dihedral angle between the benzene rings is 82.83 (11)° in mol­ecule A and 85.01 (10)° in mol­ecule B of (I), compared to 89.91 (10)° in (II) and 81.82 (11)° in (III). The crystal structure of (I) features strong N—H⋯O hydrogen bonds between the A and B mol­ecules, resulting in an R 4 4(16) tetra­meric unit. These tetra­meric units are connected into sheets in the bc plane by various C—H⋯O inter­actions, and adjacent sheets are further inter­linked via C—H⋯πar­yl inter­actions, forming a three-dimensional architecture. The crystal structure is further stabilized by πar­yl–πar­yl and S=O⋯πar­yl inter­actions. In the crystal of (II), mol­ecules are connected into R 2 2(8) and R 2 2(14) dimers via N—H⋯O hydrogen bonds and C—H⋯O inter­actions, respectively; the dimers are further inter­connected via a weak C=O⋯πar­yl inter­action, leading to the formation of chains along [1-10]. In the crystal of (III), N—H⋯O and O—H⋯O hydrogen bonds involving both the main mol­ecule and the solvent water mol­ecule results in the formation of sheets parallel to the bc plane. The sheets are further connected by C—H⋯O inter­actions and weak C—Cl⋯πar­yl, C—F⋯πar­yl and S=O⋯πar­yl inter­actions, forming a three-dimensional architecture. PMID:27375892

  20. Evaluation of O-alkyl and aryl sulfonyl aromatic and heteroaromatic amidoximes as novel potent DNA photo-cleavers.

    PubMed

    Papastergiou, A; Perontsis, S; Gritzapis, P; Koumbis, A E; Koffa, M; Psomas, G; Fylaktakidou, K C

    2016-03-01

    Several stable O-alkyl and aryl sulfonyl conjugated p-nitro-Ph and o-, m-, p-pyridine N'-hydroxy imidamides, were subjected to UV irradiation at 312 nm with supercoiled circular plasmid DNA pBluescript KS II. The generated amidinyl and sulfonyloxyl radicals led to effective DNA photo-cleavage. Both alkyl and aryl sulfonyl derivatives were active and the order p-pyridine > p-nitro-Ph > o-pyridine > m-pyridine was schematized for the N'-hydroxy imidamides moiety. Calf thymus-DNA affinity studies which comprised UV interactions, viscosity experiments and competitive studies with ethidium bromide showed good to excellent affinity of the compounds. These properties revealed sulfonyl amidoximes as novel effective DNA-photo-cleavers and may serve in the discovery of new leads for "on demand" biotechnological and medical applications. PMID:26959855

  1. 3-Alkyl-3-(alkylamino)indolin-2-ones via Base-Mediated C-Arylation of 2-Nitrobenzenesulfonamides.

    PubMed

    Giménez-Navarro, Vanesa; Volná, Tereza; Krchňák, Viktor

    2015-08-10

    Resin-bound intermediates prepared from polymer-supported amino acid esters, 2-nitrobenezenesulfonyl chlorides, and alcohols were used to synthesize 3-alkyl-3-(alkylamino) indolin-2-ones. The key step of the reaction sequence was the formation of a quaternary carbon via the base-mediated C-arylation of 2-nitrobenzenesulfonamides. The cleavage of the acyclic precursors from the resin and subsequent reduction of the nitro group by Zn in acetic acid triggered the spontaneous cyclization of the arylated compounds to indolinones. The synthesis was carried out using simple commercially available building blocks under mild conditions and provided the 3,3-disubstituted indolinone derivatives with good overall yields however, the arylation reaction resulted in the epimerization of the quaternary carbon. PMID:26181142

  2. Unsymmetrical alkyl aryl thiourae compounds for use as cerebral blood flow tracers. [Rats

    SciTech Connect

    Goldman, S.S.; Haas, W.K.; Ransohoff, J.

    1980-06-01

    The synthesis and characterization of an homologous series of inert nonvolatile /sup 14/C-labeled unsymmetrical alkyl aryl thiourea compounds is described for their use as regional blood flow (rCBF) tracers employing autoradiographic procedures. In alert normocapnic rats the single-pass extraction values into brain for these thioureas were found ranging from 0.497 for 1-methyl-3-phenylthiourea to 0.730 for 1-butyl-3-phenylthiourea. The commonly used rCBF tracers (14C) antipyrine and (14C) iodoantipyrine had single-pass extraction values of 0.451 and 0.553, respectively. Since 1-butyl-3-phenylthiourea diffused most readily into rat brain it was chosen as a potentially valuable rCBF tracer. Employing 1-butyl-3-phenylthiourea to measure rCBF nd its empirically derived brain extraction values the following flow rates in normocapnic rats were found: 3.2 ml . g-1 . min-1 for cochlear nucleus: 3.0 for inferior colliculus; 2.5 for medical geniculate; 1.9 for pontine gray and hypothalamus; 1.7 for caudate and cerebral cortex; and 1.2 for cerebellar gray and 0.41 to 0.50 for white matter structures. It was concluded from these studies that 1-butyl-3-phenylthiourea is more advantageous than iodoantipyrine for measuring rCBF, especially in those areas that possess very rapid rates of flow.

  3. Aryl-alkyl-lysines: Membrane-Active Small Molecules Active against Murine Model of Burn Infection.

    PubMed

    Ghosh, Chandradhish; Manjunath, Goutham B; Konai, Mohini M; Uppu, Divakara S S M; Paramanandham, Krishnamoorthy; Shome, Bibek R; Ravikumar, Raju; Haldar, Jayanta

    2016-02-12

    Infections caused by drug-resistant Gram-negative pathogens continue to be significant contributors to human morbidity. The recent advent of New Delhi metallo-β-lactamase-1 (blaNDM-1) producing pathogens, against which few drugs remain active, has aggravated the problem even further. This paper shows that aryl-alkyl-lysines, membrane-active small molecules, are effective in treating infections caused by Gram-negative pathogens. One of the compounds of the study was effective in killing planktonic cells as well as dispersing biofilms of Gram-negative pathogens. The compound was extremely effective in disrupting preformed biofilms and did not select resistant bacteria in multiple passages. The compound retained activity in different physiological conditions and did not induce any toxic effect in female Balb/c mice until concentrations of 17.5 mg/kg. In a murine model of Acinetobacter baumannii burn infection, the compound was able to bring the bacterial burden down significantly upon topical application for 7 days. PMID:27624962

  4. Nickel-Catalyzed Decarboxylative Cross-Coupling of Perfluorobenzoates with Aryl Halides and Sulfonates

    PubMed Central

    2016-01-01

    A Ni-catalyzed method for the coupling of perfluorobenzoates with aryl halides and pseudohalides is described. Aryl iodides, bromides, chlorides, triflates, and tosylates participate in these transformations to afford the products in good yields. Penta-, tetra-, and trifluorinated biaryl compounds are obtained using these newly developed Ni-catalyzed decarboxylative cross-coupling reactions. PMID:25700128

  5. Pyrolysis of Aryl Sulfonate Esters in the Absence of Solvent: E1 or E2? A Puzzle for the Organic Laboratory

    ERIC Educational Resources Information Center

    Nash, John J.; Leininger, Marnie A.; Keyes, Kurt

    2008-01-01

    The aryl sulfonate ester, menthyl N-acetylsulfanilate, is synthesized from N-acetylsulfanilyl chloride and menthol in pyridine, then pyrolyzed (thermally decomposed) at reduced pressure. The volatile (elimination) products of the reaction are analyzed using gas chromatography, and the resulting product distribution is used to determine whether the…

  6. Comparative analysis of the conformations of symmetrically and asymmetrically deca- and undecasubstituted porphyrins bearing meso-alkyl or -aryl groups

    SciTech Connect

    Senge, M.O.; Medforth, C.J.; Forsyth, T.P.

    1997-03-12

    Conformational analysis of highly substituted porphyrins, has potential implications for modeling the behavior of macrocycles in tetrapyrrole-containing protein complexes and during catalytic reactions. In order to study the influence of different substituent patterns of the conformation of the porphyrin macrocycle, a series of metal free and nickel(II) decasubstituted porphyrins bearing aryl or ethyl groups at opposite meso positions and alkyl groups at the pyrrole positions have been synthesized and characterized by X-ray crystallography. Crystal structures of the free-base porphyrins with 5,15-diaryl substituents showed negligible out-of-plane distortion but a large amount of in-plane distortion along the 5,15-axis accompanied by large bond angle changes similar to those previously seen for related porphyrins with 5,15-dialkyl substituents. Nickel(II) complexes of the 5,15-diaryl-substituted porphyrins show planar or modestly nonplanar conformations, suggesting that these complexes are not intrinsically nonplanar, whereas a complex with 5,15-diethyl substituents has a very ruffled conformation similar to those observed for related complexes with other metals. The nickel(II) complexes are also elongated along the 5,15-axis in a qualitatively similar but less dramatic fashion than are the free-base porphyrins. Spectroscopic studies ({sup 1}H NMR, optical, and resonance Raman spectroscopy) suggest that conformations similar to those determined by X-ray crystallography are present in solution for the 5,15-disubstituted porphyrins containing both aryl and alkyl mesosubstituents were also investigated. Metal-free 5,15-dialkyl- and 5,15-diaryl-substituted porphyrins. Several asymmetric nickel(II) and metal-free deca- and undecasubstituted porphyrins containing both aryl and alkyl mesosubstituents were also investigated.

  7. Nickel-Catalyzed Reductive Cross-Coupling of Aryl Bromides with Alkyl Bromides: Et3N as the Terminal Reductant.

    PubMed

    Duan, Zhengli; Li, Wu; Lei, Aiwen

    2016-08-19

    Reductive cross-coupling has emerged as a direct method for the construction of carbon-carbon bonds. Most cobalt-, nickel-, and palladium-catalyzed reductive cross-coupling reactions to date are limited to stoichiometric Mn(0) or Zn(0) as the reductant. One nickel-catalyzed cross-coupling paradigm using Et3N as the terminal reductant is reported. By using this photoredox catalysis and nickel catalysis approach, a direct Csp(2)-Csp(3) reductive cross-coupling of aryl bromides with alkyl bromides is achieved under mild conditions without stoichiometric metal reductants. PMID:27472556

  8. Effect of ionic additives on the elution of sodium aryl sulfonates in supercritical fluid chromatography.

    PubMed

    Zheng, J; Taylor, L T; Pinkston, J David; Mangels, M L

    2005-08-01

    Addition of a small amount of polar solvent (i.e., modifier) to CO2 in packed column supercritical fluid chromatography (SFC) has shown major improvements in both polar analyte solubility and interaction of the polar analyte with the stationary phase. Recently, the addition of an ionic component (i.e., additive) to the primary modifier by one of us has been shown to extend even further the application of SFC to polar analytes. In this work, the effect of various ionic additives on the elution of ionic compounds, such as sodium 4-dodecylbenzene sulfonate and sodium 4-octylbenene sulfonate, has been studied. The additives were lithium acetate, ammonium acetate, tetramethylammonium acetate, tetrabutylammonium acetate, and ammonium chloride dissolved in methanol. Three stationary phases with different degrees of deactivation were considered: conventional cyanopropyl, deltabond cyanopropyl, and bare silica. The effect of additive concentration and additive functionality on analyte retention was investigated. Sodium 4-dodecylbenzene sulfonate was successfully eluted using all the additives with good peak shape under isocratic/isobaric/isothermal conditions. Different additives, however, yielded different retention times and in some cases different peak shapes. PMID:16035365

  9. Synthesis of functionalized 5-substituted thiazolidine-2-thiones via adscititious xanthate-promoted radical cyclization of allyl(alkyl/aryl)dithiocarbamates.

    PubMed

    Gao, Simiao; Zhang, Yu; Dong, Jun; Chen, Ning; Xu, Jiaxi

    2016-01-21

    Functionalized 5-substituted thiazolidine-2-thiones were synthesized efficiently from alkyl allyl(alkyl/aryl)-dithiocarbamates via radical cyclization with the corresponding S-alkyl O-ethyl xanthates as the adscititious radical precursors. The application of the adscititious radical precursors improves not only the yields, but also the efficiency in the radical cyclization reaction significantly. The current adscititious radical precursor method provides a new strategy for the achievement and improvement of some radical reactions which are hardly or difficultly realized by the traditional direct methods. PMID:26626401

  10. Lewis Acid Assisted Nickel-Catalyzed Cross-Coupling of Aryl Methyl Ethers by C-O Bond-Cleaving Alkylation: Prevention of Undesired β-Hydride Elimination.

    PubMed

    Liu, Xiangqian; Hsiao, Chien-Chi; Kalvet, Indrek; Leiendecker, Matthias; Guo, Lin; Schoenebeck, Franziska; Rueping, Magnus

    2016-05-10

    In the presence of trialkylaluminum reagents, diverse aryl methyl ethers can be transformed into valuable products by C-O bond-cleaving alkylation, for the first time without the limiting β-hydride elimination. This new nickel-catalyzed dealkoxylative alkylation method enables powerful orthogonal synthetic strategies for the transformation of a variety of naturally occurring and easily accessible anisole derivatives. The directing and/or activating properties of aromatic methoxy groups are utilized first, before they are replaced by alkyl chains in a subsequent coupling process. PMID:27062726

  11. H2O2/UV-C treatment of the commercially important aryl sulfonates H-, K-, J-acid and Para base: assessment of photodegradation kinetics and products.

    PubMed

    Arslan-Alaton, Idil; Olmez-Hanci, Tugba; Gursoy, Betul Hande; Tureli, Gokce

    2009-07-01

    H2O2/UV-C treatment of four commercially important aryl sulfonates (naphthalene sulfonic acids H-acid, K-acid, J-acid and benzene sulfonic acid Para base) in aqueous solutions was investigated. Photodegradation kinetics was followed in terms of changes brought about in the parent compound concentration via high performance liquid chromatography, as well as abatement of the collective environmental parameters COD and TOC. The efficiency of H2O2/UV-C treatment was also evaluated by determining H2O2 consumption rates throughout the reactions whereas the formation of intermediates (photodegradation products) was traced by means of mass spectrometry. Our experimental findings indicated that especially trisulfonated K-acid was not very prone to photochemical degradation, closely followed by the other studied aryl sulfonates. The highest abatement rates (treatment efficiencies and reaction kinetics) were obtained for the relatively simpler structured Para base. Mass spectrometric analysis revealed that the early stages of H2O2/UV-C treatment followed a (.)OH-addition mechanism as mainly hydroxylated photodegradation products were qualitatively identified. PMID:19481776

  12. Recognition of N-alkyl and N-aryl acetamides by N-alkyl ammonium resorcinarene chlorides.

    PubMed

    Beyeh, N Kodiah; Ala-Korpi, Altti; Cetina, Mario; Valkonen, Arto; Rissanen, Kari

    2014-11-10

    N-alkyl ammonium resorcinarene chlorides are stabilized by an intricate array of intra- and intermolecular hydrogen bonds that leads to cavitand-like structures. Depending on the upper-rim substituents, self-inclusion was observed in solution and in the solid state. The self-inclusion can be disrupted at higher temperatures, whereas in the presence of small guests the self-included dimers spontaneously reorganize to 1:1 host-guest complexes. These host compounds show an interesting ability to bind a series of N-alkyl acetamide guests through intermolecular hydrogen bonds involving the carbonyl oxygen (C=O) atoms and the amide (NH) groups of the guests, the chloride anions (Cl(-)) and ammonium (NH2(+)) cations of the hosts, and also through CH⋅⋅⋅π interactions between the hosts and guests. The self-included and host-guest complexes were studied by single-crystal X-ray diffraction, NMR titration, and mass spectrometry. PMID:25257765

  13. One-Pot Synthesis and Evaluation of Antileishmanial Activities of Functionalized S-Alkyl/Aryl Benzothiazole-2-carbothioate Scaffold.

    PubMed

    Dar, Ajaz A; Shadab, M; Khan, Suman; Ali, Nahid; Khan, Abu T

    2016-04-15

    The synthesis of hitherto unreported S-alkyl/aryl benzothiazole-2-carbothioate is reported from thiols, oxalyl chloride, and 2-aminothiophenols using 10 mol % n-tetrabutylammonium iodide (TBAI) as catalyst in acetonitrile through multicomponent reaction (MCR) strategy. The present protocol favored formation of benzothiazoles and thioesters via simultaneous formation of C-N and C-S bonds in good yields with a wide range of substrates. A few of the synthesized derivatives were evaluated for their antimicrobial activity against the protozoan parasite Leishmania donovani, a causative agent of visceral leishmaniasis (VL). Further, these compounds displayed no toxicity toward macrophage RAW 264.7 cells and are therefore nontoxic and effective antileishmanial leads. In silico docking studies were performed to understand the possible binding site interaction with trypanothione reductase (TryR). PMID:26999637

  14. N,N'-Unsubstituted Naphthodithiophene Diimide: Synthesis and Derivatization via N-Alkylation and -Arylation.

    PubMed

    Nakano, Masahiro; Sawamoto, Masanori; Yuki, Mizue; Takimiya, Kazuo

    2016-08-01

    An efficient and scalable method for the synthesis of N,N'-unsubstituted naphtho[2,3-b:6,7-b']dithiophene-4,5,9,10-tetracarboxylic diimide (NDTI) was newly developed, and the compound was utilized in the Mitsunobu reaction and copper-catalyzed coupling reaction with phenyl boronic acids to synthesize a range of N-alkyl- and phenyl-substituted NDTI derivatives. The new synthetic protocol to NDTI derivatives is advantageous over the previously reported one in terms of the amenability to large-scale synthesis and compatibility with the synthesis of a wide range of N-alkyl and phenyl derivatives, which can in turn pave the way to wide application of NDTI derivatives into electronic materials. PMID:27428656

  15. [Leukoderma caused by chemicals: mechanisms underlying 4-alkyl/aryl-substituted phenols- and rhododendrol-induced melanocyte loss].

    PubMed

    Nishimaki-Mogami, Tomoko

    2015-01-01

    Chemical leukoderma is a skin depigmentation disorder known to occur in manufactural workplace through contact with chemicals, such as monobenzyl ether of hydroquinone (MBEH) and 4-tert- butylphenol (4-TBP). In the skin depigmented -legions induced by these chemicals, the number of melanocyte was severely decreased. Anti-melanoma agent 4-cysteaminylphenol (4-SCAP) and its derivatives are also known to cause leukoderma. Evidence has accumulated supporting that typical class of chemicals causing leukoderma is "4-alkyl/aryl-substituted phenols/catechols", which are structurally similar to melanin precursor tyrosine. Tyrosinase-mediated oxidation of these chemicals yields toxic ortho-quinones which bind to cellular proteins and produce reactive oxygen species. Accordingly, this tyrosinase-dependent metabolic activation is thought to cause melanocyte-specific damage and subsequent immune reactions toward melanocytes. Recently, rhododendrol, an inhibitor of tyrosinase developed for so-called lightening/whitening cosmetics, was shown to cause leukoderma in the users. In this review, I document the causes of known chemical leukoderma and rhododendrol- induced leukoderma, focusing on their common mechanisms underlying melanocyte loss. PMID:26821466

  16. Inhibition of biogas production by alkyl benzene sulfonates (LAS) in a screening test for anaerobic biodegradability.

    PubMed

    Garcia, M Teresa; Campos, Encarna; Dalmau, Manel; Illán, Patricia; Sánchez-Leal, Joaquin

    2006-02-01

    The effect of the inoculum source on the digestion of linear alkylbenzene sulfonates (LAS) under anaerobic conditions has been investigated. The potential for primary and ultimate LAS biodegradation of anaerobic sludge samples obtained from wastewater treatment plants (WWTPs) of different geographical locations was studied applying a batch test system. It was found that only 4-22% of the LAS added to the batch anaerobic digesters was primarily transformed suggesting a poor primary degradation of the LAS molecule in anaerobic discontinuous systems. Regarding ultimate biodegradation, the addition of LAS to the batch anaerobic digesters caused a reduction on the extent of biogas production. Significant differences in the inhibition extent of the biogas production were observed (4-26%) depending on the sludge used as inoculum. Effect of the surfactant on the anaerobic microorganisms was correlated with its concentration in the aqueous phase. Sorption of LAS on anaerobic sludge affects its toxicity by depletion of the available fraction of the surfactant. LAS content on sludge was related to the total amount of calcium and magnesium extractable ions. The presence of divalent cations promote the association of LAS with anaerobic sludge reducing its bioavailability and the extent of its inhibitory effect on the biogas production. PMID:16453170

  17. Photodissociation of alkyl and aryl iodides and effect of fluorination: Analysis of proposed mechanisms and vertical excitations by spin-orbit ab initio study

    NASA Astrophysics Data System (ADS)

    Ajitha, D.; Fedorov, D. G.; Finley, J. P.; Hirao, K.

    2002-10-01

    An ab initio study of the vertical electronic excitations in CX3I, C6X5H, and C6X5I (X=H and F) is presented. All-electron basis sets are used and the relativistic effects are accounted for with the relativistic elimination of small components scheme. The structures are optimized with the complete active space self-consistent field approach and the excitation energies are computed with the spin-orbit multiconfiguration quasidegenerate perturbation theory. The n-σ* transitions of CX3I, low-lying π-π* transitions of C6X5H, and low-lying n-σ*, π-π*, and π-σ* transitions of C6X5I are elucidated. For CH3I, energy values of parallel and perpendicular transitions differ from experimental values by 455 and 1156 cm-1, respectively. Effects of fluorination are emphasized, it is found that fluorination increases the gap between 3Q0 and 1Q1 transitions and increase is substantially more in aryl iodides than in alkyl iodides. Electronic factors influencing increased I* quantum yield in the photodissociation on fluorination of alkyl iodides is attributed to increased gap between 3Q0 and 1Q1 transitions reducing curve crossing probability and for aryl iodides there is additional role by phenyl transitions. A correlation diagram illustrating transitions of aryl iodides is presented.

  18. The relative rates of thiol-thioester exchange and hydrolysis for alkyl and aryl thioalkanoates in water.

    PubMed

    Bracher, Paul J; Snyder, Phillip W; Bohall, Brooks R; Whitesides, George M

    2011-10-01

    This article reports rate constants for thiol-thioester exchange (k (ex)), and for acid-mediated (k (a)), base-mediated (k (b)), and pH-independent (k (w)) hydrolysis of S-methyl thioacetate and S-phenyl 5-dimethylamino-5-oxo-thiopentanoate-model alkyl and aryl thioalkanoates, respectively-in water. Reactions such as thiol-thioester exchange or aminolysis could have generated molecular complexity on early Earth, but for thioesters to have played important roles in the origin of life, constructive reactions would have needed to compete effectively with hydrolysis under prebiotic conditions. Knowledge of the kinetics of competition between exchange and hydrolysis is also useful in the optimization of systems where exchange is used in applications such as self-assembly or reversible binding. For the alkyl thioester S-methyl thioacetate, which has been synthesized in simulated prebiotic hydrothermal vents, k (a) = 1.5 × 10(-5) M(-1) s(-1), k (b) = 1.6 × 10(-1) M(-1) s(-1), and k (w) = 3.6 × 10(-8) s(-1). At pH 7 and 23°C, the half-life for hydrolysis is 155 days. The second-order rate constant for thiol-thioester exchange between S-methyl thioacetate and 2-sulfonatoethanethiolate is k (ex) = 1.7 M(-1) s(-1). At pH 7 and 23°C, with [R″S(H)] = 1 mM, the half-life of the exchange reaction is 38 h. These results confirm that conditions (pH, temperature, pK (a) of the thiol) exist where prebiotically relevant thioesters can survive hydrolysis in water for long periods of time and rates of thiol-thioester exchange exceed those of hydrolysis by several orders of magnitude. PMID:21728078

  19. Halo, Alkyl, Aryl, and Bis(imido) Complexes of Niobium Supported by the β-Diketiminato Ligand

    PubMed Central

    Tomson, Neil C.; Arnold, John; Bergman, Robert G.

    2010-01-01

    Synthesis of the complex (BDI)Nb(NtBu)Cl2py (BDI = HC[C(Me)N(2,6-iPr2-C6H3)]2) was achieved in high yield following the treatment of Nb(NtBu)Cl3py2 with Li(BDI)(OEt2). Substitution of the chlorides for fluorides was effected by introducing 2.0 equiv of Me3SnF in toluene, providing the pyridine-coordinated difluoride complex (BDI)Nb(NtBu)F2py in modest yield. The pyridine ligands from both halide compounds were removed by treatment of the pyridine adducts with B(C6F5)3, affording the Lewis base-free complexes (BDI)Nb(NtBu)X2 (X = Cl, F). Additionally, the Lewis base-free dichlorides of the tBu-imido and Ar-imido (Ar = 2,6-iPr2-C6H3) complexes were obtained following treatment of Nb(NR)Cl3(dme) (R = tBu, Ar) with Li(BDI)(OEt2). The pyridine-coordinated dichloride was alkylated and arylated to form the dimethyl complex (BDI)Nb(NtBu)Me2 (described previously, see text) and the mono(p-tolyl) complex (BDI)Nb(NtBu)Cl(p-tol), the latter of which was methylated with MeMgBr to yield the mixed alkyl/aryl complex (BDI)Nb(NtBu)Me(p-tol) in good yield. A rare example of a Group 5 bis(tBu-imido) species was synthesized in good yield via treatment of (BDI)Nb(NtBu)Cl2py with 2.0 equiv of LiNHtBu to form (BDI)Nb(NtBu)2py. Exchange of the coordinated pyridine ligand for either pyridine-d5 or dmap (p-(dimethylamino)pyridine) was shown to occur through a dissociative mechanism, allowing for removal of the coordinated Lewis base by treatment with B(C6F5)3. The resulting average C2v-symmetric tetracoordinate bis(imido) complex (BDI)Nb(NtBu)2 was characterized in solution by NMR spectroscopy and observed to undergo clean thermal decomposition to yield (BDI#)Nb(NtBu)(NHtBu) (BDI# = H2C=C(NAr)CH=C(NAr)Me) over several hours at room temperature. Treatment of the four-coordinate bis(imido) with tBuNCO resulted in clean [2 + 2] cycloaddition to yield an oxaazametallacyclobutane complex, which was further observed to extrude tBuN=C=NtBu over 12 h at room temperature. The molecular structures of

  20. Efficient cross-coupling of aryl Grignard reagents with alkyl halides by recyclable ionic iron(III) complexes bearing a bis(phenol)-functionalized benzimidazolium cation.

    PubMed

    Xia, Chong-Liang; Xie, Cun-Fei; Wu, Yu-Feng; Sun, Hong-Mei; Shen, Qi; Zhang, Yong

    2013-12-14

    A novel bis(phenol)-functionalized benzimidazolium salt, 1,3-bis(3,5-di-tert-butyl-2-hydroxybenzyl)benzimidazolium chloride (H3LCl, 1), was designed and used to prepare ionic iron(III) complexes of the type [H3L][FeX4] (X = Cl, 2; X = Br, 3). Both 2 and 3 were characterized by elemental analysis, Raman spectroscopy, electrospray ionization mass spectrometry and X-ray crystallography. The catalytic performances of 2 and 3 in cross-coupling reactions using aryl Grignard reagents with primary and secondary alkyl halides bearing β-hydrogens were studied. This analysis shows that complex 2 has good potential for alkyl chloride-mediated coupling. In comparison, complex 3 showed slightly lower catalytic activity. After decanting the product contained in the ethereal layer, complex 2 could be recycled at least eight times without significant loss of catalytic activity. PMID:24145602

  1. The Branched-Chain Dodecylbenzene Sulfonate Degradation Pathway of Pseudomonas aeruginosa W51D Involves a Novel Route for Degradation of the Surfactant Lateral Alkyl Chain

    PubMed Central

    Campos-García, Jesús; Esteve, Abraham; Vázquez-Duhalt, Rafael; Ramos, Juán Luis; Soberón-Chávez, Gloria

    1999-01-01

    Pseudomonas aeruginosa W51D is able to grow by using branched-chain dodecylbenzene sulfonates (B-DBS) or the terpenic alcohol citronellol as a sole source of carbon. A mutant derived from this strain (W51M1) is unable to degrade citronellol but still grows on B-DBS, showing that the citronellol degradation route is not the main pathway involved in the degradation of the surfactant alkyl moiety. The structures of the main B-DBS isomers and of some intermediates were identified by gas chromatography-mass spectrometric analysis, and a possible catabolic route is proposed. PMID:10427075

  2. Methods and Mechanisms for Cross-Electrophile Coupling of Csp(2) Halides with Alkyl Electrophiles.

    PubMed

    Weix, Daniel J

    2015-06-16

    Cross-electrophile coupling, the cross-coupling of two different electrophiles, avoids the need for preformed carbon nucleophiles, but development of general methods has lagged behind cross-coupling and C-H functionalization. A central reason for this slow development is the challenge of selectively coupling two substrates that are alike in reactivity. This Account describes the discovery of generally cross-selective reactions of aryl halides and acyl halides with alkyl halides, the mechanistic studies that illuminated the underlying principles of these reactions, and the use of these fundamental principles in the rational design of new cross-electrophile coupling reactions. Although the coupling of two different electrophiles under reducing conditions often leads primarily to symmetric dimers, the subtle differences in reactivity of aryl halides and alkyl halides with nickel catalysts allowed for generally cross-selective coupling reactions. These conditions could also be extended to the coupling of acyl halides with alkyl halides. These reactions are exceptionally functional group tolerant and can be assembled on the benchtop. A combination of stoichiometric and catalytic studies on the mechanism of these reactions revealed an unusual radical-chain mechanism and suggests that selectivity arises from (1) the preference of nickel(0) for oxidative addition to aryl halides and acyl halides over alkyl halides and (2) the greater propensity of alkyl halides to form free radicals. Bipyridine-ligated arylnickel intermediates react with alkyl radicals to efficiently form, after reductive elimination, new C-C bonds. Finally, the resulting nickel(I) species is proposed to regenerate an alkyl radical to carry the chain. Examples of new reactions designed using these principles include carbonylative coupling of aryl halides with alkyl halides to form ketones, arylation of epoxides to form β-aryl alcohols, and coupling of benzyl sulfonate esters with aryl halides to form

  3. Methods and Mechanisms for Cross-Electrophile Coupling of Csp2 Halides with Alkyl Electrophiles

    PubMed Central

    2016-01-01

    Conspectus Cross-electrophile coupling, the cross-coupling of two different electrophiles, avoids the need for preformed carbon nucleophiles, but development of general methods has lagged behind cross-coupling and C–H functionalization. A central reason for this slow development is the challenge of selectively coupling two substrates that are alike in reactivity. This Account describes the discovery of generally cross-selective reactions of aryl halides and acyl halides with alkyl halides, the mechanistic studies that illuminated the underlying principles of these reactions, and the use of these fundamental principles in the rational design of new cross-electrophile coupling reactions. Although the coupling of two different electrophiles under reducing conditions often leads primarily to symmetric dimers, the subtle differences in reactivity of aryl halides and alkyl halides with nickel catalysts allowed for generally cross-selective coupling reactions. These conditions could also be extended to the coupling of acyl halides with alkyl halides. These reactions are exceptionally functional group tolerant and can be assembled on the benchtop. A combination of stoichiometric and catalytic studies on the mechanism of these reactions revealed an unusual radical-chain mechanism and suggests that selectivity arises from (1) the preference of nickel(0) for oxidative addition to aryl halides and acyl halides over alkyl halides and (2) the greater propensity of alkyl halides to form free radicals. Bipyridine-ligated arylnickel intermediates react with alkyl radicals to efficiently form, after reductive elimination, new C–C bonds. Finally, the resulting nickel(I) species is proposed to regenerate an alkyl radical to carry the chain. Examples of new reactions designed using these principles include carbonylative coupling of aryl halides with alkyl halides to form ketones, arylation of epoxides to form β-aryl alcohols, and coupling of benzyl sulfonate esters with aryl

  4. Organozinc Chemistry Enabled by Micellar Catalysis. Palladium-Catalyzed Cross-Couplings between Alkyl and Aryl Bromides in Water at Room Temperature

    PubMed Central

    Duplais, Christophe; Krasovskiy, Arkady; Lipshutz, Bruce H.

    2012-01-01

    Negishi-like cross-couplings between (functionalized) alkyl and aryl bromides are described. Despite the fact that organozinc reagents are intolerant of water, their formation as well as their use in an aqueous micellar environment is discussed herein. Each component of this complex series of events leading up to C–C bond formation has an important role which has been determined insofar as the type of zinc, amine ligand, surfactant, and palladium catalyst are concerned. In particular, the nature of the surfactant has been found to be crucial in order to obtain synthetically useful results involving highly reactive, moisture-sensitive organometallics. Neither organic solvent nor heat is required for these cross-couplings to occur; just add water. PMID:23539206

  5. Aryl-Alkyl-Lysines: Agents That Kill Planktonic Cells, Persister Cells, Biofilms of MRSA and Protect Mice from Skin-Infection

    PubMed Central

    Ghosh, Chandradhish; Manjunath, Goutham B.; Konai, Mohini M.; Uppu, Divakara S. S. M.; Hoque, Jiaul; Paramanandham, Krishnamoorthy; Shome, Bibek R.; Haldar, Jayanta

    2015-01-01

    Development of synthetic strategies to combat Staphylococcal infections, especially those caused by methicillin resistant Staphyloccus aureus (MRSA), needs immediate attention. In this manuscript we report the ability of aryl-alkyl-lysines, simple membrane active small molecules, to treat infections caused by planktonic cells, persister cells and biofilms of MRSA. A representative compound, NCK-10, did not induce development of resistance in planktonic cells in multiple passages and retained activity in varying environments of pH and salinity. At low concentrations the compound was able to depolarize and permeabilize the membranes of S. aureus persister cells rapidly. Treatment with the compound not only eradicated pre-formed MRSA biofilms, but also brought down viable counts in bacterial biofilms. In a murine model of MRSA skin infection, the compound was more effective than fusidic acid in bringing down the bacterial burden. Overall, this class of molecules bears potential as antibacterial agents against skin-infections. PMID:26669634

  6. Tunable Aryl Alkyl Ionic Liquids with Weakly Coordinating Tetrakis((1,1,1,3,3,3-hexafluoropropan-2-yl)oxy)borate [B(hfip)4 ] Anions.

    PubMed

    Kaliner, Maria; Rupp, Alexander; Krossing, Ingo; Strassner, Thomas

    2016-07-11

    Weakly coordinating borate or aluminate anions have recently been shown to yield interesting properties of the resulting ionic liquids (ILs). The same is true for large phenyl-substituted imidazolium cations, which can be tuned by the choice, position, or number of substituents on the aromatic ring. We were therefore interested to combine these aryl alkyl imidazolium cations with the weakly coordinating tetrakis((1,1,1,3,3,3-hexafluoropropan-2-yl)oxy)borate [B(hfip)4 ](-) anions to study the physical properties and viscosities of these ionic liquids. Despite the large size and high molecular weight of these readily available ILs, they are liquid at room temperature and show remarkably low glass transition points and relatively high decomposition temperatures. PMID:27333433

  7. Synthesis and Anticancer Activity of 2-(Alkyl-, Alkaryl-, Aryl-, Hetaryl-)-[1,2,4]triazolo[1,5-c]quinazolines

    PubMed Central

    Kovalenko, Sergiy I.; Antypenko, Lyudmyla M.; Bilyi, Andriy K.; Kholodnyak, Sergiy V.; Karpenko, Olexandr V.; Antypenko, Olexii M.; Mykhaylova, Natalya S.; Los, Tetyana I.; Kolomoets, Olexandra S.

    2013-01-01

    The combinatorial library of novel potential anticancer agents, namely, 2-(alkyl-, alkaryl-, aryl-, hetaryl-)[1,2,4]triazolo[1,5-c]quinazolines, was synthesized by the heterocyclization of the alkyl-, alkaryl-, aryl-, hetarylcarboxylic acid (3H-quinazoline-4-ylidene)hydrazides by oxidative heterocyclization of the 4-(arylidenehydrazino)quinazolines using bromine, and by the heterocyclization of N-(2-cyanophenyl)formimidic acid ethyl ester. The optimal method for synthesis of the s-triazolo[1,5-c]quinazolines appeared to be cyclocondensation of the corresponding carboxylic acid (3H-quinazoline-4-ylidene)hydrazides. The compounds’ structures were established by 1H, 13C NMR, LC- and EI-MS analysis. The in vitro screening of anticancer activity determined the most active compound to be 3,4,5-trimethoxy-N′-[quinazolin-4(3H)-ylidene]benzohydrazide (3.20) in micromolar concentrations with the GI50 level (MG_MID, GI50 is 2.29). Thus, the cancer cell lines whose growth is greatly inhibited by compound 3.20 are: non-small cell lung cancer (NCI-H522, GI50=0.34), CNS (SF-295, GI50=0.95), ovarian (OVCAR-3, GI50=0.33), prostate (PC-3, GI50=0.56), and breast cancer (MCF7, GI50=0.52), leukemia (K-562, GI50=0.41; SR, GI50=0.29), and melanoma (MDA-MB-435, GI50=0.31; SK-MEL-5, GI50=0.74; UACC-62, GI50=0.32). SAR-analysis is also discussed. PMID:23833709

  8. Alkyl sulfonic acide hydrazides: Synthesis, characterization, computational studies and anticancer, antibacterial, anticarbonic anhydrase II (hCA II) activities

    NASA Astrophysics Data System (ADS)

    O. Ozdemir, Ummuhan; İlbiz, Firdevs; Balaban Gunduzalp, Ayla; Ozbek, Neslihan; Karagoz Genç, Zuhal; Hamurcu, Fatma; Tekin, Suat

    2015-11-01

    Methane sulfonic acide hydrazide, CH3SO2NHNH2 (1), ethane sulfonic acide hydrazide, CH3CH2SO2NHNH2 (2), propane sulfonic acide hydrazide, CH3CH2CH2SO2NHNH2 (3) and butane sulfonic acide hydrazide, CH3CH2CH2CH2SO2NHNH2 (4) have been synthesized as homologous series and characterized by using elemental analysis, spectrophotometric methods (1H-13C NMR, FT-IR, LC-MS). In order to gain insight into the structure of the compounds, we have performed computational studies by using 6-311G(d, p) functional in which B3LYP functional were implemented. The geometry of the sulfonic acide hydrazides were optimized at the DFT method with Gaussian 09 program package. A conformational analysis of compounds were performed by using NMR theoretical calculations with DFT/B3LYP/6-311++G(2d, 2p) level of theory by applying the (GIAO) approach. The anticancer activities of these compounds on MCF-7 human breast cancer cell line investigated by comparing IC50 values. The antibacterial activities of synthesized compounds were studied against Gram positive bacteria; Staphylococcus aureus ATCC 6538, Bacillus subtilis ATCC 6633, Bacillus cereus NRRL-B-3711, Enterococcus faecalis ATCC 29212 and Gram negative bacteria; Escherichia coli ATCC 11230, Pseudomonas aeruginosa ATCC 15442, Klebsiella pneumonia ATCC 70063 by using the disc diffusion method. The inhibition activities of these compounds on carbonic anhydrase II enzyme (hCA II) have been investigated by comparing IC50 and Ki values. The biological activity screening shows that butane sulfonic acide hydrazide (4) has more activity than the others against tested breast cancer cell lines MCF-7, Gram negative/Gram positive bacteria and carbonic anhydrase II (hCA II) isoenzyme.

  9. Preparation and characterization of high performance sulfonated poly(p-phenylene-co-aryl ether ketone) membranes for direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    He, Qingyi; Zheng, Jifu; Zhang, Suobo

    2014-08-01

    A series of sulfonated poly(p-phenylene-co-aryl ether ketone)s (SPP-co-PAEK) have been designed as membrane materials for direct methanol fuel cell (DMFC) applications. The materials for such membranes have been prepared via the nickel (0) catalyzed coupling copolymerization of 2,5-dichloro-3-sulfobenzophenone and 2,6-bis(4-(4-chlorobenzoyl)phenoxy)benzonitrile. The SPP-co-PAEK membranes show the desired characteristics such as excellent thermal and mechanical properties, good oxidative stability, low methanol permeability and well-defined micro-phase separation. With an ion exchange capacity (IEC) ranging from 1.90 to 2.59 mequiv g-1, these membranes display comparable proton conductivity (0.085-0.170 S cm-1) to Nafion@117 when fully hydrated at 80 °C. In addition, the passive direct methanol fuel cell with SPP-co-PAEK CN 1.86 (IEC = 1.90 mequiv g-1) membrane presents a maximum power density of 24.5 mW cm-2 at 25 °C, which is comparable to the value of Nafion@117 (24.3 mW cm-2).

  10. N-Alkyl/aryl-4-(3-substituted-3-phenylpropyl)piperazine-1-carbothioamide as dual-action vaginal microbicides with reverse transcriptase inhibition.

    PubMed

    Bala, Veenu; Mandalapu, Dhanaraju; Gupta, Sonal; Jangir, Santosh; Kushwaha, Bhavana; Chhonker, Yashpal S; Chandasana, Hardik; Krishna, Shagun; Rawat, Kavita; Krishna, Atul; Singh, Mala; Sankhwar, Satya N; Shukla, Praveen K; Maikhuri, Jagdamba P; Bhatta, Rabi S; Siddiqi, Mohammad I; Tripathi, Rajkamal; Gupta, Gopal; Sharma, Vishnu L

    2015-08-28

    The growing population and health-care burden (due to STIs and HIV) imposes a particular economic crisis over resource-poor countries. Thus a novel approach as vaginal microbicides emerges as integrated tool to control both population and anti-STIs/HIV. Our continued efforts in this field led to the synthesis of fifteen N-alkyl/aryl-4-(3-substituted-3-phenylpropyl) piperazine-1-carbothioamide (12-26) derivatives as topical vaginal microbicides which were evaluated for anti-Trichomonas, spermicidal, antifungal and reverse transcriptase (RT) inhibitory activities. All compounds were also tested for preliminary safety through cytotoxicity assays against human cervical cell line (HeLa) and the vaginal flora, Lactobacillus. Docking studies were performed to gain an insight into the binding mode and interactions of the most promising compound 12 [oxo derivative], comprising of reverse transcriptase (RT) inhibitory (72.30%), spermicidal (MEC 0.01%), anti-Trichomonas (MIC 46.72 μM) and antifungal (MIC 9.34-74.8 μM) activities, along with its hydroxyl (17) and O-alkylated 4-trifluoromethylphenoxy (22) derivative, with similar activities. The stability of compound 12 in simulated vaginal fluid (SVF) and its preliminary in vivo pharmacokinetics performed in female NZ-rabbits signifies its clinical safety in comparison to marketed spermicide Nonoxynol-9. PMID:26209833

  11. Direct Preparation of 3-Iodochromenes from 3-Aryl- and 3-Alkyl-2-propyn-1-ols with Diaryliodonium Salts and NIS.

    PubMed

    Sasaki, Teppei; Miyagi, Kotaro; Moriyama, Katsuhiko; Togo, Hideo

    2016-03-01

    On the basis of a study of the O-phenylation of 3-phenyl-2-propyn-1-ol with diphenyliodonium triflate and t-BuONa, a variety of 4-aryl-3-iodo-2H-benzopyrans were prepared in good to moderate yields in one pot from the reaction of 3-aryl-2-propyn-1-ols with diaryliodonium triflates and t-BuONa, followed by the treatment with N-iodosuccinimide and BF3·OEt2, under transition-metal-free and mild conditions. The formed 4-phenyl-3-iodo-2H-benzopyran was converted into 4-phenyl-2H-benzopyran derivatives through C-C bond formations at the 3-position by Pd-catalyzed coupling reactions and into coumarin with oxidants. PMID:26886081

  12. Direct Olefination of Alcohols with Sulfones by Using Heterogeneous Platinum Catalysts.

    PubMed

    Siddiki, S M A Hakim; Touchy, Abeda Sultana; Kon, Kenichi; Shimizu, Ken-Ichi

    2016-04-18

    Carbon-supported Pt nanoparticles (Pt/C) were found to be effective heterogeneous catalysts for the direct Julia olefination of alcohols in the presence of sulfones and KOtBu under oxidant-free conditions. Primary alcohols, including aryl, aliphatic, allyl, and heterocyclic alcohols, underwent olefination with dimethyl sulfone and aryl alkyl sulfones to give terminal and internal olefins, respectively. Secondary alcohols underwent methylenation with dimethyl sulfone. Under 2.5 bar H2, the same reaction system was effective for the transformation of alcohol OH groups to alkyl groups. Structural and mechanistic studies of the terminal olefination system suggested that Pt(0) sites on the Pt metal particles are responsible for the rate-limiting dehydrogenation of alcohols and that KOtBu may deprotonate the sulfone reagent. The Pt/C catalyst was reusable after the olefination, and this method showed a higher turnover number (TON) and a wider substrate scope than previously reported methods, which demonstrates the high catalytic efficiency of the present method. PMID:26928740

  13. Crystal structures of five 1-alkyl-4-aryl-1,2,4-triazol-1-ium halide salts.

    PubMed

    Guino-O, Marites A; Talbot, Meghan O; Slitts, Michael M; Pham, Theresa N; Audi, Maya C; Janzen, Daron E

    2015-06-01

    The asymmetric units for the salts 4-(4-fluoro-phen-yl)-1-isopropyl-1,2,4-triazol-1-ium iodide, C11H13FN3 (+)·I(-), (1), 1-isopropyl-4-(4-methyl-phen-yl)-1,2,4-triazol-1-ium iodide, C12H16N3 (+)·I(-), (2), 1-isopropyl-4-phenyl-1,2,4-triazol-1-ium iodide, C11H14N3 (+)·I(-), (3), and 1-methyl-4-phenyl-1,2,4-triazol-1-ium iodide, C9H10N3 (+)·I(-), (4), contain one cation and one iodide ion, whereas in 1-benzyl-4-phenyl-1,2,4-triazol-1-ium bromide monohydrate, C15H14N3 (+)·Br(-)·H2O, (5), there is an additional single water mol-ecule. There is a predominant C-H⋯X(halide) inter-action for all salts, resulting in a two-dimensional extended sheet network between the triazolium cation and the halide ions. For salts with para-substitution on the aryl ring, there is an additional π-anion inter-action between a triazolium carbon and iodide displayed by the layers. For salts without the para-substitution on the aryl ring, the π-π inter-actions are between the triazolium and aryl rings. The melting points of these salts agree with the predicted substituent inductive effects. PMID:26090137

  14. Crystal structures of five 1-alkyl-4-aryl-1,2,4-triazol-1-ium halide salts

    PubMed Central

    Guino-o, Marites A.; Talbot, Meghan O.; Slitts, Michael M.; Pham, Theresa N.; Audi, Maya C.; Janzen, Daron E.

    2015-01-01

    The asymmetric units for the salts 4-(4-fluoro­phen­yl)-1-isopropyl-1,2,4-triazol-1-ium iodide, C11H13FN3 +·I−, (1), 1-isopropyl-4-(4-methyl­phen­yl)-1,2,4-triazol-1-ium iodide, C12H16N3 +·I−, (2), 1-isopropyl-4-phenyl-1,2,4-triazol-1-ium iodide, C11H14N3 +·I−, (3), and 1-methyl-4-phenyl-1,2,4-triazol-1-ium iodide, C9H10N3 +·I−, (4), contain one cation and one iodide ion, whereas in 1-benzyl-4-phenyl-1,2,4-triazol-1-ium bromide monohydrate, C15H14N3 +·Br−·H2O, (5), there is an additional single water mol­ecule. There is a predominant C—H⋯X(halide) inter­action for all salts, resulting in a two-dimensional extended sheet network between the triazolium cation and the halide ions. For salts with para-substitution on the aryl ring, there is an additional π–anion inter­action between a triazolium carbon and iodide displayed by the layers. For salts without the para-substitution on the aryl ring, the π–π inter­actions are between the triazolium and aryl rings. The melting points of these salts agree with the predicted substituent inductive effects. PMID:26090137

  15. Chemoselectivity in the Cu-catalyzed O-arylation of phenols and aliphatic alcohols.

    PubMed

    Maiti, Debabrata

    2011-08-01

    An orthogonal set of Cu-catalysts for the selective mono-arylation of alkyl aryl diols using aryl iodides is presented. Picolinic acid ligated copper catalyst provided phenol O-arylation only, while alkyl aryl ethers are generated by ligand-free copper catalyst in the presence of 2 equivalents NaOt-Bu. PMID:21698330

  16. Electrografting of alkyl films at low driving force by diverting the reactivity of aryl radicals derived from diazonium salts.

    PubMed

    Hetemi, Dardan; Kanoufi, Frédéric; Combellas, Catherine; Pinson, Jean; Podvorica, Fetah I

    2014-11-25

    Alkyl and partial perfluoroalkyl groups are strongly attached to carbon surfaces through (i) the abstraction of the iodine atom from an iodoalkane by the sterically hindered 2,6-dimethylphenyl radical and (ii) the reaction of the ensuing alkyl radical with the carbon surface. Since the 2,6-dimethylphenyl radical is obtained at -0.25 V/Ag/AgCl by reducing the corresponding diazonium salt, the electrografting reaction is facilitated by ∼1.7 V by comparison with the direct electrografting of the iodo compounds. Layers of various thicknesses, including monolayers, are obtained by controlling the time duration of the electrolysis. The grafted films are characterized by electrochemistry, IR, XPS, ellipsometry, and water contact angles. PMID:25350951

  17. Biogeochemical dynamics of perfluorinated alkyl acids and sulfonates in the River Seine (Paris, France) under contrasting hydrological conditions.

    PubMed

    Labadie, Pierre; Chevreuil, Marc

    2011-12-01

    The biogeochemical dynamics of 15 perfluorinated compounds (PFCs) were investigated in a heavily urbanised river (River Seine, Paris, France). The target compounds included C4-C10 sulfonates and C5-C14 acids; eleven PFCs were detected and ∑PFCs ranged between 31 and 91 ng L(-1) (median: 47 ng L(-1)). The molecular pattern was dominated by the perfluoroalkyl sulfonates PFHxS and PFOS (>54% of ∑PFCs), which were the only PFCs quantified in both the dissolved and particulate phases. For these PFCs, the sorbed fraction positively correlated with suspended sediment levels. Total PFC levels negatively correlated with river flow rate, which varied between 150 and 640 m(3) s(-1). This suggests the predominance of point sources (likely WWTP effluent discharge), but a contribution of non-point sources such as combined sewer overflow could not be excluded. The annual PFC mass flow was estimated at 500 kg, which is less than observed for other large European rivers. PMID:21899936

  18. Indolyl aryl sulfones as HIV-1 non-nucleoside reverse transcriptase inhibitors: role of two halogen atoms at the indole ring in developing new analogues with improved antiviral activity.

    PubMed

    Regina, Giuseppe La; Coluccia, Antonio; Piscitelli, Francesco; Bergamini, Alberto; Sinistro, Anna; Cavazza, Antonella; Maga, Giovanni; Samuele, Alberta; Zanoli, Samantha; Novellino, Ettore; Artico, Marino; Silvestri, Romano

    2007-10-01

    Indolyl aryl sulfones bearing the 4,5-difluoro (10) or 5-chloro-4-fluoro (16) substitution pattern at the indole ring were potent inhibitors of HIV-1 WT and the NNRTI-resistant strains Y181C and K103N-Y181C. These compounds were highly effective against the 112 and the AB1 strains in lymphocytes and inhibited at nanomolar concentration the multiplication of the IIIBBa-L strain in macrophages. Compound 16 was exceptionally potent against RT WT and RTs carrying the K103N, Y181I, and L100I mutations. PMID:17803291

  19. Synthesis and characterization of hexakis(alkyl isocyanide) and hexakis(aryl isocyanide) complexes of technetium(I)

    SciTech Connect

    Abrams, M.J.; Davison, A.; Jones, A.G.; Costello, C.E.; Pang, H.

    1983-09-28

    The complexes, hexakis(alkyl isocyanide) technetium(I) hexafluorophosphate (Tc(CNR)/sub 6/)PF/sub 6/ (where R = tert-butyl, methyl, cyclohexyl, and phenyl), have been prepared by reduction of the pertechnetate ion with aqueous sodium dithionite (Na/sub 2/S/sub 2/O/sub 4/) in the presence of the isocyanide ligands. These complexes have been characterized by elemental analysis, optical, ir, and /sup 1/H NMR spectroscopy, conductance, cyclic voltammetry, and field desorption mass spectrometry.

  20. 2 D - QSAR studies on CYP26A1 inhibitory activity of 1-[benzofuran-2-yl-(4-alkyl/aryl-phenyl)-methyl]- 1 H-triazoles.

    PubMed

    Yadav, Madhu

    2011-01-01

    The Quantitative Structure Activity Relationship (QSAR) study is performed over a set of 15, 4-alkyl/aryl-substituted 1- [benzofuran-2-yl-phenylmethyl]-1 H-triazoles derivatives. This study is based on the application of physicochemical parameters in QSAR. The parameters include (MR (molar refractivity), MW (molecular weight), Pc (parachor), St (surface tension), D (density), Ir (index of refraction) and log P (partition coefficient). The parameters describing physiochemical properties are used as independent variables and the biological activity (IC(50)) is considered as dependent variable in multiple regression analysis. Different models were generated with high co-efficient of determination (R(2)). The 2D-QSAR study identified compounds capable of inhibiting the metabolic breakdown of the retinoid (trans-retinoic acid (ATRA)) involved in the activation of specific nuclear Retinoic acid receptors (RARs). This study identifies R115866 as a potential inhibitor of the cytochrome P450 (CYP) mediated metabolism with increased RA levels for retinoid actions. PMID:22347780

  1. Design and synthesis of some new 1-phenyl-3/4-[4-(aryl/heteroaryl/alkyl-piperazine1-yl)-phenyl-ureas as potent anticonvulsant and antidepressant agents.

    PubMed

    Mishra, Chandra Bhushan; Kumari, Shikha; Tiwari, Manisha

    2016-05-01

    A series of 1-phenyl-3/4-[4-(aryl/heteroaryl/alkyl-piperazine1-yl)-phenyl-urea derivatives (29-42) were designed, synthesized and evaluated for their anticonvulsant activity by using maximal electroshock (MES), subcutaneous pentylenetetrazole (scPTZ) seizure tests. The acute neurotoxicity was checked by rotarod assay. Most of the test compounds were found effective in both seizure tests. Compound 30 (1-{4-[4-(4-chloro-phenyl)-piperazin-1-yl]-phenyl}-3-phenyl-urea) exhibited marked anticonvulsant activity in MES as well as scPTZ tests. The phase II anticonvulsant quantification study of compound 30 indicates the ED50 value of 28.5 mg/kg against MES induced seizures. In addition, this compound also showed considerable protection against pilocarpine induced status epilepticus in rats. Seizures induced by 3-mercaptopropionic acid model and thiosemicarbazide were significantly attenuated by compound 30, which suggested its broad spectrum of anticonvulsant activity. Interestingly, compound 30 displayed better antidepressant activity than standard drug fluoxetine. Moreover, compound 30 appeared as a non-toxic chemical entity in sub-acute toxicity studies. PMID:26891908

  2. Design, synthesis and pharmacological evaluation of N-[4-(4-(alkyl/aryl/heteroaryl)-piperazin-1-yl)-phenyl]-carbamic acid ethyl ester derivatives as novel anticonvulsant agents.

    PubMed

    Kumari, Shikha; Mishra, Chandra Bhushan; Tiwari, Manisha

    2015-03-01

    A series of alkyl/aryl/heteroaryl piperazine derivatives (37-54) were designed and synthesized as potential anticonvulsant agents. The target compounds are endowed with satisfactory physicochemical as well as pharmacokinetic properties. The synthesized compounds were screened for their in vivo anticonvulsant activity in maximal electroshock (MES) and subcutaneous pentylenetetrazole (sc-PTZ) seizure tests. Further, neurotoxicity evaluation was carried out using rotarod method. Structure activity relationship studies showed that compounds possessing aromatic group at the piperazine ring displayed potent anticonvulsant activity. Majority of the compounds showed anti-MES activity whereas compounds 39, 41, 42, 43, 44, 50, 52, and 53 exhibited anticonvulsant activity in both seizure tests. All the compounds except 42, 46, 47, and 50 did not show neurotoxicity. The most active derivative, 45 demonstrated potent anticonvulsant activity in MES test at the dose of 30mg/kg (0.5h) and 100mg/kg (4h) and also delivered excellent protection in sc-PTZ test (100mg/kg) at both time intervals. Therefore, compound 45 was further assessed in PTZ-kindling model of epilepsy which is widely used model for studying epileptogenesis. This compound was effective in delaying onset of PTZ-evoked seizures at the dose of 5mg/kg in kindled animals and significantly reduced oxidative stress better than standard drug phenobarbital (PB). In result, compound 45 emerged as a most potent and safer anticonvulsant lead molecule. PMID:25619635

  3. Side-chain-to-tail cyclization of ribosomally derived peptides promoted by aryl and alkyl amino-functionalized unnatural amino acids.

    PubMed

    Frost, John R; Wu, Zhijie; Lam, Yick Chong; Owens, Andrew E; Fasan, Rudi

    2016-06-28

    A strategy for the production of side-chain-to-tail cyclic peptides from ribosomally derived polypeptide precursors is reported. Two genetically encodable unnatural amino acids, bearing either an aryl or alkyl amino group, were investigated for their efficiency toward promoting the formation of medium to large-sized peptide macrocycles via intein-mediated side-chain-to-C-terminus cyclization. While only partial cyclization was observed with precursor proteins containing para-amino-phenylalanine, efficient peptide macrocyclization could be achieved using O-2-aminoethyl-tyrosine as the reactive moiety. Conveniently, the latter was generated upon quantitative, post-translational reduction of the azido-containing counterpart, O-2-azidoethyl-tyrosine, directly in E. coli cells. This methodology could be successfully applied for the production of a 12 mer cyclic peptide with enhanced binding affinity for the model target protein streptavidin as compared to the acyclic counterpart (KD: 5.1 μM vs. 22.4 μM), thus demonstrating its utility toward the creation and investigation of novel, functional macrocyclic peptides. PMID:27064594

  4. Use of dynamic simulation to assess the behaviour of linear alkyl benzene sulfonates and their biodegradation intermediates (sulfophenylcarboxylic acids) in estuaries

    NASA Astrophysics Data System (ADS)

    García-Luque, E.; González-Mazo, E.; Forja, J. M.; Gómez-Parra, A.

    2009-02-01

    Dynamic laboratory simulation of processes affecting chemical species in their transit through estuaries is a very useful tool to characterize these littoral systems. To date, laboratory studies concerning biodegradation and sorption (onto suspended particulate matter) of LAS in an estuary are scarce. For this reason, a dynamic automated estuarine simulator has been employed to carry out different experiments in order to assess the biodegradability of linear alkyl benzene sulfonates (LAS) and their biodegradation intermediates (sulfophenylcarboxylic acids, SPCs) using environmentally representative LAS concentrations in estuaries by a continuous injection of LAS into the system. During the experiments, a great affinity of LAS for the solid phase has been found, as well as an increased adsorption in line with increased chain length. On the other hand, the presence of SPCs with chain length between 6 and 13 carbon atoms was detected. Accumulation and persistence of medium chain length SPCs (C 6-C 8) along the experiments show that their degradation constitutes the limiting step for the process of LAS mineralization. In the final zone of the simulated estuarine system, the levels of SPCs were below the limits of detection. Thus, the disappearance of SPCs indicated that LAS biodegradation had been completed along the estuary. Similar results have been described for different Iberian littoral ecosystems. Therefore, the simulator employed in this research appears to be a useful tool to anticipate the behaviour of a xenobiotic chemical in its transit through littoral systems with different salinity gradients.

  5. Study of adjuvant effect of model surfactants from the groups of alkyl sulfates, alkylbenzene sulfonates, alcohol ethoxylates and soaps.

    PubMed

    Clausen, S K; Sobhani, S; Poulsen, O M; Poulsen, L K; Nielsen, G D

    2000-11-01

    The sodium salts of representatives of anionic surfactants, dodecylbenzene sulfonate (SDBS), dodecyl sulfate (SDS) and coconut oil fatty acids, and a nonionic surfactant, dodecyl alcohol ethoxylate, were studied for adjuvant effect on the production of specific IgE antibodies in mice. The surfactants were injected subcutaneously (sc) in concentrations of 1000, 100, 10 or 1 mg/l, respectively, together with 1 microg of ovalbumin (OVA). In addition, groups of mice received OVA in saline (control group) or in Al(OH)(3) (positive adjuvant control group). After the primary immunization the mice were boosted up to three times with OVA (0.1 microg sc) in saline. OVA-specific IgE antibodies were determined by the heterologous mouse rat passive cutaneous anaphylaxis test. The results were confirmed by a specific ELISA method. After the first booster, the Al(OH)(3) group and the 10 mg/l SDS group showed a statistically significant increase in OVA specific IgE levels. After two boosters, a statistically significant suppression in OVA-specific IgE production occurred with SDS (1000 mg/l), SDBS (1000 and 100 mg/l), coconut soap (1000 mg/l) and the alcohol ethoxylate (10 mg/l). This study suggests that a limited number of surfactants possess an adjuvant effect whereas all surfactants at certain levels can suppress specific IgE production. PMID:11038243

  6. Double-addition reaction of aryl methyl sulfones with N-tert-butylsulfinyl imines: diastereoselective and concise synthesis of 2-sulfonylated 1,3-diamines.

    PubMed

    Li, Ya; Li, Desheng; Zheng, Tao; Li, Hongsen; Ren, Xinfeng

    2014-11-10

    We report a double-addition reaction of methyl phenyl sulfone and methyl 2-pyridyl sulfone with N-tert-butylsulfinyl imines. This method provides concise access to 2-sulfonylated 1,3-anti diamines with good to excellent diastereoselectivities. This protocol has the benefit of using readily accessible starting materials and is operationally simple. PMID:25288374

  7. Ligand-Mediated and Copper-Catalyzed C(sp3)-H Bond Functionalization of Aryl Ketones with Sodium Sulfinates under Mild Conditions

    NASA Astrophysics Data System (ADS)

    Lan, Xing-Wang; Wang, Nai-Xing; Bai, Cui-Bing; Zhang, Wei; Xing, Yalan; Wen, Jia-Long; Wang, Yan-Jing; Li, Yi-He

    2015-12-01

    A novel and convenient copper (II) bromide and 1,8-diazabicyclo[5.4.1]undec-7-ene (DBU) or 1,10-phenanthroline catalysis protocol for the construction of α-alkyl-β-keto sulfones via C(sp3)-H bond functionalization followed by C(sp3)-S bond formation between aryl ketones and sodium sulfinates at room temperature has been developed. This method is applicable to a wide range of aryl ketones and sodium sulfinates. The electronic effects of aryl ketones and ligands effects of the copper salts are crucial for this transformation. Typically, substituted aryl ketones with electron-withdrawing group do not need any ligand to give a good to excellent yield, while substituted aryl ketones with electron-donating group and electron-rich heteroaromatic ketones offer a good to excellent yield only under the nitrogen-based ligands. The practical value of this transformation highlights the efficient and robust one-pot synthesis of α-alkyl-β-keto sulfones.

  8. Ligand-Mediated and Copper-Catalyzed C(sp3)-H Bond Functionalization of Aryl Ketones with Sodium Sulfinates under Mild Conditions

    PubMed Central

    Lan, Xing-Wang; Wang, Nai-Xing; Bai, Cui-Bing; Zhang, Wei; Xing, Yalan; Wen, Jia-Long; Wang, Yan-Jing; Li, Yi-He

    2015-01-01

    A novel and convenient copper (II) bromide and 1,8-diazabicyclo[5.4.1]undec-7-ene (DBU) or 1,10-phenanthroline catalysis protocol for the construction of α-alkyl-β-keto sulfones via C(sp3)-H bond functionalization followed by C(sp3)-S bond formation between aryl ketones and sodium sulfinates at room temperature has been developed. This method is applicable to a wide range of aryl ketones and sodium sulfinates. The electronic effects of aryl ketones and ligands effects of the copper salts are crucial for this transformation. Typically, substituted aryl ketones with electron-withdrawing group do not need any ligand to give a good to excellent yield, while substituted aryl ketones with electron-donating group and electron-rich heteroaromatic ketones offer a good to excellent yield only under the nitrogen-based ligands. The practical value of this transformation highlights the efficient and robust one-pot synthesis of α-alkyl-β-keto sulfones. PMID:26681470

  9. Nucleophilic reactions at a Vinylic Center. XVII. formation of derivatives of 1,3,4-thiadiazole and 1,3,4-oxadiazole in the reaction of 2,2-dichlorovinyl Sulfones with thiosemicarbazide and Semicarbazide

    SciTech Connect

    Shainyan, B.A.; Indyukova, L.N.; Kalikmann, I.D.; Mirskova, A.N.

    1986-08-01

    The reaction of 2,2-dichlorovinyl sulfones with thiosemicarbazide and semicarbazide, leading to the formation of 2-alkyl(aryl)sulfonylmethyl-5-amino-1,3,4-thiadiazoles and 2-alkyl(aryl)sulfonylmethyl-5-amino-1,3,4-oxadiazoles respectively, was investigated. In contrast, the reactions of sulfonylacetic esters with thiosemicarbazide and semicarbazide lead to the formation of 3-sulfonyl-methyl-5-mercapto-1,2,4-triazoles and 3-sulfonylmethyl-5-hydroxy-1,2,4-triazoles respectively. The derivatives of 1,3,4-thiadiazole and 1,3,4-oxadiazole are formed from the 2,2-dichlorovinyl sulfones by substitution of the two chlorine atoms with subsequent cyclization of the intermediately formed salts.

  10. General and modular synthesis of isomeric 5-substituted pyridin-2-yl and 6-substituted pyridin-3-yl C-ribonucleosides bearing diverse alkyl, aryl, hetaryl, amino, carbamoyl, and hydroxy groups.

    PubMed

    Štefko, Martin; Slavětínská, Lenka; Klepetářová, Blanka; Hocek, Michal

    2011-08-19

    A general modular and practical methodology for preparation of diverse 5-substituted pyridin-2-yl and 6-substituted pyridin-3-yl C-ribonucleosides was developed. Regioselective lithiation of 2,5-dibromopyridine proceeded at position 5 or 2 depending on the solvent, and the resulting bromopyridyl lithium species underwent additions to TBS-protected ribonolactone and follow-up transformations to corresponding acetylated hemiketal intermediates 7 and 10 that were diastereoselectively reduced to give either 5-bromopyridin-2-yl or 6-bromopyridin-3-yl silyl-protected C-ribonucleosides 8 or 11 in 68% and 77% overall yields as pure β-anomers. These bromopyridyl C-nucleoside intermediates were then subjected to a series of palladium-catalyzed cross-coupling reactions, aminations, aminocarbonylations, and hydroxylations to give a series of protected 1β-(5-alkyl-, 5-aryl-, 5-amino-, 5-carbamoyl-, and 5-hydroxypyridin-2-yl)-C-ribonucleosides 13a-i and β-(6-alkyl-, 6-aryl-, 6-amino-, 6-carbamoyl-, and 6-hydroxypyridin-3-yl)-C-ribonucleosides 15a-i. Deprotection of silylated nucleosides by Et(3)N·3HF, TBAF, or TFA gave a series of free C-nucleosides 14a-i and 16a-i. PMID:21739971

  11. A Mild Synthesis of New Aryl Vinyl Ethers and Diethyl 1-[(Alkyl)(cyano)methyl]vinylphosphonates via the Substitution of a 2,3-Difunctional Allyl Bromide

    PubMed Central

    Ben Kraïem, Jihène; Arfaoui, Aïcha; Amri, Hassen

    2014-01-01

    A novel class of aryl vinyl ethers 3 and diethyl 3-cyano-3-alkylprop-1-en-2-ylphosphonates 4 has been prepared, respectively, from coupling reaction of diethyl 1-(bromomethyl)-2-cyanovinylphosphonate 2 with phenols and Gilman reagents. PMID:24688373

  12. Enantioselective Synthesis of Homoallylic Amines through Reactions of (Pinacolato)allylborons with Aryl-, Heteroaryl-, Alkyl- or Alkene-Substituted Aldimines Catalyzed by Chiral C1-Symmetric NHC–Cu Complexes

    PubMed Central

    Vieira, Erika M.; Snapper, Marc L.; Hoveyda, Amir H.

    2011-01-01

    A catalytic method for enantioselective synthesis of homoallylamides through Cu-catalyzed reactions of stable and easily accessible (pinacolato)allylborons with aryl-, heteroaryl-,alkyl- or alkenyl-substituted N-phosphinoylimines is disclosed. Transformations are promoted by 1–5 mol % of readily accessible NHC–Cu complexes, derived from C1-symmetric imidazolinium salts, which can be prepared in multi-gram quantities in four steps from commercially available materials. Allyl additions deliver the desired products in up to quantitative yield and 98.5:1.5 enantiomeric ratio and are amenable to gram-scale operations. A mechanistic model accounting for the observed selectivity levels and trends is proposed. PMID:21341657

  13. Synthesis of β-arylated alkylamides via Pd-catalyzed one-pot installation of a directing group and C(sp3)–H arylation

    PubMed Central

    Zhang, Yi; Cao, Xiaoji; Wan, Jie-Ping

    2016-01-01

    Summary The synthesis of β-arylated alkylamides via alkyl C–H bond arylation has been realized by means of direct one-pot reactions of acyl chlorides, aryl iodides and 8-aminoquinoline. Depending on the structure of the starting materials, both single and double β-arylated alkylamides could be accessed. PMID:27340500

  14. High Potency of Indolyl Aryl Sulfone Nonnucleoside Inhibitors towards Drug-Resistant Human Immunodeficiency Virus Type 1 Reverse Transcriptase Mutants Is Due to Selective Targeting of Different Mechanistic Forms of the Enzyme

    PubMed Central

    Cancio, Reynel; Silvestri, Romano; Ragno, Rino; Artico, Marino; De Martino, Gabriella; La Regina, Giuseppe; Crespan, Emmanuele; Zanoli, Samantha; Hübscher, Ulrich; Spadari, Silvio; Maga, Giovanni

    2005-01-01

    Indolyl aryl sulfone (IAS) nonnucleoside inhibitors have been shown to potently inhibit the growth of wild-type and drug-resistant human immunodeficiency virus type 1 (HIV-1), but their exact mechanism of action has not been elucidated yet. Here, we describe the mechanism of inhibition of HIV-1 reverse transcriptase (RT) by selected IAS derivatives. Our results showed that, depending on the substitutions introduced in the IAS common pharmacophore, these compounds can be made selective for different enzyme-substrate complexes. Moreover, we showed that the molecular basis for this selectivity was a different association rate of the drug to a particular enzymatic form along the reaction pathway. By comparing the activities of the different compounds against wild-type RT and the nonnucleoside reverse transcriptase inhibitor-resistant mutant Lys103Asn, it was possible to hypothesize, on the basis of their mechanism of action, a rationale for the design of drugs which could overcome the steric barrier imposed by the Lys103Asn mutation. PMID:16251294

  15. Efficient and versatile catalysis of N-alkylation of heterocyclic amines with alcohols and one-pot synthesis of 2-aryl substituted benzazoles with newly designed ruthenium(II) complexes of PNS thiosemicarbazones.

    PubMed

    Ramachandran, Rangasamy; Prakash, Govindan; Selvamurugan, Sellappan; Viswanathamurthi, Periasamy; Malecki, Jan Grzegorz; Ramkumar, Venkatachalam

    2014-06-01

    Ruthenium(II) carbonyl complexes with phosphine-functionalized PNS type thiosemicarbazone ligands [RuCl(CO)(EPh3)(L)] (1-6) (E = P or As, L = 2-(2-(diphenylphosphino)benzylidene) thiosemicarbazone (PNS-H), 2-(2-(diphenylphosphino)benzylidene)-N-methylthiosemicarbazone (PNS-Me), 2-(2-(diphenylphosphino)benzylidene)-N-phenylthiosemicarbazone (PNS-Ph)) have been synthesized and characterized by elemental analysis and spectroscopy (IR, UV-Vis, (1)H, (13)C, (31)P-NMR) as well as ESI mass spectrometry. The molecular structures of complexes 1, 2 and 6 were identified by means of single-crystal X-ray diffraction analysis. The analysis revealed that all the complexes possess a distorted octahedral geometry with the ligand coordinating in a uni-negative tridentate PNS fashion. All the ruthenium complexes (1-6) were tested as catalyst for N-alkylation of heteroaromatic amines with alcohols. Notably, complex 2 was found to be a very efficient and versatile catalyst towards N-alkylation of a wide range of heterocyclic amines with alcohols. Complex 2 can also catalyze the direct amination of 2-nitropyridine with benzyl alcohol to the corresponding secondary amine. Furthermore, a preliminary examination of performance for N,N-dialkylation of diamine showed promising results, giving good conversion and high selectivity. In addition, N-alkylation of ortho-substituted anilines (-NH2, -OH and -SH) led to the one-pot synthesis of 2-aryl substituted benzimidazoles, benzoxazoles and benzothiazoles, also revealing the catalytic activity of complex 2. PMID:24705796

  16. 1H, 13C, 195Pt and 15N NMR structural correlations in Pd(II) and Pt(II) chloride complexes with various alkyl and aryl derivatives of 2,2'-bipyridine and 1,10-phenanthroline.

    PubMed

    Pawlak, Tomasz; Pazderski, Leszek; Sitkowski, Jerzy; Kozerski, Lech; Szłyk, Edward

    2011-02-01

    (1)H, (13)C, (195)Pt and (15)N NMR studies of platinide(II) (M = Pd, Pt) chloride complexes with such alkyl and aryl derivatives of 2,2'-bipyridine and 1,10-phenanthroline as LL = 6,6'-dimethyl-bpy, 5,5'-dimethyl-bpy, 4,4'-di-tert-butyl-bpy, 2,9-dimethyl-phen, 2,9-dimethyl-4,7-diphenyl-phen, 3,4,7,8-tetramethyl-phen, having the general [M(LL)Cl(2)] formula were performed and the respective chemical shifts (δ(1H), δ(13C), δ(195Pt), δ(15N)) reported. (1)H high-frequency coordination shifts (Δ(coord)(1H) = δ(complex)(1H)-δ(ligand)(1H)) mostly pronounced for nitrogen-adjacent protons and methyl groups in the nearest adjacency of nitrogen, as well as (15)N low-frequency coordination shifts (Δ(coord)(15H) = δ(complex)(15H)-δ(ligand)(15H)) were discussed in relation to the molecular structures. PMID:21254225

  17. One-pot, three-component arylalkynyl sulfone synthesis.

    PubMed

    Chen, C Chun; Waser, Jerome

    2015-02-01

    A one-pot three-component protocol for the preparation of arylsulfonyl alkynes through the reaction of ethynyl-benziodoxolone (EBX) reagents, DABSO (DABCO·SO2), and either organomagnesium reagents or aryl iodides with a palladium catalyst is reported. A broad range of aryl and heteroarylalkynyl sulfones were obtained in 46-85% overall yield. PMID:25633719

  18. Design, synthesis and biological evaluation of N-alkyl or aryl substituted isoindigo derivatives as potential dual cyclin-dependent kinase 2 (CDK2)/glycogen synthase kinase 3β (GSK-3β) phosphorylation inhibitors.

    PubMed

    Zhao, Ping; Li, Yanzhong; Gao, Guangwei; Wang, Shuai; Yan, Yun; Zhan, Xiaoping; Liu, Zenglu; Mao, Zhenmin; Chen, Shaoxiong; Wang, Liqun

    2014-10-30

    A series of N-alkyl or aryl substituted isoindigo derivatives have been synthesized and their anti-proliferative activity was evaluated by Sulforhodamine B (SRB) assay. Some of the target compounds exhibited significant antitumor activity, including compounds 6h and 6k (against K562 cells), 6i (against HeLa cells) and 6j (against A549 cells). N-(p-methoxy-phenyl)-isoindigo (6k) exhibited a high and selective anti-proliferative activity against K562 cells (IC50 7.8 μM) and induced the apoptosis of K562 cells in a dose-dependent manner. Compound 6k arrested the cell cycle at S phase in K562 cells by decreasing the expression of cyclin A and CDK2, which played critical roles in DNA replication and passage through G2 phase. Moreover, compound 6k down-regulated the expression of p-GSK-3β (Ser9), β-catenin and c-myc proteins, up-regulated the expression of GSK-3β, consequently, suppressed Wnt/β-catenin signaling pathway and induced the apoptosis of K562 cells. The binding mode of compound 6k with GSK-3β was simulated using molecular docking tools. All of these studies gave a better understanding to the molecular mechanisms of this class of agents and clues to develop dual CDK2/GSK-3β (Ser9) phosphorylation inhibitors applied in cancer chemotherapy. PMID:25151579

  19. Selective Pro-Apoptotic Activity of Novel 3,3′-(Aryl/Alkyl-Methylene)Bis(2-Hydroxynaphthalene-1,4-Dione) Derivatives on Human Cancer Cells via the Induction Reactive Oxygen Species

    PubMed Central

    Sinha, Krishnendu; Brahmachari, Goutam; Sil, Parames C.

    2016-01-01

    Selective induction of apoptosis in cancer cells barring the normal cells is considered as an effective strategy to combat cancer. In the present study, a series of twenty-two (22) synthetic 3,3'-(aryl/alkyl-methylene)bis(2-hydroxynaphthalene-1,4-dione) bis-lawsone derivatives were assayed for their pro-apoptotic activity in six different cell lines (five cancerous and one normal) using MTT assay. Out of these 22 test compounds, 1j was found to be the most effective in inducing apoptosis in human glioma cells (CCF-4) among the different cell lines used in the study. The activity of this compound, 1j, was then compared to a popular anticancer drug, cisplatin, having limited usage because of its nephrotoxic nature. In this study, 1j derivative showed much less toxicity to the normal kidney cells compared to cisplatin, thus indicating the superiority of 1j as a possible anticancer agent. This compound was observed to induce apoptosis in the glioma cells by inducing the caspase dependent apoptotic pathways via ROS and downregulating the PI3K/AKT/mTOR pathway. Estimation of different oxidative stress markers also confirms the induction of oxidative stress in 1j exposed cancer cells. The toxicity of 1j compound toward cancer cells was confirmed further by different flow cytometrical analyses to estimate the mitochondrial membrane potential and cell cycle. The sensitivity of malignant cells to apoptosis, provoked by this synthetic derivative in vitro, deserves further studies in suitable in vivo models. These studies not only identified a novel anticancer drug candidate but also help to understand the metabolism of ROS and its application in cancer treatment. PMID:27380262

  20. Estimated pKa values for the environmentally relevant C1 through C8 perfluorinated sulfonic acid isomers.

    PubMed

    Rayne, Sierra; Forest, Kaya

    2016-10-14

    In order to estimate isomer-specific acidity constants (pKa) for the perfluorinated sulfonic acid (PFSA) environmental contaminants, the parameterization method 6 (PM6) pKa prediction method was extensively validated against a wide range of carbon oxyacids and related sulfonic/sulfinic acids. Excellent pKa prediction performance was observed for the carbon oxyacids using the PM6 method, but this approach was found to have a severe positive bias for sulfonic/sulfinic acids. To overcome this obstacle, a correlation was developed between non-adjusted PM6 pKa values and the corresponding experimentally obtained/estimated acidity constants for a range of representative alkyl, aryl and halogen-substituted sulfonic acids. Application of this correction to the PM6 values allows for extension of this computational method to a new acid functional group. When used to estimate isomer-specific pKa values for the C1 through C8 PFSAs, the modified PM6 approach suggests an adjusted pKa range from -5.3 to -9.0, indicating that all members of this class of well-known environmental contaminants will be effectively completely dissociated in aquatic systems. PMID:27389973

  1. CuI/Oxalic Diamide Catalyzed Coupling Reaction of (Hetero)Aryl Chlorides and Amines.

    PubMed

    Zhou, Wei; Fan, Mengyang; Yin, Junli; Jiang, Yongwen; Ma, Dawei

    2015-09-23

    A class of oxalic diamides are found to be effective ligands for promoting CuI-catalyzed aryl amination with less reactive (hetero)aryl chlorides. The reaction proceeds at 120 °C with K3PO4 as the base in DMSO to afford a wide range of (hetero)aryl amines in good to excellent yields. The bis(N-aryl) substituted oxalamides are superior ligands to N-aryl-N'-alkyl substituted or bis(N-alkyl) substituted oxalamides. Both the electronic nature and the steric property of the aromatic rings in ligands are important for their efficiency. PMID:26352639

  2. Chan-Evans-Lam Amination of Boronic Acid Pinacol (BPin) Esters: Overcoming the Aryl Amine Problem.

    PubMed

    Vantourout, Julien C; Law, Robert P; Isidro-Llobet, Albert; Atkinson, Stephen J; Watson, Allan J B

    2016-05-01

    The Chan-Evans-Lam reaction is a valuable C-N bond forming process. However, aryl boronic acid pinacol (BPin) ester reagents can be difficult coupling partners that often deliver low yields, in particular in reactions with aryl amines. Herein, we report effective reaction conditions for the Chan-Evans-Lam amination of aryl BPin with alkyl and aryl amines. A mixed MeCN/EtOH solvent system was found to enable effective C-N bond formation using aryl amines while EtOH is not required for the coupling of alkyl amines. PMID:27045570

  3. Nano-CuFe2O4 as a magnetically separable and reusable catalyst for the synthesis of diaryl/aryl alkyl sulfides via cross-coupling process under ligand-free conditions.

    PubMed

    Swapna, Kokkirala; Murthy, Sabbavarapu Narayana; Jyothi, Mocharla Tarani; Nageswar, Yadavalli Venkata Durga

    2011-09-01

    An efficient protocol was developed for the CuFe(2)O(4) nanopowder-catalyzed aryl-sulfur bond formation between aryl halide and thiol/disulfide. A variety of aryl sulfides were synthesized in impressive yields with good chemoselectivity and functional group tolerance in the presence of a catalytic amount of CuFe(2)O(4), Cs(2)CO(3) as base, in nitrogen atmosphere, under ligand-free conditions, in DMSO as solvent at 100 °C. The catalyst is air-stable, inexpensive, magnetically separable and recyclable up to four cycles. PMID:21769376

  4. Aldicarb sulfone

    Integrated Risk Information System (IRIS)

    Aldicarb sulfone ; CASRN 1646 - 88 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  5. Efficient Synthesis of 3H-Indoles Enabled by the Lead-Mediated α-Arylation of β-Ketoesters or γ-Lactams Using Aryl Azides

    PubMed Central

    2015-01-01

    The development of a lead-mediated α-arylation reaction between aryl azides and β-ketoesters or γ-lactams that facilitates the formation of 3H-indoles is disclosed. Twenty-five examples are included which demonstrate the generality of this reaction to access aryl azides bearing tetrasubstituted o-alkyl substituents. When paired with a Staudinger reduction, this reaction streamlines the synthesis of functionalized 3H-indoles. PMID:24865180

  6. STILLE CROSS-COUPLING REACTIONS OF ARYL MESYLATES AND TOSYLATES USING A BIARYLPHOSPHINE BASED CATALYST SYSTEM‡

    PubMed Central

    Naber, John R.; Fors, Brett P.; Wu, Xiaoxing; Gunn, Jonathon

    2013-01-01

    A catalyst system for the Stille cross-coupling reactions of aryl mesylates and tosylates is reported. Using the combination of Pd(OAc)2, XPhos, and CsF in t-BuOH an array of aryl and heteroaryl sulfonates were successfully employed in these reactions. Morever, heteroarylstannanes, such as furyl, thiophenyl, and N-methylpyrrole, which are often prone to decomposition, were efficiently coupled under these conditions. Ortho-substitution on the stannane coupling partner was well tolerated; however, the presence of ortho substituents on the aryl sulfonates greatly reduced the proficiency of these reactions. PMID:23596345

  7. Sodium Polystyrene Sulfonate

    MedlinePlus

    ... allergic to sodium polystyrene sulfonate, other polystyrene sulfonate resins, any other medications, or any of the ingredients ... salt substitutes containing potassium or foods that are high in potassium.

  8. Preparation of sulfonic-functionalized graphene oxide as ion-exchange material and its application into electrochemiluminescence analysis.

    PubMed

    Chen, Guifen; Zhai, Shengyong; Zhai, Yanling; Zhang, Ke; Yue, Qiaoli; Wang, Lei; Zhao, Jinsheng; Wang, Huaisheng; Liu, Jifeng; Jia, Jianbo

    2011-03-15

    Graphene oxide (GO) obtained from chemical oxidation of flake graphite was derivatized with sulfonic groups to form sulfonic-functionalized GO (GO-SO(3)(-)) through four sulfonation routes: through amide formation between the carboxylic group of GO and amine of sulfanilic acid (AA-GO-SO(3)(-)), aryl diazonium reaction of sulfanilic acid (AD-GO-SO(3)(-)), amide formation between the carboxylic group of GO and amine of cysteamine and oxidation by H(2)O(2) (CA-GO-SO(3)(-)), and alkyl diazonium reaction of cysteamine and oxidation by H(2)O(2) (CD-GO-SO(3)(-)). Results of Fourier transform infrared spectroscopy and X-ray photoelectrospectrocopy showed that -SO(3)(-) groups were attached onto GO. Thermo gravimetric analysis showed that derivatization with sulfonic groups improved thermo stability of GO. X-ray diffraction results indicated that GO-SO(3)(-) had more ordered π-π stacking structure than the original GO. GO-SO(3)(-) and cationic polyelectrote, poly (diallyldimethylammoniumchloride) (PDDA) were adsorbed at indium tin oxide (ITO) glass surface through layer-by-layer assembling to form (GO-SO(3)(-)/PDDA)(n)/ITO multilayers. After tris-(2,2'-bipyridyl) ruthenium (II) dichloride (Ru(bpy)(3)(2+)) was incorporated into the multilayers, the obtained Ru(bpy)(3)(2+)/(GO-SO(3)(-)/PDDA)(n)/ITO electrodes can be used as electrochemiluminescence sensors for detection of organic amine with high sensitivity (limit of detection of 1 nM) and stability. PMID:21211958

  9. Copper-catalyzed arylation of biguanide derivatives via C-N cross-coupling reactions.

    PubMed

    Zhang, Chen; Huang, Bo; Bao, Ai-Qing; Li, Xiao; Guo, Shunna; Zhang, Jin-Quan; Xu, Jun-Zhi; Zhang, Rihao; Cui, Dong-Mei

    2015-12-21

    An efficient copper-catalyzed cross-coupling reaction of biguanide hydrochloride derivatives with both aryl iodides and bromides under mild conditions has been developed. The reaction occurred in good yields and tolerated aryl halides containing functionalities such as nitriles, sulfonamides, ethers, and halogens. Alkyl and cyclic substituted biguanidines were also well tolerated. PMID:26444146

  10. EFFECTS OF PRENATAL PERFLUOROOCTANE SULFONATE (PFOS) EXPOSURE ON LUNG MATURATION IN THE PERINATAL RAT

    EPA Science Inventory

    Background: Perfluorooctane sulfonate (PFOS), found widely in wildlife and humans, is environmentally and metabolically stable. Environmental PFOS may be from its use as a surfactant, hydrolysis of perfluorooctanesulfonyl fluoride, and degradation of N-alkyl-perfluorooctanesulfon...

  11. Lack of antagonism of 2,3,7,8-tetrachlorodibenzo-p-dioxin's (TCDDs) induction of cytochrome P4501A1 (CYP1A1) by the putative selective aryl hydrocarbon receptor modulator 6-alkyl-1,3,8-trichlorodibenzofuran (6-MCDF) in the mouse hepatoma cell line Hepa-1c1c7.

    PubMed

    Fretland, Adrian J; Safe, Stephen; Hankinson, Oliver

    2004-11-20

    Regulation of gene expression by the aryl hydrocarbon (AHR) receptor is a much-studied pathway of molecular toxicology. Activation of AHR by the xenobiotic ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is hypothesized as the mechanism by which TCDD exerts its toxic and carcinogenic effects. Paradoxically, some studies have shown that TCDD acts as an antiestrogen. This has led to the hypothesis that so-called selective aryl hydrocarbon receptor modulators (SAhRMs), AHR ligands that retain the antiestrogenic effects but lack the transcriptional effects of TCDD associated with toxicity, may be utilized as cancer chemotherapeutics in conjunction with other antiestrogenic compounds such as tamoxifen. The present study attempts to further define the molecular mechanism of action of the putative SAhRMs, 6-alkyl-1,3,8-trichlorodibenzofuran (6-MCDF), and diindolylmethane (DIM), focusing particularly on the former. We tested 6-MCDF and DIM for the recruitment of AHR and RNA polymerase II (pol II) to the regulatory region of the AHR responsive gene, cytochrome P4501A1 (CYP1A1), using the chromatin immunoprecipitation (ChIP) assay in the mouse hepatoma cell line Hepa-1c1c7 (Hepa-1). We also tested the level of CYP1A1 induction in Hepa-1 cells using quantitative real-time PCR. We show no difference in the recruitment of AHR or pol II to the regulatory region of CYP1A1 in response to TCDD, 6-MCDF, or co-treatment with both TCDD and 6-MCDF. Our results also show no antagonism of CYP1A1 induction with co-treatment of Hepa-1 cells with TCDD and 6-MCDF. These data suggest that 6-MCDF exhibits agonist activity with respect to induction of CYP1A1 in the Hepa-1 cell line. PMID:15535986

  12. High Lipophilicty of Perfluoroalkyl Carboxylate and Sulfonate

    PubMed Central

    Jing, Ping; Rodgers, Patrick J.; Amemiya, Shigeru

    2009-01-01

    Here we report on remarkably high lipophilicity of perfluoroalkyl carboxylate and sulfonate. A lipophilic nature of this emerging class of organic pollutants has been hypothesized as an origin of their bioaccumulation and toxicity. Both carboxylate and sulfonate, however, are considered hydrophilic while perfluroalkyl groups are not only hydrophobic but also oleophobic. Partition coefficients of homologous series of perfluoroalkyl and alkyl carboxylates between water and n-octanol were determined as a measure of their lipophilicity by ion-transfer cyclic voltammetry. Very similar lipophilicity of perfluoroalkyl and alkyl chains with the same length is demonstrated experimentally for the first time by fragment analysis of the partition coefficients. This finding is important for pharmaceutical and biomedical applications of perfluoroalkyl compounds. Interestingly, ∼2 orders of magnitude higher lipophilicity of a perfluoroalkyl carboxylate or sulfonate in comparison to its alkyl counterpart is ascribed nearly exclusively to their oxoanion groups. The higher lipophilicity originates from a strong electron-withdrawing effect of the perfluoroalkyl group on the adjacent oxoanion group, which is weakly hydrated to decrease its hydrophilicity. In fact, the inductive effect is dramatically reduced for a fluorotelomer with an ethylene spacer between perfluorohexyl and carboxylate groups, which is only as lipophilic as its alkyl counterpart, nonanoate, and is 400 times less lipophilic than perfluorononanoate. The high lipophilicity of perfluoroalkyl carboxylate and sulfonate implies that their permeation across such a thin lipophilic membrane as a bilayer lipid membrane is limited by their transfer at a membrane/water interface. The limiting permeability is lower and less dependent on their lipophilicity than the permeability controlled by their diffusion in the membrane interior as assumed in the classical solubility-diffusion model. PMID:19170492

  13. 15N NMR coordination shifts in Pd(II), Pt(II), Au(III), Co(III), Rh(III), Ir(III), Pd(IV), and Pt(IV) complexes with pyridine, 2,2'-bipyridine, 1,10-phenanthroline, quinoline, isoquinoline, 2,2'-biquinoline, 2,2':6', 2'-terpyridine and their alkyl or aryl derivatives.

    PubMed

    Pazderski, Leszek

    2008-01-01

    The 15N NMR data for 105 complexes of Pd(II), Pt(II), Au(III), Co(III), Rh(III), Ir(III), Pd(IV), and Pt(IV) complexes with simple azines such as pyridine, 2,2'-bipyridine, 1,10-phenanthroline, quinoline, isoquinoline, 2,2'-biquinoline, 2,2':6', 2''-terpyridine and their alkyl or aryl derivatives have been reviewed. The 15N NMR coordination shifts, i.e. the differences between the 15N chemical shifts of the same nitrogen in the molecules of the complex and the ligand (Delta(15N) (coord) = delta(15N) (compl)--delta(15N) (lig)), have been related to some structural features of the reviewed coordination compounds, like the type of the central ion and the character of auxiliary ligands (mainly in trans position). These Delta(15N) (coord) parameters are negative, their absolute magnitudes (ca 30-150 ppm) generally increasing in the metal order Au(III) < Pd(II) < Pt(II) and Rh(III) < Co(III) < Pt(IV) < Ir(III), as well as with the enhanced trans influence of the other donor atoms (H, C < Cl < N). PMID:18855335

  14. Amine synthesis via iron-catalysed reductive coupling of nitroarenes with alkyl halides.

    PubMed

    Cheung, Chi Wai; Hu, Xile

    2016-01-01

    (Hetero)Aryl amines, an important class of organic molecules in medicinal chemistry, are most commonly synthesized from anilines, which are in turn synthesized by hydrogenation of nitroarenes. Amine synthesis directly from nitroarenes is attractive due to improved step economy and functional group compatibility. Despite these potential advantages, there is yet no general method for the synthesis of (hetero)aryl amines by carbon-nitrogen cross-coupling of nitroarenes. Here we report the reductive coupling of nitroarenes with alkyl halides to yield (hetero)aryl amines. A simple iron catalyst enables the coupling with numerous primary, secondary and tertiary alkyl halides. Broad scope and high functional group tolerance are demonstrated. Mechanistic study suggests that nitrosoarenes and alkyl radicals are involved as intermediates. This new C-N coupling method provides general and step-economical access to aryl amines. PMID:27515391

  15. Amine synthesis via iron-catalysed reductive coupling of nitroarenes with alkyl halides

    PubMed Central

    Cheung, Chi Wai; Hu, Xile

    2016-01-01

    (Hetero)Aryl amines, an important class of organic molecules in medicinal chemistry, are most commonly synthesized from anilines, which are in turn synthesized by hydrogenation of nitroarenes. Amine synthesis directly from nitroarenes is attractive due to improved step economy and functional group compatibility. Despite these potential advantages, there is yet no general method for the synthesis of (hetero)aryl amines by carbon–nitrogen cross-coupling of nitroarenes. Here we report the reductive coupling of nitroarenes with alkyl halides to yield (hetero)aryl amines. A simple iron catalyst enables the coupling with numerous primary, secondary and tertiary alkyl halides. Broad scope and high functional group tolerance are demonstrated. Mechanistic study suggests that nitrosoarenes and alkyl radicals are involved as intermediates. This new C–N coupling method provides general and step-economical access to aryl amines. PMID:27515391

  16. Electric current-producing device having sulfone-based electrolyte

    DOEpatents

    Angell, Charles Austen; Sun, Xiao-Guang

    2010-11-16

    Electrolytic solvents and applications of such solvents including electric current-producing devices. For example, a solvent can include a sulfone compound of R1--SO2--R2, with R1 being an alkyl group and R2 a partially oxygenated alkyl group, to exhibit high chemical and thermal stability and high oxidation resistance. For another example, a battery can include, between an anode and a cathode, an electrolyte which includes ionic electrolyte salts and a non-aqueous electrolyte solvent which includes a non-symmetrical, non-cyclic sulfone. The sulfone has a formula of R1--SO2--R2, wherein R1 is a linear or branched alkyl or partially or fully fluorinated linear or branched alkyl group having 1 to 7 carbon atoms, and R2 is a linear or branched or partially or fully fluorinated linear or branched oxygen containing alkyl group having 1 to 7 carbon atoms. The electrolyte can include an electrolyte co-solvent and an electrolyte additive for protective layer formation.

  17. Copper-Catalyzed Reductive N-Alkylation of Amides with N-Tosylhydrazones Derived from Ketones.

    PubMed

    Xu, Peng; Qi, Fu-Ling; Han, Fu-She; Wang, Yan-Hua

    2016-07-20

    A CuI-catalyzed reductive coupling of ketone-derived N-tosylhydrazones with amides is presented. Under the optimized conditions, an array of N-tosylhydrazones derived from aryl-alkyl and diaryl ketones could couple effectively with a wide variety of (hetero)aryl as well as aliphatic amides to afford the N-alkylated amides in high yields. The method represents the very few examples for reliably accessing secondary and tertiary amides through a reductive N-alkylation protocol. PMID:27346856

  18. Enantioselective cross-coupling of meso-epoxides with aryl halides.

    PubMed

    Zhao, Yang; Weix, Daniel J

    2015-03-11

    The first enantioselective cross-electrophile coupling of aryl bromides with meso-epoxides to form trans-β-arylcycloalkanols is presented. The reaction is catalyzed by a combination of (bpy)NiCl2 and a chiral titanocene under reducing conditions. Yields range from 57 to 99% with 78-95% enantiomeric excess. The 30 examples include a variety of functional groups (ether, ester, ketone, nitrile, ketal, trifluoromethyl, sulfonamide, sulfonate ester), both aryl and vinyl halides, and five- to seven-membered rings. The intermediacy of a carbon radical is strongly suggested by the conversion of cyclooctene monoxide to an aryl [3.3.0]bicyclooctanol. PMID:25716775

  19. Examination of mercaptobenzyl sulfonates as catalysts for native chemical ligation: application to the assembly of a glycosylated Glucagon-Like Peptide 1 (GLP-1) analogue.

    PubMed

    Cowper, Ben; Sze, Tsz Mei; Premdjee, Bhavesh; Bongat White, Aileen F; Hacking, Andrew; Macmillan, Derek

    2015-02-21

    3/4-Mercaptobenzyl sulfonates were investigated as aryl thiol catalysts for native chemical ligation (NCL). Whilst catalysing NCL processes at a similar rate to 4-mercaptophenyl acetic acid (MPAA), the increased polarity and solubility of 3-mercaptobenzyl sulfonate in particular may favour its selection as NCL catalyst in many instances. PMID:25605668

  20. Palladium-Catalyzed ipso-Borylation of Aryl Sulfides with Diborons.

    PubMed

    Bhanuchandra, M; Baralle, Alexandre; Otsuka, Shinya; Nogi, Keisuke; Yorimitsu, Hideki; Osuka, Atsuhiro

    2016-06-17

    A catalytic Miyaura-type ipso-borylation of aryl sulfides with diboron reagents has been achieved, providing arylboronate esters of synthetic use. The key conditions to transform inherently reluctant C-S bonds into C-B bonds include a palladium-NHC (N-heterocyclic carbene) precatalyst, bis(pinacolato)diboron, and lithium hexamethyldisilazide. This protocol is applicable to a reasonable range of aryl alkyl sulfides. Twofold borylation was observed in the reaction of diphenyl sulfide. PMID:27267542

  1. Catalytic Asymmetric Ring-Opening Reactions of Aziridines with 3-Aryl-Oxindoles.

    PubMed

    Wang, Linqing; Li, Dan; Yang, Dongxu; Wang, Kezhou; Wang, Jie; Wang, Pengxin; Su, Wu; Wang, Rui

    2016-03-01

    A highly enantioselective ring-opening alkylation reaction between 3-aryl-oxindole and N-(2-picolinoyl) aziridine has been realized for the first time. The reaction is efficiently mediated by a simple in-situ-generated magnesium catalyst and 3,3'-fluorinated-BINOL (BINOL=1,1'-binaphthalene-2,2'-diol) has been identified as a powerful chiral ligand. Notably, the fluorine atom on the chiral ligand plays a key role in providing the desired chiral 3-alkyl-3-aryl oxindoles with excellent enantioselectivities. PMID:26763482

  2. A Structure-Activity Study with Aryl Acylamidases

    PubMed Central

    Villarreal, David T.; Turco, Ronald F.; Konopka, Allan

    1994-01-01

    We examined the relationship between chemical structure and biodegradability of acylanilide herbicides by using a set of model compounds. Four bacterial isolates (one gram-negative and three gram-positive) that grew on acetanilide were used. These soil isolates cleaved the amide bond of acetanilide via an aryl acylamidase reaction, producing aniline and the organic acid acetate. A series of acetanilide analogs with alkyl substitutions on the nitrogen atom or the aromatic ring were tested for their ability to induce aryl acylamidase activity and act as substrates for the enzyme. The substrate range, in general, was limited to those analogs not disubstituted in the ortho position of the benzene ring or which did not contain an alkyl group on the nitrogen atom. These same N-substituted compounds did not induce enzyme activity either, whereas the ortho-substituted compounds could in some cases. PMID:16349428

  3. A structure-activity study with aryl acylamidases.

    PubMed

    Villarreal, D T; Turco, R F; Konopka, A

    1994-11-01

    We examined the relationship between chemical structure and biodegradability of acylanilide herbicides by using a set of model compounds. Four bacterial isolates (one gram-negative and three gram-positive) that grew on acetanilide were used. These soil isolates cleaved the amide bond of acetanilide via an aryl acylamidase reaction, producing aniline and the organic acid acetate. A series of acetanilide analogs with alkyl substitutions on the nitrogen atom or the aromatic ring were tested for their ability to induce aryl acylamidase activity and act as substrates for the enzyme. The substrate range, in general, was limited to those analogs not disubstituted in the ortho position of the benzene ring or which did not contain an alkyl group on the nitrogen atom. These same N-substituted compounds did not induce enzyme activity either, whereas the ortho-substituted compounds could in some cases. PMID:16349428

  4. Cracking of long-chain alkyl aromatics on USY zeolite catalysts

    SciTech Connect

    Corma, A. ); Miguel, P.J.; Orchilles, A.V. ); Koermer, G.S. )

    1992-05-01

    Long-chain alkyl aromatics are important precursors for FCC gasoline. It is well known that for short-chain alkyl aromatics like cumene the dominant cracking process is simple alkyl aryl cleavage. In contrast the authors have found that for long-chain alkyl aromatics like 1-phenylheptane, cracking over in situ USY catalysts is much more complex. Cracking in a long alkyl side chain results in a carbenium ion that isomerizes easily and gives self-alkylation of the aromatic ring. Self-alkylation produces coke precursors and heavy gasoline aromatics. Product selectivities vary with zeolite unit cell size in ways that are rationalized on the basis of decreasing acid site density and zeolite adsorption properties.

  5. Escherichia coli gene that controls sensitivity to alkylating agents.

    PubMed Central

    Yamamoto, Y; Katsuki, M; Sekiguchi, M; Otsuji, N

    1978-01-01

    A new type of Escherichia coli mutant which shows increased sensitivity to methyl methane sulfonate but not to UV light or to gamma rays was isolated after mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine. The mutant is unable to reactivate phage lambdavir or double-stranded phiX174 DNA (replicative form) that had been treated with methyl methane sulfonate. The mutant is sensitive to other alkylating agents, such as ethyl methane sulfonate, mitomycin C, and N-methyl-N'-nitro-N-nitrosoguanidine, as well. It grows normally and exhibits almost normal recombination proficiency. The mutant possesses normal levels of DNA polymerase I, exonuclease I, exonuclease V, endonuclease specific for methyl methane sulfonate-treated DNA, and 3-methyladenine-DNA glycosidase activities. The genetic locus responsible has been named alk and is located near his on the chromosome. PMID:353028

  6. Sulfonated polyphenylene polymers

    DOEpatents

    Cornelius, Christopher J.; Fujimoto, Cy H.; Hickner, Michael A.

    2007-11-27

    Improved sulfonated polyphenylene compositions, improved polymer electrolyte membranes and nanocomposites formed there from for use in fuel cells are described herein. The improved compositions, membranes and nanocomposites formed there from overcome limitations of Nafion.RTM. membranes.

  7. Sodium Polystyrene Sulfonate

    MedlinePlus

    ... comes as a suspension and as an oral powder for suspension to take by mouth. The suspension ... evenly.If you are taking sodium polystyrene sulfonate powder by mouth, mix the powder with 20 to ...

  8. Catalytic alkylation apparatus

    SciTech Connect

    Hann, P.D.; VanPool, J.

    1989-09-05

    This patent describes an apparatus. It comprises alkylation reactor means for producing alkylate product; acid catalyst settler means having an upper portion, an intermediate portion and a lower portion; means for withdrawing alkylate product from the alkylation reactor means and for providing alkylate product from the alkylation reactor means to a point of introduction in the intermediate portion of the acid catalyst settler means; and means for establishing a temperature gradient in the upper the gas lines to the detector so that a flow rate of a sample gas passing through the detector is constant.

  9. Transition-Metal-Free Regioselective Alkylation of Pyridine N-Oxides Using 1,1-Diborylalkanes as Alkylating Reagents.

    PubMed

    Jo, Woohyun; Kim, Junghoon; Choi, Seoyoung; Cho, Seung Hwan

    2016-08-01

    Reported herein is an unprecedented base-promoted deborylative alkylation of pyridine N-oxides using 1,1-diborylalkanes as alkyl sources. The reaction proceeds efficiently for a wide range of pyridine N-oxides and 1,1-diborylalkanes with excellent regioselectivity. The utility of the developed method is demonstrated by the sequential C-H arylation and methylation of pyridine N-oxides. The reaction also can be applied for the direct introduction of a methyl group to 9-O-methylquinine N-oxide, thus it can serve as a powerful method for late-stage functionalization. PMID:27351367

  10. Branch-Selective Alkene Hydroarylation by Cooperative Destabilization: Iridium-Catalyzed ortho-Alkylation of Acetanilides

    PubMed Central

    Crisenza, Giacomo E M; Sokolova, Olga O; Bower, John F

    2015-01-01

    An iridium(I) catalyst system, modified with the wide-bite-angle and electron-deficient bisphosphine dFppb (1,4-bis(di(pentafluorophenyl)phosphino)butane) promotes highly branch-selective hydroarylation reactions between diverse acetanilides and aryl- or alkyl-substituted alkenes. This provides direct and ortho-selective access to synthetically challenging anilines, and addresses long-standing issues associated with related Friedel–Crafts alkylations. PMID:26490739

  11. Palladium-Catalyzed Room-Temperature Acylative Suzuki Coupling of High-Order Aryl Borons with Carboxylic Acids.

    PubMed

    Si, Shufen; Wang, Chen; Zhang, Nan; Zou, Gang

    2016-05-20

    This note describes a dimethyl dicarbonate-assisted, Pd(OAc)2/PPh3-catalyzed acylative Suzuki coupling of carboxylic acids with diarylborinic acids or tetraarylboronates for practical and efficient synthesis of sterically undemanding aryl ketones at room temperature. More than just cost-effective alternatives to aryl boronic acids, diarylborinic acids and tetraarylboronates displayed higher reactivity in the acylative Suzuki coupling. A variety of alkyl aryl ketones, including those bearing a hydroxy, bromo, or carbonyl group, could be readily obtained in modest to excellent yields. PMID:27100118

  12. Palladium-Catalyzed α-Arylation of Aryl Acetic Acid Derivatives via Dienolate Intermediates with Aryl Chlorides and Bromides

    PubMed Central

    2016-01-01

    To date, examples of α-arylation of carboxylic acids remain scarce. Using a deprotonative cross-coupling process (DCCP), a method for palladium-catalyzed γ-arylation of aryl acetic acids with aryl halides has been developed. This protocol is applicable to a wide range of aryl bromides and chlorides. A procedure for the palladium-catalyzed α-arylation of styryl acetic acids is also described. PMID:25582024

  13. Selective, nickel-catalyzed hydrogenolysis of aryl ethers.

    PubMed

    Sergeev, Alexey G; Hartwig, John F

    2011-04-22

    Selective hydrogenolysis of the aromatic carbon-oxygen (C-O) bonds in aryl ethers is an unsolved synthetic problem important for the generation of fuels and chemical feedstocks from biomass and for the liquefaction of coal. Currently, the hydrogenolysis of aromatic C-O bonds requires heterogeneous catalysts that operate at high temperature and pressure and lead to a mixture of products from competing hydrogenolysis of aliphatic C-O bonds and hydrogenation of the arene. Here, we report hydrogenolyses of aromatic C-O bonds in alkyl aryl and diaryl ethers that form exclusively arenes and alcohols. This process is catalyzed by a soluble nickel carbene complex under just 1 bar of hydrogen at temperatures of 80 to 120°C; the relative reactivity of ether substrates scale as Ar-OAr>Ar-OMe>ArCH(2)-OMe (Ar, Aryl; Me, Methyl). Hydrogenolysis of lignin model compounds highlights the potential of this approach for the conversion of refractory aryl ether biopolymers to hydrocarbons. PMID:21512027

  14. 5-Alkyl-2-urea-Substituted Pyridines: Identification of Efficacious Glucokinase Activators with Improved Properties.

    PubMed

    Kohn, Todd J; Du, Xiaohui; Lai, SuJen; Xiong, YuMei; Komorowski, Renee; Veniant, Murielle; Fu, Zice; Jiao, Xianyun; Pattaropong, Vatee; Chow, David; Cardozo, Mario; Jin, Lixia; Conn, Marion; DeWolf, Walter E; Kraser, Christopher F; Hinklin, Ronald J; Boys, Mark L; Medina, Julio C; Houze, Jonathan; Dransfield, Paul; Coward, Peter

    2016-07-14

    Two 1-(4-aryl-5-alkyl-pyridin-2-yl)-3-methylurea glucokinase activators were identified with robust in vivo efficacy. These two compounds possessed higher solubilities than the previously identified triaryl compounds (i.e., AM-2394). Structure-activity relationship studies are presented along with relevant pharmacokinetic and in vivo data. PMID:27437074

  15. Iron-catalyzed arylation of α-aryl-α-diazoesters.

    PubMed

    Yang, Ji-Min; Cai, Yan; Zhu, Shou-Fei; Zhou, Qi-Lin

    2016-06-28

    An iron-catalyzed arylation of α-aryl-α-diazoesters with electron-rich benzene rings was developed, which provides an efficient method for the preparation of 1,1-diarylacetates with high yields and excellent chemo- and regio-selectivities. PMID:26805776

  16. Synthesis of the Privileged 8-Arylmenthol Class by Radical Arylation of Isopulegol.

    PubMed

    Crossley, Steven W M; Martinez, Ruben M; Guevara-Zuluaga, Sebastián; Shenvi, Ryan A

    2016-06-01

    Hydrogen atom transfer (HAT) circumvents a disfavored Friedel-Crafts reaction in the derivatization of the inexpensive monoterpene isopulegol. A variety of readily prepared aryl and heteroaryl sulfonates undergo a formal hydroarylation to form 8-arylmenthols, privileged scaffolds for asymmetric synthesis, as typified by 8-phenylmenthol. High stereoselectivity is observed in related systems. This use of HAT significantly extends the chiral pool from the inexpensive monoterpene isopulegol. PMID:27175746

  17. A reagent for the one-step preparation of potassium acyltrifluoroborates (KATs) from aryl- and heteroarylhalides.

    PubMed

    Erős, Gábor; Kushida, Yo; Bode, Jeffrey W

    2014-07-14

    Potassium acyltrifluoroborates (KATs) are fascinating functional groups whose further exploration is limited by poor synthetic access. Documented herein is the design and synthesis of a new reagent for their one-step preparation from aryl- and heteroarylhalides. The reagent is a stable, soluble zwitterion prepared by S-alkylation of a novel thioformamide trifluoroboronate. The KATs are prepared by adding one equivalent of nBuLi to a mixture of the aryl halide and the reagent at -78 °C. This protocol is suitable for the preparation of KATs containing pyridines, esters, nitro groups, and halides. PMID:24888578

  18. Modular isoquinoline synthesis using catalytic enolate arylation and in situ functionalization.

    PubMed

    Pilgrim, Ben S; Gatland, Alice E; McTernan, Charlie T; Procopiou, Panayiotis A; Donohoe, Timothy J

    2013-12-20

    A methyl ketone, an aryl bromide, an electrophile, and ammonium chloride were combined in a four-component, three-step, and one-pot coupling procedure to furnish substituted isoquinolines in overall yields of up to 80%. This protocol utilizes the palladium catalyzed α-arylation reaction of an enolate, followed by in situ trapping with an electrophile, and aromatization with ammonium chloride. tert-Butyl cyanoacetate participated in a similar protocol; after functionalization and decarboxylation, 3-amino-4-alkyl isoquinolines were prepared in high yield. PMID:24251885

  19. Sulfonated poly(ether sulfone)s containing pyridine moiety for PEMFC.

    PubMed

    Jang, Hohyoun; Islam, Md Monirul; Lim, Youngdon; Hossain, Md Awlad; Cho, Younggil; Joo, Hyunho; Kim, Whangi; Jeon, Heung-Seok

    2014-10-01

    Sulfonated poly(ether sulfone)s with varied degree of sulfonation (DS) were prepared via post-sulfonation of synthesized pyridine based poly(ether sulfone) (PPES) using concentrated sulfuric acid as sulfonating agent. The DS was varied with different mole ratio of 4,4'-(2,2-diphenylethenylidene)diphenol, DHTPE in the polymer unit. PPES copolymers were synthesized by direct polycondensation of pyridine unit with bis-(4-fluorophenyl)-sulfone, 4, 4'-sulfonyldiphenol and DHTPE. The structure of the resulting PPES copolymer membranes with different sulfonated units were studied by 1H NMR spectroscopy and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity were evaluated according to the increase of DS. The water uptake (WU) of the resulting membranes was in the range of 17-58%, compared to that of Nafion 211 28%. The membranes provided proton conductivities of 65-95 mS/cm in contrast to 103 mS/cm of Nafion 211. PMID:25942869

  20. Preparation and synthetic applications of aryl tetraflates (ArOSO2CF2CF2H).

    PubMed

    Rostovtsev, Vsevolod V; Bryman, Lois M; Junk, Christopher P; Harmer, Mark A; Carcani, Liane G

    2008-01-18

    We have recently developed an improved synthetic route to 1,1,2,2-tetrafluoroethanesulfonic acid (HCF2CF2SO3H, TFESA) and explored the applications of this newly available superacid in catalysis. Low volatility, ease of handling, and a convenient 1H NMR handle make this acid an attractive alternative to triflic acid. TFESA can also be converted to several of its derivatives: anhydride, sulfonyl chloride, and sulfonyl fluoride, which provide a good entry point for the synthesis of aryl sulfonates. We prepared several aryl esters of 1,1,2,2-tetrafluoroethanesulfonic acid (aryl tetraflates) and showed that they can be used in a number of palladium-catalyzed coupling reactions (Suzuki, Heck, and Buchwald-Hartwig couplings). While the reactivity of tetraflates lies between that of triflates and chlorides, tetraflates appear to be more thermally stable. Additionally, the presence of a hydrogen atom in the tetraflate group facilitates monitoring of reactions and characterization of derivatives. PMID:18085791

  1. AN EFFICIENT AND SIMPLE AQUEOUS N-HETEROCYCLIZATION OF ANILINE DERIVATIVES: MICROWAVE-ASSISTED SYNTHESIS OF N-ARYL AZACYCLOALKANES

    EPA Science Inventory

    An efficient and clean synthesis of N-aryl azacycloalkanes from alkyl dihalides and aniline derivatives has been achieved using microwave irradiation in an aqueous potassium carbonate medium. The phase separation can simplify the product isolation and reduce usage of vol...

  2. AN EFFICIENT AQUEOUS N-HETEROCYCLIZATION OF ANILINE DERIVATIVES: MICROWAVE-ASSISTED SYNTHESIS OF N-ARYL AZACYCLOALKANES

    EPA Science Inventory

    N-aryl azacycloalkanes, an important class of building blocks in natural product and pharmaceuticals, are synthesized via an efficient and simple eco-friendly protocol that involves double N-alkylation of aniline derivatives. The reaction is accelerated by exposure to microwaves ...

  3. Cross-Couplings Using Aryl Ethers via C-O Bond Activation Enabled by Nickel Catalysts.

    PubMed

    Tobisu, Mamoru; Chatani, Naoto

    2015-06-16

    Arene synthesis has been revolutionized by the invention of catalytic cross-coupling reactions, wherein aryl halides can be coupled with organometallic and organic nucleophiles. Although the replacement of aryl halides with phenol derivatives would lead to more economical and ecological methods, success has been primarily limited to activated phenol derivatives such as triflates. Aryl ethers arguably represent one of the most ideal substrates in terms of availability, cost, safety, and atom efficiency. However, the robust nature of the C(aryl)-O bonds of aryl ethers renders it extremely difficult to use them in catalytic reactions among the phenol derivatives. In 1979, Wenkert reported a seminal work on the nickel-catalyzed cross-coupling of aryl ethers with Grignard reagents. However, it was not until 2004 that the unique ability of a low-valent nickel species to activate otherwise unreactive C(aryl)-O bonds was appreciated with Dankwardt's identification of the Ni(0)/PCy3 system, which significantly expanded the efficiency of the Wenkert reaction. Application of the nickel catalyst to cross-couplings with other nucleophiles was first accomplished in 2008 by our group using organoboron reagents. Later on, several other nucleophiles, including organozinc reagents, amines, hydrosilane, and hydrogen were shown to be coupled with aryl ethers under nickel catalysis. Despite these advances, progress in this field is relatively slow because of the low reactivity of benzene derivatives (e.g., anisole) compared with polyaromatic substrates (e.g., methoxynaphthalene), particularly when less reactive and synthetically useful nucleophiles are used. The "naphthalene problem" has been overcome by the use of N-heterocyclic carbene (NHC) ligands bearing bulky N-alkyl substituents, which enables a wide range of aryl ethers to be coupled with organoboron nucleophiles. Moreover, the use of N-alkyl-substituted NHC ligands allows the use of alkynylmagnesium reagents, thereby realizing

  4. Cobalt co-catalysis for cross-electrophile coupling: diarylmethanes from benzyl mesylates and aryl halides†

    PubMed Central

    2014-01-01

    The nickel-catalyzed cross-coupling of aryl halides with alkyl radicals derived from alkyl halides has recently been extended to couplings with carbon radicals generated by a co-catalyst. In this study, a new co-catalyst, cobalt phthalocyanine (Co(Pc)), is introduced and demonstrated to be effective for coupling substrates not prone to homolysis. This is because Co(Pc) reacts with electrophiles by an SN2 mechanism instead of by the electron-transfer or halogen abstraction mechanisms previously explored. Studies demonstrating the orthogonal reactivity of (bpy)Ni and Co(Pc), applying this selectivity to the coupling of benzyl mesylates with aryl halides, and the adaptation of these conditions to the less reactive benzyl phosphate ester and an enantioconvergent reaction are presented. PMID:25685312

  5. Cross-Electrophile Coupling of Vinyl Halides with Alkyl Halides.

    PubMed

    Johnson, Keywan A; Biswas, Soumik; Weix, Daniel J

    2016-05-23

    An improved method for the reductive coupling of aryl and vinyl bromides with alkyl halides that gave high yields for a variety of substrates at room temperature with a low (2.5 to 0.5 mol %) catalyst loading is presented. Under the optimized conditions, difficult substrates, such as unhindered alkenyl bromides, can be coupled to give the desired olefins with minimal diene formation and good stereoretention. These improved conditions also worked well for aryl bromides. For example, a gram-scale reaction was demonstrated with 0.5 mol % catalyst loading, whereas reactions at 10 mol % catalyst loading completed in as little as 20 minutes. Finally, a low-cost single-component pre-catalyst, (bpy)NiI2 (bpy=2,2'-bipyridine) that is both air- and moisture-stable over a period of months was introduced. PMID:27017436

  6. Aryl substitution of pentacenes

    PubMed Central

    Waterloo, Andreas R; Sale, Anna-Chiara; Lehnherr, Dan; Hampel, Frank

    2014-01-01

    Summary A series of 11 new pentacene derivatives has been synthesized, with unsymmetrical substitution based on a trialkylsilylethynyl group at the 6-position and various aryl groups appended to the 13-position. The electronic and physical properties of the new pentacene chromophores have been analyzed by UV–vis spectroscopy (solution and thin films), thermoanalytical methods (DSC and TGA), cyclic voltammetry, as well as X-ray crystallography (for 8 derivatives). X-ray crystallography has been specifically used to study the influence of unsymmetrical substitution on the solid-state packing of the pentacene derivatives. The obtained results add to our ability to better predict substitution patterns that might be helpful for designing new semiconductors for use in solid-state devices. PMID:25161729

  7. Highly Enantioselective Rhodium-Catalyzed Addition of Arylboroxines to Simple Aryl Ketones: Efficient Synthesis of Escitalopram.

    PubMed

    Huang, Linwei; Zhu, Jinbin; Jiao, Guangjun; Wang, Zheng; Yu, Xingxin; Deng, Wei-Ping; Tang, Wenjun

    2016-03-24

    Highly enantioselective additions of arylboroxines to simple aryl ketones have been achieved for the first time with a Rh/(R,R,R,R)-WingPhos catalyst, thus providing a range of chiral diaryl alkyl carbinols with excellent ee values and yields. (R,R,R,R)-WingPhos has been proven to be crucial for the high reactivity and enantioselectivity. The method has enabled a new, concise, and enantioselective synthesis of the antidepressant drug escitalopram. PMID:26933831

  8. Tandem Esterification/1,4-Addition-Type Friedel-Crafts Alkylation Reactions of Phenols/Naphthols with Olefinic Thioazlactones: Access to Functionalized 1,2-Dihydrobenzo[f]chromen-3-ones and 3,4-Dihydrochromen-2-ones.

    PubMed

    Ziyaei Halimehjani, Azim; Khoshdoun, Maryam

    2016-07-01

    An efficient approach for the synthesis of novel alkyl 2,3-dihydro-3-oxo-1-aryl-1H-benzo[f]chromen-2-ylcarbamodithioates and alkyl 3,4-dihydro-2-oxo-4-aryl-2H-chromen-3-ylcarbamodithioates from 2-(alkylthio)thioazlactones (thioazlactones) and phenols or naphthols catalyzed by PTSA was developed. The reaction proceeds via a domino esterification/intramolecular 1,4-addition-type Friedel-Crafts alkylation reaction to afford interesting complex molecules by a simple procedure with high yields and diastereoselectivity. An X-ray analysis was carried out to firmly establish the stereochemistry of the products. PMID:27310869

  9. Selective and Serial Suzuki-Miyaura Reactions of Polychlorinated Aromatics with Alkyl Pinacol Boronic Esters.

    PubMed

    Laulhé, Sébastien; Blackburn, J Miles; Roizen, Jennifer L

    2016-09-01

    Among cross-coupling reactions, the Suzuki-Miyaura transformation stands out because of its practical advantages, including the commercial availability and low toxicity of the required reagents, mild reaction conditions, and functional group compatibility. Nevertheless, few conditions can be used to cross-couple alkyl boronic acids or esters with aryl halides, especially 2-pyridyl halides. Herein, we describe two novel Suzuki-Miyaura protocols that enable selective conversion of polychlorinated aromatics, with a focus on reactions to convert 2,6-dichloropyridines to 2-chloro-6-alkylpyridines or 2-aryl-6-alkylpyridines. PMID:27537216

  10. Stereochemical influences upon the opioid ligand activities of 4-alkyl-4-arylpiperidine derivatives.

    PubMed

    Casy, A F; Dewar, G H; al Deeb, O A

    1989-01-01

    The synthesis and stereochemistry (configuration and preferred solute conformation) of some 4-alkyl (methyl, n-propyl, isobutyl)-4-(3-hydroxy-phenyl)-1-methylpiperidines and corresponding 3-methyl diastereoisomeric pairs are reported, together with their in vivo and in vitro activities as opioid ligands. All potent agonists exhibit a preference for axial 4-aryl chair conformations when protonated, and stereochemical analogies with rigid opioids of the benzomorphan class are discussed. Antagonist properties are found in compounds with preference for equatorial 4-aryl chairs, notably the cis 3,4-dimethyl derivative. PMID:2561991

  11. Oligo(N-aryl glycines): a new twist on structured peptoids.

    PubMed

    Shah, Neel H; Butterfoss, Glenn L; Nguyen, Khanh; Yoo, Barney; Bonneau, Richard; Rabenstein, Dallas L; Kirshenbaum, Kent

    2008-12-10

    We explore strategies to enhance conformational ordering of N-substituted glycine peptoid oligomers. Peptoids bearing bulky N-alkyl side chains have previously been studied as important examples of biomimetic "foldamer" compounds, as they exhibit a capacity to populate helical structures featuring repeating cis-amide bonds. Substantial cis/trans amide bond isomerization, however, gives rise to conformational heterogeneity. Here, we report the use of N-aryl side chains as a tool to enforce the presence of trans-amide bonds, thereby engendering structural stability. Aniline derivatives and bromoacetic acid are used in the facile solid-phase synthesis of a diverse family of sequence-specific N-aryl glycine oligomers. Quantum mechanics calculations yield a detailed energy profile of the folding landscape and substantiate the hypothesis that the presence of anilide groups establishes a strong energetic preference for trans-amide bonds. X-ray crystallographic analysis and solution NMR studies verify this preference. Molecular modeling indicates that the linear oligomers can adopt helical structures resembling a polyproline type II helix. High resolution structures of macrocyclic oligomers incorporating both N-alkyl and N-aryl glycine units confirm the ability to direct the presence of trans-amide bonds specifically at N-aryl positions. These results are an important step in developing strategies for the rational de novo design of new structural motifs in biomimetic oligopeptoid systems. PMID:19049458

  12. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  13. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  14. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  15. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  16. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  17. Rh(I)-Catalyzed Direct Arylation of Pyridines and Quinolines

    SciTech Connect

    Berman, Ashley; Lewis, Jared; Bergman, Robert; Ellman, Jonathan

    2008-07-29

    The pyridine and quinoline nuclei are privileged scaffolds that occupy a central role in many medicinally relevant compounds. Consequently, methods for their expeditious functionalization are of immediate interest. However, despite the immense importance of transition-metal catalyzed cross-coupling for the functionalization of aromatic scaffolds, general solutions for coupling 2-pyridyl organometallics with aryl halides have only recently been presented. Direct arylation at the ortho position of pyridine would constitute an even more efficient approach because it eliminates the need for the stoichiometric preparation and isolation of 2-pyridyl organometallics. Progress towards this goal has been achieved by activation of the pyridine nucleus for arylation via conversion to the corresponding pyridine N-oxide or N-iminopyridinium ylide. However, this approach necessitates two additional steps: activation of the pyridine or quinoline starting material, and then unmasking the arylated product. The use of pyridines directly would clearly represent the ideal situation both in terms of cost and simplicity. We now wish to document our efforts in this vein, culminating in an operationally simple Rh(I)-catalyzed direct arylation of pyridines and quinolines. We recently developed an electron-rich Rh(I) system for catalytic alkylation at the ortho position of pyridines and quinolines with alkenes. Therefore, we initially focused our attention on the use of similarly electron-rich Rh(I) catalysts for the proposed direct arylation. After screening an array of electron-rich phosphine ligands and Rh(I) salts, only marginal yields (<20%) of the desired product were obtained. Much more efficient was an electron-poor Rh(I) system with [RhCl(CO){sub 2}]{sub 2} as precatalyst (Table 1). For the direct arylation of picoline with 3,5-dimethyl-bromobenzene, addition of P(OiPr){sub 3} afforded a promising 40% yield of the cross coupled product 1a (entry 1). The exclusion of phosphite

  18. Alkylating potential of oxetanes.

    PubMed

    Gómez-Bombarelli, Rafael; Palma, Bernardo Brito; Martins, Célia; Kranendonk, Michel; Rodrigues, Antonio S; Calle, Emilio; Rueff, José; Casado, Julio

    2010-07-19

    Small, highly strained heterocycles are archetypical alkylating agents (oxiranes, beta-lactones, aziridinium, and thiirinium ions). Oxetanes, which are tetragonal ethers, are higher homologues of oxiranes and reduced counterparts of beta-lactones, and would therefore be expected to be active alkylating agents. Oxetanes are widely used in the manufacture of polymers, especially in organic light-emitting diodes (OLEDs), and are present, as a substructure, in compounds such as the widely used antimitotic taxol. Whereas the results of animal tests suggest that trimethylene oxide (TMO), the parent compound, and beta,beta-dimethyloxetane (DMOX) are active carcinogens at the site of injection, no studies have explored the alkylating ability and genotoxicity of oxetanes. This work addresses the issue using a mixed methodology: a kinetic study of the alkylation reaction of 4-(p-nitrobenzyl)pyridine (NBP), a trap for alkylating agents with nucleophilicity similar to that of DNA bases, by three oxetanes (TMO, DMOX, and methyloxetanemethanol), and a mutagenicity, genotoxicity, and cell viability study (Salmonella microsome test, BTC E. coli test, alkaline comet assay, and MTT assay). The results suggest either that oxetanes lack genotoxic capacity or that their mode of action is very different from that of epoxides and beta-lactones. PMID:20550097

  19. Practical Ni-Catalyzed Aryl–Alkyl Cross-Coupling of Secondary Redox-Active Esters

    PubMed Central

    2016-01-01

    A new transformation is presented that enables chemists to couple simple alkyl carboxylic acids with aryl zinc reagents under Ni-catalysis. The success of this reaction hinges on the unique use of redox-active esters that allow one to employ such derivatives as alkyl halides surrogates. The chemistry exhibits broad substrate scope and features a high degree of practicality. The simple procedure and extremely inexpensive nature of both the substrates and pre-catalyst (NiCl2·6H2O, ca. $9.5/mol) bode well for the immediate widespread adoption of this method. PMID:26835704

  20. High lipophilicity of perfluoroalkyl carboxylate and sulfonate: implications for their membrane permeability.

    PubMed

    Jing, Ping; Rodgers, Patrick J; Amemiya, Shigeru

    2009-02-18

    Here we report on remarkably high lipophilicity of perfluoroalkyl carboxylate and sulfonate. A lipophilic nature of this emerging class of organic pollutants has been hypothesized as an origin of their bioaccumulation and toxicity. Both carboxylate and sulfonate, however, are considered hydrophilic while perfluroalkyl groups are not only hydrophobic but also oleophobic. Partition coefficients of a homologous series of perfluoroalkyl and alkyl carboxylates between water and n-octanol were determined as a measure of their lipophilicity by ion-transfer cyclic voltammetry. Very similar lipophilicity of perfluoroalkyl and alkyl chains with the same length is demonstrated experimentally for the first time by fragment analysis of the partition coefficients. This finding is important for pharmaceutical and biomedical applications of perfluoroalkyl compounds. Interestingly, approximately 2 orders of magnitude higher lipophilicity of a perfluoroalkyl carboxylate or sulfonate in comparison to its alkyl counterpart is ascribed nearly exclusively to their oxoanion groups. The higher lipophilicity originates from a strong electron-withdrawing effect of the perfluoroalkyl group on the adjacent oxoanion group, which is weakly hydrated to decrease its hydrophilicity. In fact, the inductive effect is dramatically reduced for a fluorotelomer with an ethylene spacer between perfluorohexyl and carboxylate groups, which is only as lipophilic as its alkyl counterpart, nonanoate, and is 400 times less lipophilic than perfluorononanoate. The high lipophilicity of perfluoroalkyl carboxylate and sulfonate implies that their permeation across such a thin lipophilic membrane as a bilayer lipid membrane is limited by their transfer at a membrane/water interface. The limiting permeability is lower and less dependent on their lipophilicity than the permeability controlled by their diffusion in the membrane interior as assumed in the classical solubility-diffusion model. PMID:19170492

  1. Determining cysteine oxidation status using differential alkylation

    NASA Astrophysics Data System (ADS)

    Schilling, Birgit; Yoo, Chris B.; Collins, Christopher J.; Gibson, Bradford W.

    2004-08-01

    Oxidative damage to proteins plays a major role in aging and in the pathology of many degenerative diseases. Under conditions of oxidative stress, reactive oxygen and nitrogen species can modify key redox sensitive amino acid side chains leading to altered biological activities or structures of the targeted proteins. This in turn can affect signaling or regulatory control pathways as well as protein turnover and degradation efficiency in the proteasome. Cysteine residues are particularly susceptible to oxidation, primarily through reversible modifications (e.g., thiolation and nitrosylation), although irreversible oxidation can lead to products that cannot be repaired in vivo such as sulfonic acid. This report describes a strategy to determine the overall level of reversible cysteine oxidation using a stable isotope differential alkylation approach in combination with mass spectrometric analysis. This method employs 13C-labeled alkylating reagents, such as N-ethyl-[1,4-13C2]-maleimide, bromo-[1,2-13C2]-acetic acid and their non-labeled counterparts to quantitatively assess the level of cysteine oxidation at specific sites in oxidized proteins. The differential alkylation protocol was evaluated using standard peptides and proteins, and then applied to monitor and determine the level of oxidative damage induced by diamide, a mild oxidant. The formation and mass spectrometric analysis of irreversible cysteine acid modification will also be discussed as several such modifications have been identified in subunits of the mitochondrial electron transport chain complexes. This strategy will hopefully contribute to our understanding of the role that cysteine oxidation plays in such chronic diseases such as Parkinson's disease, where studies in animal and cell models have shown oxidative damage to mitochondrial Complex I to be a specific and early target.

  2. Sulfonated Polyamide Based IPMCs

    NASA Astrophysics Data System (ADS)

    Park, Il-Seok; Bae, Chulsung; Jo, Tae Soo; Truong, Justina; Kim, Sang-Mun; Kim, Kwang J.; Yim, Woosoon; Lee, Joon-Soo

    2009-03-01

    In this study, we introduce a newly developed Ionic Polymer-Metal Composite (IPMC) family that is manufactured using a novel ionic exchange membrane-a randomly sulfonated fluoropoly(ether amide) (TFIPA-90)-as the base material. The thermal behavior and mechanical properties of the ionic polymer were probed by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Electrochemical properties and the actuation performance of the TFIPA-90 based IPMCs were also investigated in this study. The stiffness of the TFIPA polymer was significantly higher than that of Nafion® and much noted at high temperatures (>100 oC). The thermal behavior of the TFIPA polymer also showed better stability than Nafion(R) at high temperatures due to the more rigid chemical structure of the ionomer. As an actuator, a new IPMC prepared from TFIPA-90 showed improved performance with rapid response time to the electric field and a large bending displacement. The TFIPA-based IPMC may be useful for microwave-driven robotic applications.

  3. Application of 15N nuclear magnetic resonance spectroscopy to the determination of the stability of aryl nitrogen mustards.

    PubMed

    Wilman, D E; Palmer, B D; Denny, W A

    1995-06-01

    An excellent correlation has been shown to exist between the 15N NMR chemical shifts of a series of aryl nitrogen mustards and the Hammett constant, sigma, which is much improved by the use of sigma-. These chemical shifts also correlate well with the hydrolysis rates of the compounds in 50% aqueous acetone at 66 degrees C and their alkylation of 4-(4'-nitrobenzyl)pyridine under similar conditions. Thus 15N NMR is a straightforward and material-conserving method for estimating the relative stabilities of aryl nitrogen mustards. PMID:7783158

  4. Dehydrozingerone based 1-acetyl-5-aryl-4,5-dihydro-1H-pyrazoles: Synthesis, characterization and anticancer activity

    NASA Astrophysics Data System (ADS)

    Ratković, Zoran; Muškinja, Jovana; Burmudžija, Adrijana; Ranković, Branislav; Kosanić, Marijana; Bogdanović, Goran A.; Marković, Bojana Simović; Nikolić, Aleksandar; Arsenijević, Nebojša; Đorđevic, Snežana; Vukićević, Rastko D.

    2016-04-01

    A small series of 1-acetyl-5-aryl-4,5-dihydro-1H-pyrazoles (aryl = 4-hydroxy-3-methoxyphenyl and 4-alkoxy-3-methoxyphenyl) was prepared, starting from 4-(4-hydroxy-3-methoxyphenyl)-3-buten-2-one, dehydrozingerone, and its alkyl derivatives. Their in vitro cytotoxic activity against some cancer cell lines was tested, showing significant anticancer activity. All the new compounds were well characterized by IR, 1H, 13C NMR and ESI-MS spectroscopy and physical data, whereas structures of two of them were determined by single crystal X-ray analysis.

  5. Synthesis and antioxidant activity of O-alkyl selenocarbamates, selenoureas and selenohydantoins.

    PubMed

    Merino-Montiel, Penélope; Maza, Susana; Martos, Sergio; López, Óscar; Maya, Inés; Fernández-Bolaños, José G

    2013-02-14

    The preparation of three different families of lipophilic organoselenium compounds (aryl- and sugar-derived selenoureas, O-alkyl selenocarbamates and selenohydantoins) has been carried out in order to evaluate their in vitro antioxidant profile, analyzing the influence of the selenium-containing functional group, and the substituents on the activity. Title compounds have therefore been studied for the first time as free radical, hydrogen peroxide, alkyl peroxides and nitric oxide scavengers using colorimetric methods; furthermore, their glutathione peroxidase-like activity has also been analyzed by NMR spectroscopy. Free radical scavenging activity has been evaluated using the DPPH method; the strongest free radical scavengers were found to be both, aryl- and sugar-derived selenoureas, with EC₅₀ values ranging 19-46 μM. Concerning anti-H₂O₂ activity, measured by the horseradish peroxidase-mediated oxidation of phenol red, the best results were achieved for aryl selenohydantoins, showing a 61-76% inhibition at 0.5 mM concentration. Organoselenium compounds were also found to be capable of inhibiting the chain reaction involving lipid peroxidation (ferric thiocyanate method); thus, when tested at 0.74 mM, sugar selenocarbamates exhibited 49-71% inhibition of alkyl peroxides-mediated degradation of linoleic acid. Nitric oxide scavenging was studied by transforming sodium nitroprusside into nitrite ion, which in turn was transformed into an easily UV-detectable azocompound; aryl selenocarbamates exhibited 64-80% inhibition at 0.71 mM concentration. It has also been demonstrated that selenoxo compounds can behave as excellent glutathione peroxidase mimics; thus a 0.05 molar equiv. of the title compounds catalyzed efficiently the H₂O₂-mediated oxidation of dithiothreitol into the corresponding cyclic disulfide, mimicking removal of H₂O₂ exerted by glutathione peroxidase; t(1/2) values were found to be quite low for aryl- and sugar-derived selenoureas (2

  6. Aryl bromides as inexpensive starting materials in the catalytic enantioselective arylation of aryl aldehydes: the additive TMEDA enhances the enantioselectivity.

    PubMed

    Yang, Yong-Xin; Liu, Yue; Zhang, Lei; Jia, Yan-E; Wang, Pei; Zhuo, Fang-Fang; An, Xian-Tao; Da, Chao-Shan

    2014-11-01

    We used aryl bromides as inexpensive starting materials to enantioselectively arylate aldehydes in one pot. Aryl bromides readily transfer aryls to aryllithiums with n-butyllithium, successively to triarylaluminums with aluminum chloride, and then to aryltitaniums with titanium isopropoxide. Finally aryltitaniums arylate aldehydes catalyzed by (S)-H8-BINOL-Ti(Oi-Pr)2 in excellent yields and enantioselectivities. The additive TMEDA evidently suppresses the racemic background reaction promoted by LiCl generated from salt metathesis. This procedure represents a cost-effective and operationally convenient method for enantioenriched diarylmethanols. PMID:25279967

  7. Synthesis and Antioxidant Activity of Alkyl Nitroderivatives of Hydroxytyrosol.

    PubMed

    Gallardo, Elena; Palma-Valdés, Rocío; Sarriá, Beatriz; Gallardo, Irene; de la Cruz, José P; Bravo, Laura; Mateos, Raquel; Espartero, José L

    2016-01-01

    A series of alkyl nitrohydroxytyrosyl ether derivatives has been synthesized from free hydroxytyrosol (HT), the natural olive oil phenol, in order to increase the assortment of compounds with potential neuroprotective activity in Parkinson's disease. In this work, the antioxidant activity of these novel compounds has been evaluated using Ferric Reducing Antioxidant Power (FRAP), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), and Oxygen Radical Scavenging Capacity (ORAC) assays compared to that of nitrohydroxytyrosol (NO₂HT) and free HT. New compounds showed variable antioxidant activity depending on the alkyl side chain length; compounds with short chains (2-4 carbon atoms) maintained or even improved the antioxidant activity compared to NO₂HT and/or HT, whereas those with longer side chains (6-8 carbon atoms) showed lower activity than NO₂HT but higher than HT. PMID:27213306

  8. Thermal stability of sulfonated polymers

    SciTech Connect

    Audibert, A.; Argillier, J.F.

    1995-11-01

    Polyacrylamides which are used in oil applications i.e. polymer flooding and water based muds, are hydrolyzed versus time and temperature. This leads to a lack of tolerance towards electrolyte contamination and to a rapid degradation inducing a loss of their properties. Modifications of polyacrylamide structure have been proposed to postpone their thermal stability to higher temperatures. Monomers such as acrylamido methylpropane sulfonate (AMPS) or sulfonated styrene/maleic anhydride can be used to prevent acrylamide comonomer from hydrolysis. The aim of this work is to study under controlled conditions, i.e. anaerobic atmosphere, neutral pH, the stability of sulfonated polymers in order to distinguish between hydrolysis and radical degradation reactions. It has been observed that up to 100 C, the AMPS group is stable and protects the acrylamide function from hydrolysis up to 80%. At higher temperature, even the hydrolysis of the AMPS group occurs, giving acrylate and {beta},{beta} dimethyl taurine, with a kinetics that depends on temperature and time. Degradation in terms of molecular weight then occurs indicating that it follows a radical decarboxylation reaction. It can be limited either by the use of free radical scavenger or when the polymer is in the presence of a mineral phase such as bentonite. These results provide valuable data for the determination of the limits of use of sulfonated copolymers and guidelines for optimizing chemical structure of sulfonated polymers used in water based formulation, in particular to enhance their thermal stability.

  9. Isotopic Measurements of Organic Sulfonates From The Murchison Meteorite

    NASA Technical Reports Server (NTRS)

    Cooper, G. W.; Chang, S.; DeVincenzi, Donald L. (Technical Monitor)

    1995-01-01

    Organic sulfonates and phosphonates have been extracted from the Murchison meteorite for stable isotope measurements. Preliminary stable isotope measurements of individual alkyl sulfonates, R-SO3H (R=C(sub n)H(sub 2n+l)), are shown. These compounds were found in aqueous extracts of Murchison. Both groups show trends similar to other homologous series of organic compounds indigenous to Murchison. Molecular abundances decrease with increasing carbon number, and all possible isomers at each carbon number (through C-4) are present. Carbon isotope measurements of the sulfonates show a decrease in the C-13/C-12 ratio with increasing carbon number. The overall objectives of this project are to obtain dime element carbon, hydrogen, and sulfur - intramolecular isotopic analyses of individual sulfonates, and isotopic measurement of carbon and hydrogen of the phosphonates as a group. The Murchison meteorite is the best characterized carbonaceous chondrite with respect to organic chemistry. The finding of organic sulfonates and phosphonates in Murchison is of interest because they are the first well-characterized series of sulfur and phosphorus containing organic compounds found in meteorites. Also, meteorites, comets, and interplanetary dust particles may have been involved in chemical evolution on the early Earth. Because of the critical role of organic phosphorus and sulfur in all living systems, it is particularly interesting to see examples of abiotic syntheses of these classes of compounds. The study of the isotopic composition of the sulfonates and phosphonates can yield insight into their possible interstellar origin as well as their mechanisms of synthesis in the early solar system. Previous isotopic analyses of other classes of organic compounds indigenous to meteorites, e.g., amino acids, carboxylic acids, and hydrocarbons indicate the possibility that interstellar molecules were incorporated into meteorite parent bodies. In these compounds the ratios of heavy to

  10. Molecular engineering of porous silica using aryl templates

    DOEpatents

    Loy, Douglas A.; Shea, Kenneth J.

    1994-01-01

    A process for manipulating the porosity of silica using a series of organic template groups covalently incorporated into the silicate matrix. The templates in the bridged polysilsesquioxanes are selectively removed from the material by oxidation with oxygen plasma or other means, leaving engineered voids or pores. The size of these pores is dependent upon the length or size of the template or spacer. The size of the templates is measured in terms of Si-Si distances which range from about 0.67 nm to 1.08 nm. Changes introduced by the loss of the templates result in a narrow range of micropores (i.e. <2 nm). Both aryl and alkyl template groups are used as spacers. Novel microporous silica materials useful as molecular seives, dessicants, and catalyst supports are produced.

  11. Molecular engineering of porous silica using aryl templates

    DOEpatents

    Loy, D.A.; Shea, K.J.

    1994-06-14

    A process is described for manipulating the porosity of silica using a series of organic template groups covalently incorporated into the silicate matrix. The templates in the bridged polysilsesquioxanes are selectively removed from the material by oxidation with oxygen plasma or other means, leaving engineered voids or pores. The size of these pores is dependent upon the length or size of the template or spacer. The size of the templates is measured in terms of Si-Si distances which range from about 0.67 nm to 1.08 nm. Changes introduced by the loss of the templates result in a narrow range of micropores (i.e. <2 nm). Both aryl and alkyl template groups are used as spacers. Novel microporous silica materials useful as molecular sieves, desiccants, and catalyst supports are produced. 3 figs.

  12. Influence of group composition of sulfonic acids on properties of sulfonate additives

    SciTech Connect

    Katrenko, T.I.; Bessonova, R.N.; Kuznetsova, M.G.; Potolovskii, L.A.

    1983-05-01

    Three types of sulfonic acids are formed in sulfonation of petroleum oils-- oil-soluble, oil-insoluble, and water-soluble. This study investigates the influence of the different acids on neutral calcium sulfonates. Samples are recovered from As-14 oil. Oil-insoluble synthesis failed. Water-soluble acid did synthesize with a mix of oil- and water-soluble sulfonates. Neutral calcium sulfonates synthesized from oil-soluble had good properties, from oil-insoluble, bad properties. Oil-insoluble sulfonate also has an inverse effect on cleanup, and it interferes with carbonation. These findings will help with improvements in the sulfonate additive manufacturing process.

  13. Drilling fluids based on a mixture of a sulfonated thermoplastic polymer and a sulfonated elastomeric polymer

    SciTech Connect

    Turner, S.R.; Lundberg, R.D.; Peiffer, D.G.; Thaler, W.A.; Walker, T.O.

    1984-01-10

    The present invention relates to mixtures of sulfonated thermoplastic polymers and sulfonated elastomeric polymers which function as viscosification agents when added to oil-based drilling muds which are the fluids used to maintain pressure, cool drill bits, and lift cuttings from the holes in the drilling operation for oil and gas wells. The sulfonated thermoplastic and elastomeric polymers both have about 5 to about 200 meq. of sulfonate groups per 100 grams of the sulfonated thermoplastic or elastomeric polymers, wherein the sulfonated groups are neutralized with a metallic cation or an amine or ammonium counterion. A polar cosolvent can optionally be added to the mixture of oil drilling mud and sulfonated thermoplastic and elastomeric polymers, wherein the polar cosolvent increases the solubility of the sulfonated thermoplastic and elastomeric polymer in the oil drilling mud by decreasing the strong ionic interactions between the sulfonate groups of the sulfonated polymers.

  14. Hetero-Diels-Alder reactions of hetaryl and aryl thioketones with acetylenic dienophiles.

    PubMed

    Mlostoń, Grzegorz; Grzelak, Paulina; Mikina, Maciej; Linden, Anthony; Heimgartner, Heinz

    2015-01-01

    Selected hetaryl and aryl thioketones react with acetylenecarboxylates under thermal conditions in the presence of LiClO4 or, alternatively, under high-pressure conditions (5 kbar) at room temperature yielding thiopyran derivatives. The hetero-Diels-Alder reaction occurs in a chemo- and regioselective manner. The initially formed [4 + 2] cycloadducts rearrange via a 1,3-hydrogen shift sequence to give the final products. The latter were smoothly oxidized by treatment with mCPBA to the corresponding sulfones. PMID:26124858

  15. Hetero-Diels–Alder reactions of hetaryl and aryl thioketones with acetylenic dienophiles

    PubMed Central

    Grzelak, Paulina; Mikina, Maciej; Linden, Anthony

    2015-01-01

    Summary Selected hetaryl and aryl thioketones react with acetylenecarboxylates under thermal conditions in the presence of LiClO4 or, alternatively, under high-pressure conditions (5 kbar) at room temperature yielding thiopyran derivatives. The hetero-Diels–Alder reaction occurs in a chemo- and regioselective manner. The initially formed [4 + 2] cycloadducts rearrange via a 1,3-hydrogen shift sequence to give the final products. The latter were smoothly oxidized by treatment with mCPBA to the corresponding sulfones. PMID:26124858

  16. Chiral N-1-adamantyl-N-trans-cinnamylaniline type ligands: synthesis and application to palladium-catalyzed asymmetric allylic alkylation of indoles.

    PubMed

    Mino, Takashi; Nishikawa, Kenji; Asano, Moeko; Shima, Yamato; Ebisawa, Toshibumi; Yoshida, Yasushi; Sakamoto, Masami

    2016-08-21

    Such chiral phosphine-internal olefin hybrid type ligands as N-1-adamantyl-N-cinnamylaniline derivatives 1 with C(aryl)-N(amine) bond axial chirality were synthesized and utilized for the palladium-catalyzed asymmetric allylic alkylation of indoles to afford the desired products in high enantioselectivities (up to 98% ee). PMID:27425209

  17. Phycotoxicity of linear alkylbenzene sulfonate

    SciTech Connect

    Chawla, G.; Viswanathan, P.N.; Devi, S.

    1988-04-01

    Dose- and time-dependent effects of linear alkylbenzene sulfonate, a major component of synthetic detergent, to the blue-green alga Nostoc muscorum, were studied under laboratory conditions. Toxicity was evident, at doses above 0.001%, from the decrease in biomass, heterocyst number, and protein content and pathomorphological alterations.

  18. p-Chlorophenyl methyl sulfone

    Integrated Risk Information System (IRIS)

    p - Chlorophenyl methyl sulfone ; CASRN 98 - 57 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for No

  19. Pd-Catalyzed C-H Alkylation of Arenes Using PyrDipSi, a Transformable and Removable Silicon-Tethered Directing Group.

    PubMed

    Sarkar, Dhruba; Gevorgyan, Vladimir

    2016-08-01

    An efficient Pd-catalyzed ortho-C-H alkylation reaction of arenes using a transformable and removable Si-tethered pyridyldiisopropylsilyl (PyrDipSi) directing group has been developed. In addition, the PyrDipSi directing group allows for an efficient sequential double-fold C-H alkylation/oxygenation of arenes to produce meta-alkylated phenols. This directing group can easily be removed or converted into valuable functionalities, such as aryl, iodo, boronic ester, or phenol. PMID:27272930

  20. Method of making alkyl esters

    DOEpatents

    Elliott, Brian

    2010-09-14

    Methods of making alkyl esters are described herein. The methods are capable of using raw, unprocessed, low-cost feedstocks and waste grease. Generally, the method involves converting a glyceride source to a fatty acid composition and esterifying the fatty acid composition to make alkyl esters. In an embodiment, a method of making alkyl esters comprises providing a glyceride source. The method further comprises converting the glyceride source to a fatty acid composition comprising free fatty acids and less than about 1% glyceride by mass. Moreover, the method comprises esterifying the fatty acid composition in the presence of a solid acid catalyst at a temperature ranging firm about 70.degree. C. to about 120.degree. C. to produce alkyl esters, such that at least 85% of the free fatty acids are converted to alkyl esters. The method also incorporates the use of packed bed reactors for glyceride conversion and/or fatty acid esterification to make alkyl esters.

  1. Syntheses and analytical characterizations of N-alkyl-arylcyclohexylamines.

    PubMed

    Wallach, Jason; Colestock, Tristan; Cicali, Brian; Elliott, Simon P; Kavanagh, Pierce V; Adejare, Adeboye; Dempster, Nicola M; Brandt, Simon D

    2016-08-01

    The rise in new psychoactive substances that are available as 'research chemicals' (RCs) remains a significant forensic and legislative challenge. A number of arylcyclohexylamines have attracted attention as RCs and continue to be encountered, including 3-MeO-PCP, 3-MeO-PCE and 3-MeO-PCPr. These compounds are commonly perceived as ketamine-like dissociative substances and are believed to act predominantly via antagonism of the N-methyl-D-aspartate (NMDA) receptor. To aid in the identification of newly emerging substances of abuse, the current studies were performed. The syntheses of fifteen N-alkyl-arylcyclohexylamines are described. Analytical characterizations were performed via gas chromatography and high performance liquid chromatography coupled to multiple forms of mass spectrometry as well as nuclear magnetic resonance spectroscopy, ultraviolet diode array detection and infrared spectroscopy. The series consisted of the N-alkyl derivatives (N-methyl, N-ethyl, N-propyl) of phenyl-substituted and isomeric 2-, 3- and 4-methoxy phenylcyclohexylamines, as well as the N-alkyl derivatives obtained from 3-methylphenyl and 2-thienyl moieties. In addition to the presentation of a range of previously unreported data, it was also found that positional isomers of aryl methoxyl-substituted arylcyclohexylamines were readily distinguishable under a variety of analytical conditions. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26360516

  2. Nucleophilic arylation with tetraarylphosphonium salts

    PubMed Central

    Deng, Zuyong; Lin, Jin-Hong; Xiao, Ji-Chang

    2016-01-01

    Organic phosphonium salts have served as important intermediates in synthetic chemistry. But the use of a substituent on the positive phosphorus as a nucleophile to construct C–C bond remains a significant challenge. Here we report an efficient transition-metal-free protocol for the direct nucleophilic arylation of carbonyls and imines with tetraarylphosphonium salts in the presence of caesium carbonate. The aryl nucleophile generated from phosphonium salt shows low basicity and good nucleophilicity, as evidenced by the successful conversion of enolizable aldehydes and ketones. The reaction is not particularly sensitive to water, shows wide substrate scope, and is compatible with a variety of functional groups including cyano and ester groups. Compared with the arylmetallic reagents that are usually moisture sensitive, the phosphonium salts are shelf-stable and can be easily handled. PMID:26822205

  3. Carbonylation reactions of alkyl iodides through the interplay of carbon radicals and Pd catalysts.

    PubMed

    Sumino, Shuhei; Fusano, Akira; Fukuyama, Takahide; Ryu, Ilhyong

    2014-05-20

    Numerous methods for transition metal catalyzed carbonylation reactions have been established. Examples that start from aryl, vinyl, allyl, and benzyl halides to give the corresponding carboxylic acid derivatives have all been well documented. In contrast, the corresponding alkyl halides often encounter difficulty. This is inherent to the relatively slow oxidative addition step onto the metal center and subsequent β-hydride elimination which causes isomerization of the alkyl metal species. Radical carbonylation reactions can override such problems of reactivity; however, carbonylation coupled to iodine atom transfer (atom transfer carbonylation), though useful, often suffers from a slow iodine atom transfer step that affects the outcome of the reaction. We found that atom transfer carbonylation of primary, secondary, and tertiary alkyl iodides was efficiently accelerated by the addition of a palladium catalyst under light irradiation. Stereochemical studies support a mechanistic pathway based on the synergic interplay of radical and Pd-catalyzed reaction steps which ultimately lead to an acylpalladium species. The radical/Pd-combined reaction system has a wide range of applications, including the synthesis of carboxylic acid esters, lactones, amides, lactams, and unsymmetrical ketones such as alkyl alkynyl and alkyl aryl ketones. The design of unique multicomponent carbonylation reactions involving vicinal C-functionalization of alkenes, double and triple carbonylation reactions, in tandem with radical cyclization reactions, has also been achieved. Thus, the radical/Pd-combined strategy provides a solution to a longstanding problem of reactivity involving the carbonylation of alkyl halides. This novel methodology expands the breadth and utility of carbonylation chemistry over either the original radical carbonylation reactions or metal-catalyzed carbonylation reactions. PMID:24712759

  4. Synthesis of enyne and aryl vinyl sulfoxides: functionalization via Pummerer rearrangement.

    PubMed

    Souza, Frederico B; Shamim, Anwar; Argomedo, Luiz M Z; Pimenta, Daniel C; Stefani, Hélio A

    2015-11-01

    An efficient methodology for the synthesis of aryl-substituted vinyl sulfoxides through direct substitution of aryl-substituted alkynyl grignard reagents on menthyl-p-toluenesulfinate followed by Suzuki-Miyaura cross-coupling reaction has been developed. It has also been described that the reaction of alkyl-substituted and cycloalkyl-substituted alkynyl grignard reagents with menthyl-p-toluenesulfinate led to two products, i.e., alkynyl sulfoxide derivatives, as a result of substitution, and enyne sulfoxide derivatives, which resulted from substitution followed by Michael type addition. It was possible to selectively synthesize the enyne sulfoxide derivatives by changing the concentration of the grignard reagent. These alkenyl sulfoxides were transformed into the corresponding [Formula: see text]-thio aldehydes in high yields via additive Pummerer rearrangement. PMID:26232026

  5. A Durable Alternative for Proton-Exchange Membranes: Sulfonated Poly(Benzoxazole Thioether Sulfone)s

    SciTech Connect

    Zhao, Dan; Li, Jin Hui; Song, Min Kyu; Yi, Baolian; Zhang, Huamin; Liu, Meilin

    2011-02-24

    To develop a durable proton-exchange membrane (PEM) for fuel-cell applications, a series of sulfonated poly(benzoxazole thioether sulfone)s ( SPTESBOs) are designed and synthesized, with anticipated good dimensional stability (via acid–base cross linking), improved oxidative stability against free radicals (via incorporation of thioether groups), and enhanced inherent stability (via elimination of unstable end groups) of the backbone. The structures and the degree of sulfonation of the copolymers are characterized using Fourier-transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy ({sup 1}H NMR and {sup 19}F NMR). The electrochemical stabilities of the monomers are examined using cyclic voltammetry in a typical three-electrode cell configuration. The physicochemical properties of the membranes vital to fuel-cell performance are also carefully evaluated under conditions relevant to fuel-cell operation, including chemical and thermal stability, proton conductivity, solubility in different solvents, water uptake, and swelling ratio. The new membranes exhibit low dimensional change at 25°C to 90°C and excellent thermal stability up to 250°C. Upon elimination of unstable end groups, the co-polymers display enhanced chemical resistance and oxidative stability in Fenton's test. Further, the SPTESBO-HFB-60 (HFB-60=hexafluorobenzene, 60 mol% sulfone) membrane displays comparable fuel-cell performance to that of an NRE 212 membrane at 80°C under fully humidified condition, suggesting that the new membranes have the potential to be more durable but less expensive for fuel-cell applications.

  6. Serum albumin as a probe for testing the selectivity of irreversible cysteine protease inhibitors: The case of vinyl sulfones.

    PubMed

    Regazzoni, Luca; Colombo, Simone; Mazzolari, Angelica; Vistoli, Giulio; Carini, Marina

    2016-05-30

    Vinyl sulfones are used for drug design of irreversible inhibitors of cysteine proteases since they are able to alkylate cysteine thiols inside the catalytic pocket of this class of enzymes. Some authors have reported the lack of reactivity towards glutathione as sufficient evidence of the selectivity of such a mechanism. Herein, we demonstrate that some simple molecules containing a vinyl sulfone moiety are not thiol-specific alkylants since they react with some albumin nucleophiles including side chains of Cys34 and His146. Such side-reactions are not desirable for any drug candidate since they limit serum stability, bioavailability and they possibly trigger toxicity mechanisms. In silico predictions, indicate that the compounds tested share similar structural features with reported inhibitors of cysteine proteases, as well as similar poses around the main albumin nucleophiles. Altogether, the data suggest that albumin is better than glutathione for the setup of early in vitro tests probing the selectivity of cysteine protease inhibitors. PMID:26970985

  7. Silyl Radical Activation of Alkyl Halides in Metallaphotoredox Catalysis: A Unique Pathway for Cross-Electrophile Coupling.

    PubMed

    Zhang, Patricia; Le, Chi Chip; MacMillan, David W C

    2016-07-01

    A strategy for cross-electrophile coupling has been developed via the merger of photoredox and transition metal catalysis. In this report, we demonstrate the use of commercially available tris(trimethylsilyl)silane with metallaphotoredox catalysis to efficiently couple alkyl bromides with aryl or heteroaryl bromides in excellent yields. We hypothesize that a photocatalytically generated silyl radical species can perform halogen-atom abstraction to activate alkyl halides as nucleophilic cross-coupling partners. This protocol allows the use of mild yet robust conditions to construct Csp(3)-Csp(2) bonds generically via a unique cross-coupling pathway. PMID:27263662

  8. Polyimides with pendant alkyl groups

    NASA Technical Reports Server (NTRS)

    Jensen, B. J.; Young, P. R.

    1982-01-01

    The effect on selected polyimide properties when pendant alkyl groups were attached to the polymer backbone was investigated. A series of polymers were prepared using benzophenone tetracarboxylic acid dianhydride (BTDA) and seven different p-alkyl-m,p'-diaminobenzophenone monomers. The alkyl groups varied in length from C(1) (methyl) to C(9) (nonyl). The polyimide prepared from BTDA and m,p'-diaminobenzophenone was included as a control. All polymers were characterized by various chromatographic, spectroscopic, thermal, and mechanical techniques. Increasing the length of the pendant alkyl group resulted in a systematic decrease in glass transition temperature (Tg) for vacuum cured films. A 70 C decrease in Tg to 193 C was observed for the nonyl polymer compared to the Tg for the control. A corresponding systematic increase in Tg indicative of crosslinking, was observed for air cured films. Thermogravimetric analysis revealed a slight sacrifice in thermal stability with increasing alkyl length. No improvement in film toughness was observed.

  9. Radical migration of substituents of aryl groups on quinazolinones derived from N-acyl cyanamides.

    PubMed

    Larraufie, Marie-Hélène; Courillon, Christine; Ollivier, Cyril; Lacôte, Emmanuel; Malacria, Max; Fensterbank, Louis

    2010-03-31

    A newly designed radical cascade involving N-acyl cyanamides is reported. It builds on aromatic homolytic substitutions as intermediate events and leads to complex heteroaromatic structures via an unprecedented radical migration of a substituent on aryl groups of quinazolinones (hydrogen or alkyl). Mechanistic considerations are detailed, which allowed us to devise fine control over the domino processes. The latter could be predictably stopped at several stages, depending on the reaction conditions. Finally, a surgical introduction of a trifluoromethyl substituent on a quinazolinone was achieved via the reported migration. PMID:20205425

  10. Synthesis and antibacterial activities of acylide derivatives bearing an aryl-tetrazolyl chain

    PubMed Central

    Shan, Ling-Xing; Sun, Ping-Hua; Guo, Bao-Qin; Xu, Xing-Jun; Li, Zhi-Qiang; Sun, Jia-Zhi; Zhou, Shu-Feng; Chen, Wei-Min

    2014-01-01

    Seventeen acylides bearing an aryl-tetrazolyl alkyl-substituted side chain were synthesized, starting from clarithromycin, via several reactions including hydrolysis, acetylating, esterification, carbamylation, and Michael addition. The structures of all new compounds were confirmed by 1H nuclear magnetic resonance spectroscopy, 13C nuclear magnetic resonance spectroscopy, and mass spectrometry. All these synthesized acylides were evaluated for in vitro antimicrobial activities against gram-positive pathogens (Staphylococcus aureus, Staphylococcus epidermidis) and gram-negative pathogens (Pseudomonas aeruginosa, Escherichia coli), using the broth microdilution method. Results showed that compounds 10e, 10f, 10g, 10 h, 10o have good antibacterial activities. PMID:25284984

  11. Visible Light Mediated Photoredox Catalytic Arylation Reactions.

    PubMed

    Ghosh, Indrajit; Marzo, Leyre; Das, Amrita; Shaikh, Rizwan; König, Burkhard

    2016-08-16

    Introducing aryl- and heteroaryl moieties into molecular scaffolds are often key steps in the syntheses of natural products, drugs, or functional materials. A variety of cross-coupling methods have been well established, mainly using transition metal mediated reactions between prefunctionalized substrates and arenes or C-H arylations with functionalization in only one coupling partner. Although highly developed, one drawback of the established sp2-sp2 arylations is the required transition metal catalyst, often in combination with specific ligands and additives. Therefore, photoredox mediated arylation methods have been developed as alternative over the past decade. We begin our survey with visible light photo-Meerwein arylation reactions, which allow C-H arylation of heteroarenes, enones, alkenes, and alkynes with organic dyes, such as eosin Y, as the photocatalyst. A good number of examples from different groups illustrate the broad application of the reaction in synthetic transformations. While initially only photo-Meerwein arylation-elimination processes were reported, the reaction was later extended to photo-Meerwein arylation-addition reactions giving access to the photoinduced three component synthesis of amides and esters from alkenes, aryl diazonium salts, nitriles or formamides, respectively. Other substrates with redox-active leaving groups have been explored in photocatalyzed arylation reactions, such as diaryliodonium and triarylsulfonium salts, and arylsulfonyl chlorides. We discus some examples with their scope and limitations. The scope of arylation reagents for photoredox reactions was extended to aryl halides. The challenge here is the extremely negative reduction potential of aryl halides in the initial electron transfer step compared to, e.g., aryl diazonium or diaryliodonium salts. In order to reach reduction potentials over -2.0 V vs SCE two consecutive photoinduced electron transfer steps were used. The intermediary formed colored radical

  12. Copolymers of fluorinated polydienes and sulfonated polystyrene

    DOEpatents

    Mays, Jimmy W.; Gido, Samuel P.; Huang, Tianzi; Hong, Kunlun

    2009-11-17

    Copolymers of fluorinated polydienes and sulfonated polystyrene and their use in fuel cell membranes, batteries, breathable chemical-biological protective materials, and templates for sol-gel polymerization.

  13. Complete oxidation of linear alkylbenzene sulfonate by bacterial communities selected from coastal seawater.

    PubMed Central

    Sigoillot, J C; Nguyen, M H

    1992-01-01

    Anionic surfactants, especially alkylbenzene sulfonates, are discharged into marine areas in great quantities. Because of their poor biodegradability, linear alkylbenzene sulfonates accumulate in seawater and sediments. Bacterial communities that can degrade surfactants were selected from coastal seawater contaminated by urban sewage. All the isolated strains consisted of gram-negative, strictly aerobic rods or helical bacteria. Some of these, though isolated from coastal seawater, did not need sodium for growth and appeared to be related to the genera Alcaligenes and Pseudomonas. Complete surfactant biodegradation was achieved by three important steps: terminal oxidation of the alkyl chain, desulfonation, and aromatic-ring cleavage. Only a few strains were able to carry out the first two steps. The aromatic ring was then cleaved by other strains that possess very specific enzymatic activities. Finally, a number of strains grew on short acids that were end-of-metabolism products of the others. PMID:1599249

  14. Rearrangements of Cycloalkenyl Aryl Ethers.

    PubMed

    Törincsi, Mercedesz; Nagy, Melinda; Bihari, Tamás; Stirling, András; Kolonits, Pál; Novak, Lajos

    2016-01-01

    Rearrangement reactions of cycloalkenyl phenol and naphthyl ethers and the acid-catalyzed cyclization of the resulting product were investigated. Claisen rearrangement afforded 2-substituted phenol and naphthol derivatives. Combined Claisen and Cope rearrangement resulted in the formation of 4-substituted phenol and naphthol derivatives. In the case of cycloocthylphenyl ether the consecutive Claisen and Cope rearrangements were followed by an alkyl migration. The mechanism of this novel rearrangement reaction is also discussed. PMID:27104504

  15. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Boric acid, alkyl and substituted... Significant New Uses for Specific Chemical Substances § 721.1875 Boric acid, alkyl and substituted alkyl... chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  16. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Boric acid, alkyl and substituted... Significant New Uses for Specific Chemical Substances § 721.1875 Boric acid, alkyl and substituted alkyl... chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  17. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid, alkyl and substituted... Significant New Uses for Specific Chemical Substances § 721.1875 Boric acid, alkyl and substituted alkyl... chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  18. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Boric acid, alkyl and substituted... Significant New Uses for Specific Chemical Substances § 721.1875 Boric acid, alkyl and substituted alkyl... chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  19. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Boric acid, alkyl and substituted... Significant New Uses for Specific Chemical Substances § 721.1875 Boric acid, alkyl and substituted alkyl... chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  20. Alkylation and acylation of cyclotriphosphazenes.

    PubMed

    Benson, Mark A; Zacchini, Stefano; Boomishankar, Ramamoorthy; Chan, Yuri; Steiner, Alexander

    2007-08-20

    Phosphazenes (RNH)6P3N3 (R = n-propyl, isobutyl, isopropyl, cyclohexyl, tert-butyl, benzyl) are readily alkylated at ring N sites by alkyl halides forming N-alkyl phosphazenium cations. Alkylation of two ring N sites occurred after prolonged heating in the presence of methyl iodide or immediately at room temperature with methyl triflate yielding N,N'-dimethyl phosphazenium dications. Geminal dichloro derivatives Cl2(RNH)4P3N3 are methylated by methyl iodide at the ring N site adjacent to both P centers carrying four RNH groups. X-ray crystal structures showed that the alkylation of ring N sites leads to substantial elongation of the associated P-N bonds. Both N-alkyl and N,N'-dialkyl phosphazenium salts form complex supramolecular networks in the solid state via NH...X interactions. Systems carrying less-bulky RNH groups show additional NH...N bonds between N-alkyl phosphazenium ions. N-Alkyl phosphazenium halides form complexes with silver ions upon treatment with silver nitrate. Depending on the steric demand of RNH substituents, either one or both of the vacant ring N sites engage in coordination to silver ions. Treatment of (RNH)6P3N3 (R = isopropyl) with acetyl chloride and benzoyl chloride, respectively, yielded N-acyl phosphazenium ions. X-ray crystal structures revealed that elongation of P-N bonds adjacent to the acylated ring N site is more pronounced than it is in the case of N-alkylated species. Salts containing N-alkyl phosphazenium ions are stable toward water and other mild nucleophiles, while N,N'-dialkyl and N-acyl phosphazenium salts are readily hydrolyzed. The reaction of (RNH)6P3N3 with bromoacetic acid led to N-alkylation at one ring N site in addition to formation of an amide via condensation of an adjacent RNH substituent with the carboxylic acid group. The resulting bromide salt contains mono cations of composition (RNH)5P3N3CH2CONR in which a CH2-C(O) unit is embedded between a ring N and an exocyclic N site of the phosphazene. PMID

  1. Red electroluminescence of ruthenium sensitizer functionalized by sulfonate anchoring groups.

    PubMed

    Shahroosvand, Hashem; Abbasi, Parisa; Mohajerani, Ezeddin; Janghouri, Mohammad

    2014-06-28

    We have synthesized five novel Ru(ii) phenanthroline complexes with an additional aryl sulfonate ligating substituent at the 5-position [Ru(L)(bpy)2](BF4)2 (1), [Ru(L)(bpy)(SCN)2] (2), [Ru(L)3](BF4)2 (3), [Ru(L)2(bpy)](BF4)2 (4) and [Ru(L)(BPhen)(SCN)2] (5) (where L = 6-one-[1,10]phenanthroline-5-ylamino)-3-hydroxynaphthalene 1-sulfonic, bpy = 2,2'-bipyridine, BPhen = 4,7-diphenyl-1,10-phenanthroline), as both photosensitizers for oxide semiconductor solar cells (DSSCs) and light emitting diodes (LEDs). The absorption and emission maxima of these complexes red shifted upon extending the conjugation of the phenanthroline ligand. Ru phenanthroline complexes exhibit broad metal to ligand charge transfer-centered electroluminescence (EL) with a maximum near 580 nm. Our results indicated that a particular structure (2) can be considered as both DSSC and OLED devices. The efficiency of the LED performance can be tuned by using a range of ligands. Device (2) has a luminance of 550 cd m(-2) and maximum efficiency of 0.9 cd A(-1) at 18 V, which are the highest values among the five devices. The turn-on voltage of this device is approximately 5 V. The role of auxiliary ligands in the photophysical properties of Ru complexes was investigated by DFT calculation. We have also studied photovoltaic properties of dye-sensitized nanocrystalline semiconductor solar cells based on Ru phenanthroline complexes and an iodine redox electrolyte. A solar energy to electricity conversion efficiency (η) of 0.67% was obtained for Ru complex (2) under standard AM 1.5 irradiation with a short-circuit photocurrent density (Jsc) of 2.46 mA cm(-2), an open-circuit photovoltage (Voc) of 0.6 V, and a fill factor (ff) of 40%, which are all among the highest values for ruthenium sulfonated anchoring groups reported so far. Monochromatic incident photon to current conversion efficiency was 23% at 475 nm. Photovoltaic studies clearly indicated dyes with two SCN substituents yielded a higher Jsc for the

  2. Direct catalytic olefination of alcohols with sulfones.

    PubMed

    Srimani, Dipankar; Leitus, Gregory; Ben-David, Yehoshoa; Milstein, David

    2014-10-01

    The synthesis of terminal, as well as internal, olefins was achieved by the one-step olefination of alcohols with sulfones catalyzed by a ruthenium pincer complex. Furthermore, performing the reaction with dimethyl sulfone under mild hydrogen pressure provides a direct route for the replacement of alcohol hydroxy groups by methyl groups in one step. PMID:25163718

  3. N-Aryl Lactams by Regioselective Ozonation of N-Aryl Cyclic Amines

    PubMed Central

    Saliu, Francesco; Orlandi, Marco; Bruschi, Maurizio

    2012-01-01

    Ozonation of N-aryl-cyclic amines in organic solvents gave N-aryl-lactams regioselectively. In particular, 4-(4-aminophenyl)-morpolin-3-one, a key intermediate in the preparation of factor Xa inhibitors, was obtained in fair yields. The method represents an alternative approach for the lactamization of tertiary N-arylic substrates and is based on a “metal-free” introduction of the carbonyl function into the heterocyclic ring. PMID:24052840

  4. Nickel-catalyzed reductive arylation of activated alkynes with aryl iodides

    PubMed Central

    Dorn, Stephanie C. M.; Olsen, Andrew K; Kelemen, Rachel E.; Shrestha, Ruja; Weix, Daniel J.

    2015-01-01

    The direct, regioselective, and stereoselective arylation of activated alkynes with aryl iodides using a nickel catalyst and manganese reductant is described. The reaction conditions are mild (40 °C in MeOH, no acid or base) and an intermediate organomanganese reagent is unlikely. Functional groups tolerated include halides and pseudohalides, free and protected anilines, and a benzyl alcohol. Other activated alkynes including an amide and a ketone also reacted to form arylated products in good yields. PMID:26028781

  5. N-aryl lactams by regioselective ozonation of N-aryl cyclic amines.

    PubMed

    Saliu, Francesco; Orlandi, Marco; Bruschi, Maurizio

    2012-01-01

    Ozonation of N-aryl-cyclic amines in organic solvents gave N-aryl-lactams regioselectively. In particular, 4-(4-aminophenyl)-morpolin-3-one, a key intermediate in the preparation of factor Xa inhibitors, was obtained in fair yields. The method represents an alternative approach for the lactamization of tertiary N-arylic substrates and is based on a "metal-free" introduction of the carbonyl function into the heterocyclic ring. PMID:24052840

  6. Farnesyl Diphosphate Analogues with Aryl Moieties are Efficient Alternate Substrates for Protein Farnesyltransferase

    PubMed Central

    Subramanian, Thangaiah; Pais, June E.; Liu, Suxia; Troutman, Jerry M.; Suzuki, Yuta; Subramanian, Karunai Leela; Fierke, Carol; Andres, Douglas A.; Spielmann, H. Peter

    2012-01-01

    Farnesylation is an important post-translational modification essential for proper localization and function of many proteins. Transfer of the farnesyl group from farnesyl diphosphate (FPP) to proteins is catalyzed by protein farnesyltransferase (FTase). We employed a library of FPP analogues with a range of aryl groups substituting for individual isoprene moieties to examine some of the structural and electronic properties of analogue transfer to peptide catalyzed by FTase. Analysis of steady-state kinetics for modification of peptide substrates revealed that the multiple turnover activity depends on the analogue structure. Analogues where the first isoprene is replaced by a benzyl group and an analogue where each isoprene is replaced by an aryl group are good substrates. In sharp contrast with the steady-state reaction, the single turnover rate constant for dansyl-GCVLS alkylation was found to be the same for all analogues, despite the increased chemical reactivity of the benzyl analogues and the increased steric bulk of other analogues. However, the single turnover rate constant for alkylation does depend on the Ca1a2X peptide sequence. These results suggest that the isoprenoid transition state conformation is preferred over the inactive E•FPP• Ca1a2X ternary complex conformation. Furthermore, these data suggest that the farnesyl binding site in the exit groove may be significantly more selective for the farnesyl diphosphate substrate than the active site binding pocket and therefore might be a useful site for design of novel inhibitors. PMID:22989235

  7. Mild Catalytic methods for Alkyl-Alkyl Bond Formation

    SciTech Connect

    Vicic, David A

    2009-08-10

    Overview of Research Goals and Accomplishments for the Period 07/01/06 – 06/30/07: Our overall research goal is to transform the rapidly emerging synthetic chemistry involving alkyl-alkyl cross-couplings into more of a mechanism-based field so that that new, rationally-designed catalysts can be performed under energy efficient conditions. Our specific objectives for the previous year were 1) to obtain a proper electronic description of an active catalyst for alkyl-alkyl cross-coupling reactions and 2) to determine the effect of ligand structure on the rate, scope, selectivity, and functional group compatibility of C(sp3)-C(sp3) cross-coupling catalysis. We have completed both of these initial objectives and established a firm base for further studies. The specific significant achievements of the current grant period include: 1) we have performed magnetic and computational studies on (terpyridine)NiMe, an active catalyst for alkyl-alkyl cross couplings, and have discovered that the unpaired electron resides heavily on the terpyridine ligand and that the proper electronic description of this nickel complex is a Ni(II)-methyl cation bound to a reduced terpyridine ligand; 2) we have for the first time shown that alkyl halide reduction by terpyridyl nickel catalysts is substantially ligand based; 3) we have shown by isotopic labeling studies that the active catalyst (terpyridine)NiMe is not produced via a mechanism that involves the formation of methyl radicals when (TMEDA)NiMe2 is used as the catalyst precursor; 4) we have performed an extensive ligand survey for the alkyl-alkyl cross-coupling reactions and have found that electronic factors only moderately influence reactivity in the terpyridine-based catalysis and that the most dramatic effects arise from steric and solubility factors; 5) we have found that the use of bis(dialkylphosphino)methanes as ligands for nickel does not produce active catalysts for cross-coupling but rather leads to bridging hydride

  8. Synthesis and characterization of sulfonated poly(ether sulfone)s containing mesonaphthobifluorene for polymer electrolyte membrane fuel cell.

    PubMed

    Lim, Youngdon; Seo, Dongwan; Lee, Soonho; Hossain, Md Awlad; Lim, Jinseong; Lee, Sangyoung; Hong, Taehoon; Kim, Whangi

    2014-10-01

    The novel sulfonated poly(ether sulfone)s containing mesonaphthobifluorene (MNF) moiety were synthesized and characterized their properties. The prepared polymers have highly conjugated aromatic structure due to the MNF group which is an allotrope of carbon and one atom thick planar sheets of sp2-bonded carbon atoms. Poly(ether sulfone)s bearing tetraphenylethylene on polymer backbone were synthesized by polycondensation and followed intra-cyclization from tetraphenylethylene to form MNF by Friedel-craft reaction with Lewis acid (FeCl3). The sulfonation was performed selectively on MNF units with conc. sulfuric acid. The structural properties of the sulfonated polymers were investigated by 1H-NMR spectroscopy. The membranes were studied by ion exchange capacity (IEC), water uptake, and proton conductivity. The synthesized polymer electrolyte membranes showed better thermal and dimensional stabilities owing to the inducted highly conjugated aromatic structure in the polymer backbone. The water uptake of the synthesized membranes ranged from 23-52%, compared with 32.13% for Nafion 211 at 80 degrees C. The synthesized membranes exhibited proton conductivities (80 degrees C, RH 90%) of 74.6-100.4 mS/cm, compared with 102.7 mS/cm for Nafion 211. PMID:25942900

  9. Correlating electronic structure and chemical durability of sulfonated poly(arylene ether sulfone)s

    NASA Astrophysics Data System (ADS)

    Lawrence, Jimmy; Yamashita, Koichi; Yamaguchi, Takeo

    2015-04-01

    Many different proton-conducting polymeric materials have been developed for polymer electrolyte membrane fuel cells (PEMFCs). The development of perfluorosulfonic acid-based, polymer electrolyte membranes (PFSA-PEMs) was followed by aromatic hydrocarbon-based PEMs (HC-PEMs), which allow for tailored design and optimization of their molecular structures. Although many new PFSA-PEMs and HC-PEMs have shown promising proton conductivity and thermal stability, chemical degradation of these materials in an oxidizing environment remains a significant technical barrier in PEMFC development. Here, we used accelerated degradation tests and electronic structure analysis to examine the chemical stability of sulfonated poly(arylene ether sulfone) (SPES) copolymers, a highly thermally stable HC-PEM. HOMO levels, the presence of main chain-protecting steric groups, and HOMO-LUMO location along the main chain have significant effects on the chain scission modes and degradation rate of SPES copolymers. Rational design of HC-PEMs to suppress midpoint scission can open many opportunities in the development of highly robust polymer electrolytes for fuel cell and other energy storage applications.

  10. Synthesis Of [2h, 13c] And [2h3, 13c]Methyl Aryl Sulfides

    DOEpatents

    Martinez, Rodolfo A.; Alvarez, Marc A.; Silks, III, Louis A.; Unkefer, Clifford J.

    2004-03-30

    The present invention is directed to labeled compounds, [.sup.2 H.sub.1, .sup.13 C], [.sup.2 H.sub.2, .sup.13 C] and [.sup.2 H.sub.3, .sup.13 C]methyl aryl sulfides wherein the .sup.13 C methyl group attached to the sulfur of the sulfide includes exactly one, two or three deuterium atoms and the aryl group is selected from the group consisting of 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, and phenyl groups with the structure ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, and R.sub.5 are each independently, hydrogen, a C.sub.1 -C.sub.4 lower alkyl, a halogen, an amino group from the group consisting of NH.sub.2, NHR and NRR' where R and R' are each a C.sub.1 -C.sub.4 lower alkyl, a phenyl, or an alkoxy group. The present invention is also directed to processes of preparing [.sup.2 H.sub.1, .sup.13 C], [.sup.2 H.sub.2,.sup.13 C] and [.sup.2 H.sub.3, .sup.13 C]methyl aryl sulfides wherein the .sup.13 C methyl group attached to the sulfur of the sulfide includes exactly one, two or three deuterium atoms. The present invention is also directed to the labeled compounds of [.sup.2 H.sub.1, .sup.13 C]methyl iodide and [.sup.2 H.sub.2, .sup.13 C]methyl iodide.

  11. Electrophilic Metal Alkyl Chemistry in New Ligand Environments

    SciTech Connect

    Jordan, Richard F.

    2013-06-30

    The goals of this project were to design new electrophilic metal alkyl complexes and to exploit these systems in fundamental studies of olefin polymerization and other important and new catalytic reactions. A key target reaction is insertion copolymerization of olefins and polar CH2=CHX vinyl monomers such as vinyl halides and vinyl ethers. During the period covered by this report we (i) investigated the properties of ortho-alkoxy-arylphosphine ligands in Ni-based olefin polymerization catalysts, (ii) studied the synthesis of double-end-capped polyethylene using group 4 metal catalysts that contain tris-pyrazolylborate ligands, (iii) explored the ethylene insertion reactivity of group 4 metal tris-pyrazolyl-borate complexes, (iv) showed that (α-diimine)PdMe{sup +} species undergo multiple insertion of silyl vinyl ethers, (v) synthesized and explored the reactivity of base-free Ni benzyl complexes that contain ortho-phosphino-arene sulfonate ligands, (vi) established the mechanism of the reaction of vinyl chloride with (α-diimine)PdMe{sup +} catalysts, (vii) explored the role of cationic polymerization and insertion chemistry in the reactions of vinyl ethers with (α-diimine)PdMe{sup +} species, (viii) discovered a new class of self-assembled tetranuclear Pd catalysts that produce high molecular weight linear polyethylene and copolymerize ethylene and vinyl fluoride, and (ix) developed model systems that enabled investigation of cis-trans isomerization of {phosphine-sulfonate}Pd(II) complexes.

  12. Regioselective Radical Arylation of 3-Hydroxypyridines.

    PubMed

    Fürst, Michael C D; Bock, Leonard R; Heinrich, Markus R

    2016-07-01

    The titanium(III)-mediated radical arylation of 3-hydroxypyridines was found to proceed with high regioselectivity for the 2-position. Using aryldiazonium chlorides, which were prepared from the corresponding anilines, as aryl radical sources, a range of 3-hydroxy-2-phenylpyridines were obtained in moderate to good yields under simple reaction conditions. Reactions of ortho-carboxylic ester substituted phenyldiazonium salts directly provided tricyclic benzopyranopyridinones. PMID:27258367

  13. CO2 Gas Transport Property of Sulfonated Poly(Arylenen Ether Sulfone) Copolymer Membrane.

    PubMed

    Lee, Hye Jin; Kim, Deuk Ju; Nam, Sang Yong

    2015-03-01

    The effect of functional groups such as sulfuric acid group and metal ions on the CO2 gas transport property of membranes was investigated. Sulfonated poly(arylene ether sulfone) (SPAES) was prepared by direct copolymerization with a non-sulfonated monomer and sulfonated monomer. The sulfonation degree of SPAES was controlled from 0 to 50%. Metal ions such as lithium and sodium were substituted for the protons of the -SO3H group. The thermal properties, microstructure of polymer chains, and the permeability and selectivity of membranes were evaluated. The solubility coefficient of CO2 gas increased with an increase in sulfonation degree. But the diffusivity was largely decreased and the CO2/N2 selectivity of the membrane substituted for metal ions was increased. PMID:26413703

  14. Alkylation of toluene with ethanol

    SciTech Connect

    Walendziewski, J.; Trawczynski, J.

    1996-10-01

    A series of Y and ZSM-5 zeolite based catalysts was prepared. Zeolites were cation exchanged and formed with 50% of aluminum hydroxide as a binder, and the obtained catalysts were finally thermally treated. Activity tests in alkylation of toluene with ethanol were carried out in the temperature range of 325--400 C, in nitrogen or hydrogen stream, and a pressure up to 3 MPa. The feed consisted of toluene and ethanol mixed in a mole ratio 1/1 or 2/1. The obtained results showed that among the studied catalysts the highest activity in the alkylation reaction was attained by ZSM-5 zeolite based catalyst with a moderate acidity and medium silica to alumina ratio, i.e., {approximately}50. Activity and selectivity of the most active catalyst as well as conversion of the feed components were similar to those reported in other papers. The content of p-ethyltoluene in alkylation products attained ca. 60%.

  15. A biological source of oceanic alkyl nitrates

    NASA Astrophysics Data System (ADS)

    Dahl, E. E.; Lewis, C. B.; Velasco, F. L.; Escobar, C.; Kellogg, D.; Velcamp, M.

    2013-12-01

    Alkyl nitrates are an important component of reactive nitrogen in the troposphere. The oceans are a source of alkyl nitrates to the atmosphere, however the source of alkyl nitrates in the oceans is unknown. It has been demonstrated that the reaction of alkyl peroxy radicals (ROO) with nitric oxide (NO) produces alkyl nitrates in the aqueous phase. We hypothesize that alkyl nitrates may be formed by organisms through the same reaction and therefore biological production could be a source of alkyl nitrates to the troposphere. This work focuses on the production of alkyl nitrates by the diatoms Chaetoceros muelleri and Thalassiosira weisfloggi. Using chemostats, we measure alkyl nitrates formed under nitrate limited conditions. We also use triggers and inhibitors of nitric oxide formation to determine if alkyl nitrate formation is affected by changes in NO production. To date, the rates of production of alkyl nitrates in our cultures, lead us to estimate a production rate on the order of femtomolar/day for C1-C3 alkyl nitrates by diatom species in the equatorial Pacific Ocean. This suggests that diatoms may contribute to the overall ocean source of alkyl nitrates; however, it is possible that other types of phytoplankton, such as cyanobacteria, that are more abundant in the open ocean, may contribute to a greater extent.

  16. Chlorine resistant desalination membranes based on directly sulfonated poly(arylene ether sulfone) copolymers

    DOEpatents

    McGrath, James E.; Park, Ho Bum; Freeman, Benny D.

    2011-10-04

    The present invention provides a membrane, kit, and method of making a hydrophilic-hydrophobic random copolymer membrane. The hydrophilic-hydrophobic random copolymer membrane includes a hydrophilic-hydrophobic random copolymer. The hydrophilic-hydrophobic random copolymer includes one or more hydrophilic monomers having a sulfonated polyarylsulfone monomer and a second monomer and one or more hydrophobic monomers having a non-sulfonated third monomer and a fourth monomer. The sulfonated polyarylsulfone monomer introduces a sulfonate into the hydrophilic-hydrophobic random copolymer prior to polymerization.

  17. Palladium-catalyzed β-C(sp(3))-H arylation of phthaloyl alanine with hindered aryl iodides: synthesis of complex β-aryl α-amino acids.

    PubMed

    Zhang, Xuekai; He, Gang; Chen, Gong

    2016-06-28

    An efficient protocol for palladium-catalyzed β-C(sp(3))-H arylation of aliphatic carboxamides equipped with a 2-(2-pyridyl) ethylamine (PE) auxiliary was developed. The PE auxiliary is uniquely effective at facilitating the arylation of primary C(sp(3))-H bonds with sterically hindered aryl iodides. A variety of aryl iodides bearing alkoxyl, carbonyl, nitro and halogen groups on the ortho position can react with the PE-coupled phthaloyl alanine substrate in moderate to excellent yield. These reactions offer a useful solution for preparing complex β-aryl α-amino acid products from readily accessible starting materials. PMID:26781005

  18. Phosphine-alkene ligand-mediated alkyl-alkyl and alkyl-halide elimination processes from palladium(II).

    PubMed

    Tuxworth, Luke; Baiget, Lise; Phanopoulos, Andreas; Metters, Owen J; Batsanov, Andrei S; Fox, Mark A; Howard, Judith A K; Dyer, Philip W

    2012-10-28

    N-Diphenylphosphino-7-aza-benzobicyclo[2.2.1]hept-2-ene (2) behaves as a chelating phosphine-alkene ligand for Pd(0) and Pd(II), promoting direct alkyl-alkyl and indirect alkyl-halide reductive elimination reactions due to the stabilisation of the resulting bis(phosphine-alkene)Pd(0) complex. PMID:22986447

  19. Masked N-Heterocyclic Carbene-Catalyzed Alkylation of Phenols with Organic Carbonates.

    PubMed

    Lui, Matthew Y; Yuen, Alexander K L; Masters, Anthony F; Maschmeyer, Thomas

    2016-09-01

    An easily prepared masked N-heterocyclic carbene, 1,3-dimethylimidazolium-2-carboxylate (DMI-CO2 ), was investigated as a "green" and inexpensive organocatalyst for the alkylation of phenols. The process made use of various low-toxicity and renewable alkylating agents, such as dimethyl- and diethyl carbonate, in a focused microwave reactor. DMI-CO2 was found to be a very active catalyst and excellent yields of a range of aryl alkyl ethers were obtained under relatively benign conditions. The observed difference in the conversion behavior of phenol methylation, in the presence of either the carbene or 1,8-diazabicycloundec-7-ene (DBU) catalyst, was rationalized on the basis of mechanistic investigations. The primary mode of action for the N-heterocyclic carbene is nucleophilic catalysis. Activation of the dialkyl carbonate electrophile results in concomitant evolution of an organo-soluble alkoxide, which deprotonates the phenolic starting material. In contrast, DBU is initially protonated by the phenol and thus consumed. Subsequent regeneration and participation in nucleophilic catalysis only becomes significant after some phenolate alkylation occurs. PMID:27528488

  20. Linear free energy relationships and cytotoxicities of para-substituted 2-haloethyl aryl selenides and bis(2-chloroethyl) selenides.

    PubMed

    Kang, S I; Spears, C P

    1987-04-01

    Examples of a new class of alkylating agents, selenium mustards, were prepared for study of their chemical kinetic properties and cytotoxicities against human lymphoblastoid CCRF-CEM cells. In a series of para-substituted aryl 2-chloroethyl selenides, a linear free energy relationship between the first-order rate constant, k'nbp and sigma p gave a rho value of -1.3, indicating that formation of a cyclic ethylene selenonium ion is the rate-controlling step for alkylation of 4-(4-nitrobenzyl)pyridine (NBP). Consistent with the ethyleneselenonium ion pathway, rates of solvolyses were extremely sensitive to increasing water content, and a positive correlation was found between reactivity with NBP and nucleophilic selectivity (Swain-Scott s constant). The s constant, which predicts for variation in intracellular product spread, varied from 0.53 up to 0.95, equal to aliphatic nitrogen mustards. Alkylating activities based on extent of NBP alkylation, however, showed relatively low values, 8-23% of that of mechlorethamine, possibly due to hydrolysis occurring by a separate pathway from nucleophilic substitution. Reactivities and nucleophilic selectivities both showed positive correlations with cytotoxicities, suggesting that the rate and extent of alkylation of relatively strong nucleophilic centers mediate the biologic effects of these compounds. Two bifunctional selenium mustards were substantially more cytotoxic than monofunctional aromatic selenides. No additional cytotoxicity due to the selenium atom was observed, with the exception of diselenide (-SeSe-) compounds. Thus, selenium alkylating agents kinetically and biologically resemble classical, mustard-type alkylating agents. PMID:3560155

  1. Distillate fuels containing an amine salt of a sulfonic acid and a low volatility carrier fluid (PNE-554)

    SciTech Connect

    Ashcraft, T.L.; Schilowitz, A.M.; Talley, L.D.; Berlowitz, P.J.

    1993-06-01

    A distillate fuel composition is described comprising a major amount of gasoline and a minor synergistic amount of an additive combination of (a) an amine salt of a sulfonic acid wherein the amine moiety is a monoamine, a polyamine, a monoamine or a polyamine containing ether linkages, or mixtures thereof, said amine moiety containing from 2 to 100 carbon atoms and from 1 to 3 nitrogen atoms, and the sulfonic acid moiety is an alkyl benzyl sulfonic acid in which the alkyl group contains from 20 to 50 carbon atoms, and (b) a carrier fluid that is mineral oil base stock, a polyol ester, and mixtures thereof, wherein less than 10 volume % of the carrier fluid in vaporized at a temperature of 125 C., provided that the amount of component (a) in the fuel composition is from about 40 to about 1500 ppm and the amount of component (b) is from about 0.1 to about 10 times the amount of component (a).

  2. Crystal structure of zwitterionic bisimidazolium sulfonates

    NASA Astrophysics Data System (ADS)

    Kohmoto, Shigeo; Okuyama, Shinpei; Yokota, Nobuyuki; Takahashi, Masahiro; Kishikawa, Keiki; Masu, Hyuma; Azumaya, Isao

    2012-05-01

    Crystal structures of three zwitterionic bisimidazolium salts 1-3 in which imidazolium sulfonate moieties were connected with aromatic linkers, p-xylylene, 4,4'-dimethylenebiphenyl, and phenylene, respectively, were examined. The latter two were obtained as hydrates. An S-shaped molecular structure in which the sulfonate moiety was placed on the imidazolium ring was observed for 1. A helical array of hydrated water molecules was obtained for 2 while a linear array of hydrated water molecules was observed for 3.

  3. Crystal structure of phenyl 2,4,5-tri­chloro­benzene­sulfonate

    PubMed Central

    Riley, Sean; Staples, Richard J.; Biros, Shannon M.; Ngassa, Felix N.

    2016-01-01

    The title compound, C12H7Cl3O3S, was synthesized via a nucleophilic substitution reaction between phenol and 2,4,5-tri­chloro­benzene­sulfonyl chloride. The two aryl rings are oriented gauche to one another around the sulfonate S—O bond, with a C—S—O—C torsion angle of −70.68 (16)°, and the two rings are inclined to one another by 72.40 (7)°. In the crystal, mol­ecules are linked via various C—Cl⋯π inter­actions, forming ribbons propagating along [100]. Neighboring ribbons are linked by a weak C—Cl⋯π inter­action, forming layers parallel to (010). PMID:27308043

  4. The Remarkable Reactivity of Aryl Halides with Nucleophiles

    ERIC Educational Resources Information Center

    Bunnett, Joseph F.

    1974-01-01

    Discusses the reactivity of aryl halides with nucleophilic or basic reagents, including nucleophilic attacks on carbon, hydrogen, halogen, and arynes. Suggestions are made concerning revisions of the sections on aryl halide chemistry courses and the corresponding chapters in textbooks. (CC)

  5. 40 CFR 721.9892 - Alkylated urea.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylated urea. 721.9892 Section 721... Alkylated urea. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an alkylated urea (PMN P-93-1649) is subject to reporting under...

  6. 40 CFR 721.9892 - Alkylated urea.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkylated urea. 721.9892 Section 721... Alkylated urea. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an alkylated urea (PMN P-93-1649) is subject to reporting under...

  7. 40 CFR 721.9892 - Alkylated urea.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkylated urea. 721.9892 Section 721... Alkylated urea. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an alkylated urea (PMN P-93-1649) is subject to reporting under...

  8. 40 CFR 721.9892 - Alkylated urea.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkylated urea. 721.9892 Section 721... Alkylated urea. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an alkylated urea (PMN P-93-1649) is subject to reporting under...

  9. 40 CFR 721.9892 - Alkylated urea.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkylated urea. 721.9892 Section 721... Alkylated urea. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an alkylated urea (PMN P-93-1649) is subject to reporting under...

  10. Gold(I)-Catalyzed Intramolecular Hydroamination of N-Allylic,N'-Aryl Ureas to form Imidazolidin-2-ones.

    PubMed

    Li, Hao; Song, Feijie; Widenhoefer, Ross A

    2011-04-18

    Treatment of N-allylic,N'-aryl ureas with a catalytic 1:1 mixture of di-tert-butyl-o-biphenylphoshphine gold(I) chloride and silver hexafluorophosphate (1 mol %) in chloroform at room temperature led to 5-exo hydroamination to form the corresponding imidazolidin-2-ones in excellent yield. In the case of N-allylic ureas that possessed an allylic alkyl, benzyloxymethyl, or acetoxymethyl substituent, gold(I)-catalyzed 5-exo hydroamination leads to formation of the corresponding trans-3,4-disubstituted imidazolidin-2-ones in excellent yield with ≥50:1 diastereoselectivity. PMID:21709731

  11. Oil compositions containing alkyl amine or alkyl mercaptan derivatives of copolymers of an alpha olefin or an alkyl vinyl ether

    SciTech Connect

    Le, H.T.

    1990-02-13

    This patent describes an oil composition. It comprises a major amount of an oil selected from a crude oil or fuel oil and a minor amount of an alkyl amine or alkyl mercaptan derivative of an alpha olefin or alkyl vinyl ether and an unsaturated alpha, beta-dicarboxylic compound copolymer having pour point depressant ;properties. The copolymer comprising the reaction product of an alpha olefin having from about 2 to about 30 carbon atoms or mixtures of alpha olefins having from about 2 to about 30 carbon atoms or an alkyl vinyl ether or mixture of alkyl vinyl ethers.

  12. 4-Alkylated Silver-N-Heterocyclic Carbene (NHC) Complexes with Cytotoxic Effects in Leukemia Cells.

    PubMed

    Sandtorv, Alexander H; Leitch, Calum; Bedringaas, Siv Lise; Gjertsen, Bjørn Tore; Bjørsvik, Hans-René

    2015-09-01

    Computational chemistry has shown that backbone-alkylated imidazoles ought to be efficient ligands for transition metal catalysts with improved carbene-to-metal donation. In this work, such alkylated imidazoles were synthesized and complexed with silver(I) by means of an eight/nine-step synthetic pathway we devised to access a new class of biologically active silver complexes. The synthesis involves selective iodination of the imidazole backbone, followed by Sonogashira coupling to replace the backbone iodine. The installed alkyne moiety is then subjected to reductive hydrogenation with Pearlman's catalyst. The imidazole N1 atom is arylated by the palladium-catalyzed Buchwald N-arylation method. The imidazole N3 position was then methylated with methyl iodine, whereupon the synthesis was terminated by complexation of the imidazolium salt with silver(I) oxide. The synthetic pathway provided an overall yield of ≈20 %. The resulting complexes were tested in vitro against HL60 and MOLM-13 leukemic cells, two human-derived cell lines that model acute myeloid leukemia. The most active compounds exhibiting low IC50 values of 14 and 27 μM, against HL60 and MOLM-13 cells, respectively. The imidazole side chain was found to be essential for high cytotoxicity, as the imidazole complex bearing a C7 side chain at the 4-position was four- to sixfold more potent than the corresponding imidazole elaborated with a methyl group. PMID:26250720

  13. Hydrogen production by water electrolysis using tetra-alkyl-ammonium-sulfonic acid ionic liquid electrolytes

    NASA Astrophysics Data System (ADS)

    Fiegenbaum, Fernanda; Martini, Emilse M.; de Souza, Michèle O.; Becker, Márcia R.; de Souza, Roberto F.

    2013-12-01

    Triethylammonium-propanesulfonic acid tetrafluoroborate (TEA-PS·BF4) is used as an electrolyte in the water electrolysis. The electrolysis of water with this ionic conductor produces high current densities with high efficiencies, even at room temperatures. A system using TEA-PS·BF4 in an electrochemical cell with platinum electrodes has current densities (i) up to 1.77 A cm-2 and efficiencies between 93 and 99% in temperatures ranging from 25 °C to 80 °C. The activation energy observed with TEA-PS·BF4 is ca. 9.3 kJ mol-1, a low value that can be explained by the facilitation of proton transport in the organised aqueous ionic liquid media. The unexpectedly high efficiency of this system is discussed by taking into account the high conductivities associated with the Brönsted and Lewis acidity characteristics associated with these ionic conductive materials.

  14. Equilibrium and saturation coverage studies of alkyl and aryl isocyanides on powdered gold

    SciTech Connect

    Shih, K.C.; Angelici, R.J. |

    1995-07-01

    Isocyanides (C=-N-R) adsorbed from 1,2-dichloroethane(DCE) solution on powdered gold were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Concentration measurements showed that adsorption equilibrium constants decrease in the order: CNPh > CNCH{sub 2}C(O)OEt > 4-CNC{sub 6}H{sub 4}NO{sub 2} > CNBu{sup n}. This is a different order than that (CNBu{sup t} nearly equals CNBu{sup n} > CNCH{sub 2}C(O)OEt > CNPh > 4-CNC{sub 6}H{sub 4}NO{sub 2}) observed for the binding of isocyanides in the complex AuCl(C=N-R) ; this latter order indicates that the isocyanides with the highest {sigma}-donor ability bind the most strongly. At saturation coverage, the number of moles of adsorbed C=N-R per gram of Au decreases as the size of the R group increases: CNBu{sup n} > CN(c-C{sub 6}H{sub 11}) > CNBu{sup t} > 2,4,6-CNC{sub 6}H{sub 2}(Bu{sup t}){sup 3}. For the least bulky isocyanide (CNBu{sup n}), the ratio of CNBu{sup n} molecules to surface Au atoms is approximately 1/3.9. From calculated cross-sectional areas of the R groups in the isocyanides, it is estimated that two-thirds of the surface area is covered at saturation coverage for all of the isocyanides. Gold powder that is surface-oxidized by Cl{sub 2} adsorbs CNBu{sup n} but AuCl(CNBu{sup n}) desorbs into the DCE solution. 41 refs., 8 figs., 5 tabs.

  15. Unusual reactivity of nitronates with an aryl alkyl carbonate: synthesis of α-amino esters.

    PubMed

    Reddy, Golipalli Ramana; Mukherjee, Debopreeti; Chittoory, Arjun Kumar; Rajaram, Sridhar

    2014-11-21

    The monoanions of nitroalkanes are ambident nucleophiles that react with carbonate electrophiles through the oxygen atom. Products arising from reactivity at the carbon atom will yield α-nitro esters, which are precursors for α-amino esters. We demonstrate this in the reactions of nitroalkanes with benzyl phenyl carbonate and DABCO where α-nitro esters are obtained instead of nitrile oxides. The products are readily reduced to α-amino esters. This pathway could be a safe alternative to the Strecker reaction. PMID:25372506

  16. Synthesis and characterization of potassium aryl- and alkyl-substituted silylchalcogenolate ligands.

    PubMed

    Brown, Jessie L; Montgomery, Ashley C; Samaan, Christopher A; Janicke, Michael T; Scott, Brian L; Gaunt, Andrew J

    2016-06-14

    Treatment of either triphenyl(chloro)silane or tert-butyldiphenyl(chloro)silane with potassium metal in THF, followed by addition of 18-crown-6, affords [K(18-crown-6)][SiPh3] () and [K(18-crown-6)][SiPh2(t)Bu] (), respectively, as the reaction products in high yield. Compounds and were fully characterized including by multi-nuclear NMR, UV/vis and IR spectroscopies. Addition of elemental chalcogen to either or , results in facile chalcogen insertion into the potassium-silicon bond to afford the silylchalcogenolates, [K(18-crown-6)][E-SiPh2R] (E = S, R = Ph (); E = Se, R = Ph (); E = Te, R = Ph (); E = S, R = (t)Bu (); E = Se, R = (t)Bu (); E = Te, R = (t)Bu ()), in moderate to good yield. The silylchalcogenolates reported herein were characterized by multi-nuclear NMR, UV/vis and IR spectroscopies, and their solid-state molecular structures were determined by single-crystal X-ray crystallography. Importantly, the reported compounds crystallize as discrete monomers in the solid-state, a structural feature not previously observed in silylchalcogenolates, providing well-defined access routes into systematic metal complexation studies. PMID:26903261

  17. A new derivatization reagent for LC-MS/MS screening of potential genotoxic alkylation compounds.

    PubMed

    van Wijk, A M; Niederländer, H A G; Siebum, A H G; Vervaart, M A T; de Jong, G J

    2013-02-23

    A screening method for trace analysis of potentially genotoxic alkylating compounds has been developed using butyl 1-(pyridin-4-yl) piperidine 4-carboxylate (BPPC) as a new, selective pre-column derivatization reagent for their subsequent analysis by hydrophilic interaction liquid chromatography (HILIC) hyphenated with tandem mass spectrometry (LC-MS/MS). The new derivatization reagent is a modification of 4-dimethylaminopyridine (4-DMAP) previously used for the determination of potentially genotoxic compounds. By using the new reagent the screening potential was enhanced without compromising reactivity. Derivatization at a high pH value was carried out and the reaction time at 60°C was 24h to anticipate for alkyl chlorides showing to be less reactive. The new reagent was designed to obtain reagent related fragmentation of the whole reagent as well as a side group of the reagent. Collision energies for detection of alkylating components derivatized using the new reagent are shown to be significantly more universal than with 4-DMAP. Neutral loss scanning on the fragmentation related to the build in side group remedies shortcomings in the screening for alkyl halides observed when using 4-DMAP. The new approach allows for screening of alkyl halides and alkyl sulfonates at trace levels down to 1 mg kg(-1) and target analysis at about a factor of 10 lower without a significant effect of the active pharmaceutical ingredient (API) matrix. The synthesis of the reagent, investigation of reactivity, the specificity of the fragmentation of derivatives and screening conditions in MS/MS analysis are described. PMID:23245244

  18. A role for Saccharomyces cerevisiae Tpa1 protein in direct alkylation repair.

    PubMed

    Shivange, Gururaj; Kodipelli, Naveena; Monisha, Mohan; Anindya, Roy

    2014-12-26

    Alkylating agents induce cytotoxic DNA base adducts. In this work, we provide evidence to suggest, for the first time, that Saccharomyces cerevisiae Tpa1 protein is involved in DNA alkylation repair. Little is known about Tpa1 as a repair protein beyond the initial observation from a high-throughput analysis indicating that deletion of TPA1 causes methyl methane sulfonate sensitivity in S. cerevisiae. Using purified Tpa1, we demonstrate that Tpa1 repairs both single- and double-stranded methylated DNA. Tpa1 is a member of the Fe(II) and 2-oxoglutarate-dependent dioxygenase family, and we show that mutation of the amino acid residues involved in cofactor binding abolishes the Tpa1 DNA repair activity. Deletion of TPA1 along with the base excision repair pathway DNA glycosylase MAG1 renders the tpa1Δmag1Δ double mutant highly susceptible to methylation-induced toxicity. We further demonstrate that the trans-lesion synthesis DNA polymerase Polζ (REV3) plays a key role in tolerating DNA methyl-base lesions and that tpa1Δmag1revΔ3 triple mutant is extremely susceptible to methylation-induced toxicity. Our results indicate a synergism between the base excision repair pathway and direct alkylation repair by Tpa1 in S. cerevisiae. We conclude that Tpa1 is a hitherto unidentified DNA repair protein in yeast and that it plays a crucial role in reverting alkylated DNA base lesions and cytotoxicity. PMID:25381260

  19. A Role for Saccharomyces cerevisiae Tpa1 Protein in Direct Alkylation Repair*

    PubMed Central

    Shivange, Gururaj; Kodipelli, Naveena; Monisha, Mohan; Anindya, Roy

    2014-01-01

    Alkylating agents induce cytotoxic DNA base adducts. In this work, we provide evidence to suggest, for the first time, that Saccharomyces cerevisiae Tpa1 protein is involved in DNA alkylation repair. Little is known about Tpa1 as a repair protein beyond the initial observation from a high-throughput analysis indicating that deletion of TPA1 causes methyl methane sulfonate sensitivity in S. cerevisiae. Using purified Tpa1, we demonstrate that Tpa1 repairs both single- and double-stranded methylated DNA. Tpa1 is a member of the Fe(II) and 2-oxoglutarate-dependent dioxygenase family, and we show that mutation of the amino acid residues involved in cofactor binding abolishes the Tpa1 DNA repair activity. Deletion of TPA1 along with the base excision repair pathway DNA glycosylase MAG1 renders the tpa1Δmag1Δ double mutant highly susceptible to methylation-induced toxicity. We further demonstrate that the trans-lesion synthesis DNA polymerase Polζ (REV3) plays a key role in tolerating DNA methyl-base lesions and that tpa1Δmag1revΔ3 triple mutant is extremely susceptible to methylation-induced toxicity. Our results indicate a synergism between the base excision repair pathway and direct alkylation repair by Tpa1 in S. cerevisiae. We conclude that Tpa1 is a hitherto unidentified DNA repair protein in yeast and that it plays a crucial role in reverting alkylated DNA base lesions and cytotoxicity. PMID:25381260

  20. Human Skin Aryl Hydrocarbon Hydroxylase

    PubMed Central

    Bickers, David R.; Kappas, Attallah

    1978-01-01

    Coal tar products, which are widely used in treating dermatologic disease, contain numerous polycyclic aromatic hydrocarbons, including 3,4-benzo[a]pyrene (BP). BP is among the most potent environmental chemical carcinogens and is known to evoke tumors in the skin of experimental animals and perhaps also of man. In this study the effect of cutaneous application of coal tar solution (U. S. Pharmacopeia) on aryl hydrocarbon hydroxylase (AHH) activity in the skin of patients usually treated with this drug was investigated. AHH, a cytochrome P-450 dependent carcinogen-metabolizing enzyme appears to play an important role in the activation of polycyclic hydrocarbons into reactive moieties that can bind to DNA and that may directly induce cancer. Application of coal tar solution to human skin caused a two to five-fold induction of cutaneous AHH in nine subjects. In further studies, the incubation of human skin with coal tar solution in vitro also caused variable induction of cutaneous AHH. Maximum responses in both systems occurred after 24 h and enzyme activity in vitro was time- and tissue- and substrate-concentration dependent. Studies in experimental animals showed that topical application of coal tar solution caused induction of AHH in skin and, after percutaneous absorption, in liver as well. Assay of several defined constituents of coal tar for AHH induction showed that BP was the most potent inducer of AHH tested. These studies indicate that topical application of coal tar solution in doses ordinarily used in treating dermatologic disease causes induction of AHH in human skin and suggest that such induced enzymatic activity could relate to carcinogenic responses to this agent in skin or, after percutaneous absorption, in other tissues as well. PMID:711851

  1. Effects of perfluoroalkyl acids on the function of the thyroid hormone and the aryl hydrocarbon receptor.

    PubMed

    Long, Manhai; Ghisari, Mandana; Bonefeld-Jørgensen, Eva Cecilie

    2013-11-01

    Perfluoroalkyl acids (PFAAs) are perfluorinated compounds that widely exist in the environment and can elicit adverse effects including endocrine disruption in humans and animals. This study investigated the effect of seven PFAAs on the thyroid hormone (TH) system assessing the proliferation of the 3,3',5-triiodo-L-thryonine (T3)-dependent rat pituitary GH3 cells using the T-screen assay and the effect on the aryl hydrocarbon receptor (AhR) transactivation in the AhR-luciferase reporter gene bioassay. A dose-dependent impact on GH3 cells was observed in the range 1×10(-9)-1×10(-4) M: seven PFAAs (perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), and perfluorododecanoic acid (PFDoA)) inhibited the GH3 cell growth, and four PFAAs (PFOS, PFHxS, PFNA, and PFUnA) antagonized the T3-induced GH3 cell proliferation. At the highest test concentration, PFHxS showed a further increase of the T3-induced GH3 growth. Among the seven tested PFAAs, only PFDoA and PFDA elicited an activating effect on the AhR. In conclusion, PFAAs possess in vitro endocrine-disrupting potential by interfering with TH and AhR functions, which need to be taken into consideration when assessing the impact on human health. PMID:23539207

  2. Methods of making alkyl esters

    DOEpatents

    Elliott, Brian

    2010-08-03

    A method comprising contacting an alcohol, a feed comprising one or more glycerides and equal to or greater than 2 wt % of one or more free fatty acids, and a solid acid catalyst, a nanostructured polymer catalyst, or a sulfated zirconia catalyst in one or more reactors, and recovering from the one or more reactors an effluent comprising equal to or greater than about 75 wt % alkyl ester and equal to or less than about 5 wt % glyceride.

  3. PREPARATION OF ALKYL PYROPHOSPHATE EXTRACTANTS

    DOEpatents

    Levine, C.A.; Skiens, W.E.; Moore, G.R.

    1960-08-01

    A process for providing superior solvent extractants for metal recovery processes is given wherein the extractant comprises an alkyl pyrophosphoric acid ester dissolved in an organic solvent diluent. Finely divided solid P/sub 2/O/ sub 5/ is slurried in an organic solvent-diluent selected from organic solvents such as kerosene, benzene, chlorobenzene, toluene, etc. An alcohol selected from the higher alcohols having 4 to 17 carbon atoms. e.g.. hexanol-1. heptanol-3, octanol-1. 2.6-dimethyl-heptanol-4, and decanol-1, is rapidly added to the P/sub 2/O/sub 5/ slurry in the amount of about 2 moles of alcohol to 1 mole of P/sub 2/ O/sub 5/. The temperature is maintained below about 110 deg C during the course of the P/sub 2/O/sub 5/-alcohol reaction. An alkyl pyrophosphate extractant compound is formed as a consequence of the reaction process. The alkyl pyrophosphate solvent-diluent extractant phase is useful in solvent extraction metal recovery processes.

  4. Base-Free Conditions for Rhodium-Catalyzed Asymmetric Arylation To Produce Stereochemically Labile α-Aryl Ketones.

    PubMed

    Dou, Xiaowei; Lu, Yixin; Hayashi, Tamio

    2016-06-01

    The asymmetric arylation of 2,2-dialkyl cyclopent-4-ene-1,3-diones with aryl boronic acids was found to be efficiently catalyzed by a chiral diene-rhodium μ-chloro dimer, [{RhCl((R)-diene*)}2 ], in the absence of bases in toluene/H2 O to give 2,2-dialkyl 4-aryl cyclopentane-1,3-diones in high yields with high enantioselectivity. Such compounds can not be obtained with high enantiomeric purity under the standard basic conditions used for rhodium-catalyzed asymmetric arylation because the α-aryl ketone products undergo racemization under the basic conditions. PMID:27100902

  5. Synthesis of fluorescent (benzyloxycarbonylamino)(aryl)methylphosphonates.

    PubMed

    Górniak, Michał Górny Vel; Czernicka, Anna; Młynarz, Piotr; Balcerzak, Waldemar; Kafarski, Paweł

    2014-01-01

    The synthesis of a library of structurally variable aromatic esters of (benzyloxycarbonylamino)(aryl)methylphosphonic acids is described by means of the Oleksyszyn reaction. The library was enlarged by the application of a Suzuki-Miayra approach and by preparation of mixed esters. PMID:24778727

  6. Arylation and Heteroarylation of Thienylsulfonamides with Organotrifluoroborates

    PubMed Central

    2015-01-01

    A mild, practical protocol has been developed for the Suzuki cross-coupling of unprotected thienylsulfonamides from air- and bench-stable organotrifluoroborates in the absence of a protecting group on the sulfonamide nitrogen. The developed synthetic method can be applied to the preparation of various arylated and heteroarylated thienylsulfonamides under conditions that are tolerant of a broad range of functional groups. PMID:25019222

  7. Simulation study of sulfonate cluster swelling in ionomers

    NASA Astrophysics Data System (ADS)

    Allahyarov, Elshad; Taylor, Philip L.; Löwen, Hartmut

    2009-12-01

    We have performed simulations to study how increasing humidity affects the structure of Nafion-like ionomers under conditions of low sulfonate concentration and low humidity. At the onset of membrane hydration, the clusters split into smaller parts. These subsequently swell, but then maintain constant the number of sulfonates per cluster. We find that the distribution of water in low-sulfonate membranes depends strongly on the sulfonate concentration. For a relatively low sulfonate concentration, nearly all the side-chain terminal groups are within cluster formations, and the average water loading per cluster matches the water content of membrane. However, for a relatively higher sulfonate concentration the water-to-sulfonate ratio becomes nonuniform. The clusters become wetter, while the intercluster bridges become drier. We note the formation of unusual shells of water-rich material that surround the sulfonate clusters.

  8. Cu sbnd Al sbnd Fe layered double hydroxides with CO32- and anionic surfactants with different alkyl chains in the interlayer

    NASA Astrophysics Data System (ADS)

    Trujillano, Raquel; Holgado, María Jesús; González, José Luis; Rives, Vicente

    2005-08-01

    Layered double hydroxides (LDHs), with the hydrotalcite-like structure containing Cu(II), Al(III) and Fe(III) in the layers, and different alkyl sulfonates in the interlayer, have been prepared and characterized by powder X-ray diffraction, FT-IR spectroscopy, differential thermal analysis and thermogravimetric analysis. Pure crystalline phases have been obtained in all cases. Upon heating, combustion of the organic chain takes place at lower temperature than the corresponding sodium salts.

  9. Design, Synthesis, and Structure--Activity Relationship of New 2-Aryl-3,4-dihydro-β-carbolin-2-ium Salts as Antifungal Agents.

    PubMed

    Hou, Zhe; Zhu, Li-Fei; Yu, Xin-chi; Sun, Ma-Qiang; Miao, Fang; Zhou, Le

    2016-04-13

    Twenty-two 2-aryl-9-methyl-3,4-dihydro-β-carbolin-2-ium bromides along with four 9-demethylated derivatives were synthesized and characterized by spectroscopic analysis. By using the mycelium growth rate method, the compounds were evaluated for antifungal activities in vitro against six plant pathogenic fungi, and structure-activity relationships (SAR) were derived. Almost all of the compounds showed obvious inhibition activity on each of the fungi at 150 μM. For all of the fungi, 10 of the compounds showed average inhibition rates of >80% at 150 μM, and most of their EC50 values were in the range of 2.0-30.0 μM. SAR analysis showed that the substitution pattern of the N-aryl ring significantly influences the activity; N9-alkylation improves the activity, whereas aromatization of ring-C reduces the activity. It was concluded that the present research provided a series of new 2-aryl-9-alkyl-3,4-dihydro-β-carbolin-2-iums with excellent antifungal potency and structure optimization design for the development of new carboline antifungal agents. PMID:27004437

  10. 40 CFR 721.10035 - Alkylbenzene sulfonate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkylbenzene sulfonate (generic). 721... Substances § 721.10035 Alkylbenzene sulfonate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkylbenzene sulfonate...

  11. 40 CFR 721.10035 - Alkylbenzene sulfonate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylbenzene sulfonate (generic). 721... Substances § 721.10035 Alkylbenzene sulfonate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkylbenzene sulfonate...

  12. 21 CFR 173.395 - Trifluoromethane sulfonic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Trifluoromethane sulfonic acid. 173.395 Section 173... CONSUMPTION Specific Usage Additives § 173.395 Trifluoromethane sulfonic acid. Trifluoromethane sulfonic acid... acid) may safely be used in the production of cocoa butter substitute from palm oil...

  13. 21 CFR 173.395 - Trifluoromethane sulfonic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Trifluoromethane sulfonic acid. 173.395 Section... HUMAN CONSUMPTION Specific Usage Additives § 173.395 Trifluoromethane sulfonic acid. Trifluoromethane sulfonic acid has the empirical formula CF3SO3H (CAS Reg. No. 1493-13-6). The catalyst...

  14. 40 CFR 721.1625 - Alkylbenzene sulfonate, amine salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkylbenzene sulfonate, amine salt... Substances § 721.1625 Alkylbenzene sulfonate, amine salt. Link to an amendment published at 79 FR 34636, June... substance identified generically as alkylbenzene sulfonate, amine salt (PMN P-90-456) is subject...

  15. Highly Enantioselective Formation of α-Allyl-α-Arylcyclopentanones via Pd-Catalysed Decarboxylative Asymmetric Allylic Alkylation.

    PubMed

    Akula, Ramulu; Doran, Robert; Guiry, Patrick J

    2016-07-11

    A highly enantioselective Pd-catalysed decarboxylative asymmetric allylic alkylation of cyclopentanone derived α-aryl-β-keto esters employing the (R,R)-ANDEN-phenyl Trost ligand has been developed. The product (S)-α-allyl-α-arylcyclopentanones were obtained in excellent yields and enantioselectivities (up to >99.9 % ee). This represents one of the most highly enantioselective formations of an all-carbon quaternary stereogenic center reported to date. This reaction was demonstrated on a 4.0 mmol scale without any deterioration of enantioselectivity and was exploited as the key enantioselective transformation in an asymmetric formal synthesis of the natural product (+)-tanikolide. PMID:27191198

  16. Time trends of perfluorinated alkyl acids in serum from Danish pregnant women 2008-2013.

    PubMed

    Bjerregaard-Olesen, Christian; Bach, Cathrine C; Long, Manhai; Ghisari, Mandana; Bossi, Rossana; Bech, Bodil H; Nohr, Ellen A; Henriksen, Tine B; Olsen, Jørn; Bonefeld-Jørgensen, Eva C

    2016-05-01

    We aimed to estimate the levels and time trends of perfluorinated alkyl acids (PFAAs) in serum of 1533 Danish pregnant nulliparous women between 2008 and 2013. The selection criterion of only including nulliparous women was chosen to avoid confounding from parity. The serum samples were analyzed for sixteen PFAAs using solid phase extraction and liquid chromatography tandem mass spectrometry (LC-MS/MS). We investigated the time trends for seven PFAAs, which were detected in more than 50% of the samples: perfluorohexane sulfonate (PFHxS), perfluoroheptane sulfonate (PFHpS), perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnA). We found that the serum levels of all seven PFAAs decreased during the period from 2008 to 2013; on average PFHxS decreased with 7.0% per year, PFHpS with 14.8%, PFOS with 9.3%, PFOA with 9.1%, PFNA with 6.2%, PFDA with 6.3%, and PFUnA with 7.1% per year. Adjustment for maternal age, body mass index (BMI), educational level and gestational age at blood sampling did not change the time trends much. To our knowledge, we are the first to report decreasing trends of PFNA, PFDA and PFUnA since year 2000, thereby indicating that the phase-out of these compounds are beginning to show an effect on human serum levels. PMID:26891270

  17. Multimetallic catalysed cross-coupling of aryl bromides with aryl triflates

    NASA Astrophysics Data System (ADS)

    Ackerman, Laura K. G.; Lovell, Matthew M.; Weix, Daniel J.

    2015-08-01

    The advent of transition-metal catalysed strategies for forming new carbon-carbon bonds has revolutionized the field of organic chemistry, enabling the efficient synthesis of ligands, materials, and biologically active molecules. In cases where a single metal fails to promote a selective or efficient transformation, the synergistic cooperation of two distinct catalysts--multimetallic catalysis--can be used instead. Many important reactions rely on multimetallic catalysis, such as the Wacker oxidation of olefins and the Sonogashira coupling of alkynes with aryl halides, but this approach has largely been limited to the use of metals with distinct reactivities, with only one metal catalyst undergoing oxidative addition. Here, we demonstrate that cooperativity between two group 10 metal catalysts--(bipyridine)nickel and (1,3-bis(diphenylphosphino)propane)palladium--enables a general cross-Ullmann reaction (the cross-coupling of two different aryl electrophiles). Our method couples aryl bromides with aryl triflates directly, eliminating the use of arylmetal reagents and avoiding the challenge of differentiating between multiple carbon-hydrogen bonds that is required for direct arylation methods. Selectivity can be achieved without an excess of either substrate and originates from the orthogonal reactivity of the two catalysts and the relative stability of the two arylmetal intermediates. While (1,3-bis(diphenylphosphino)propane)palladium reacts preferentially with aryl triflates to afford a persistent intermediate, (bipyridine)nickel reacts preferentially with aryl bromides to form a transient, reactive intermediate. Although each catalyst forms less than 5 per cent cross-coupled product in isolation, together they are able to achieve a yield of up to 94 per cent. Our results reveal a new method for the synthesis of biaryls, heteroaryls, and dienes, as well as a general mechanism for the selective transfer of ligands between two metal catalysts. We anticipate that this

  18. Sulfonated Polymerized Ionic Liquid Block Copolymers.

    PubMed

    Meek, Kelly M; Elabd, Yossef A

    2016-07-01

    The successful synthesis of a new diblock copolymer, referred to as sulfonated polymerized ionic liquid (PIL) block copolymer, poly(SS-Li-b-AEBIm-TFSI), is reported, which contains both sulfonated blocks (sulfonated styrene: SS) and PIL blocks (1-[(2-acryloyloxy)ethyl]-3-butylimidazolium: AEBIm) with both mobile cations (lithium: Li(+) ) and mobile anions (bis(trifluoromethylsulfonyl)imide: TFSI(-) ). Synthesis consists of polymerization via reversible addition-fragmentation chain transfer, followed by post-functionalization reactions to covalently attach the imidazolium cations and sulfonic acid anions to their respective blocks, followed by ion exchange metathesis resulting in mobile Li(+) cations and mobile TFSI(-) anions. Solid-state films containing 1 m Li-TFSI salt dissolved in ionic liquid result in an ion conductivity of >1.5 mS cm(-1) at 70 °C, where small-angle X-ray scattering data indicate a weakly ordered microphase-separated morphology. These results demonstrate a new ion-conducting block copolymer containing both mobile cations and mobile anions. PMID:27125600

  19. Perfluorooctane sulfonate (PFOS) depletion in beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perfluorooctane sulfonate (PFOS) is an industrial chemical that is used as a surfactant in several manufactured consumer products but is also a breakdown product from other chemical surfactants. As a result of its extensive use, PFOS is ubiquitous in the environment and is often detected in biosoli...

  20. Toxicity of pyrolysis gases from polyether sulfone

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Olcomendy, E. M.

    1979-01-01

    A sample of polyether sulfone was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. Animal response times were relatively short at pyrolysis temperatures of 600 to 800 C, with death occurring within 6 min. The principal toxicant appeared to be a compound other than carbon monoxide.

  1. Phase Behavior of Symmetric Sulfonated Block Copolymers

    SciTech Connect

    Park, Moon Jeong; Balsara, Nitash P.

    2008-08-21

    Phase behavior of poly(styrenesulfonate-methylbutylene) (PSS-PMB) block copolymers was studied by varying molecular weight, sulfonation level, and temperature. Molecular weights of the copolymers range from 2.9 to 117 kg/mol. Ordered lamellar, gyroid, hexagonally perforated lamellae, and hexagonally packed cylinder phases were observed in spite of the fact that the copolymers are nearly symmetric with PSS volume fractions between 0.45 and 0.50. The wide variety of morphologies seen in our copolymers is inconsistent with current theories on block copolymer phase behavior such as self-consistent field theory. Low molecular weight PSS-PMB copolymers (<6.2 kg/mol) show order-order and order-disorder phase transitions as a function of temperature. In contrast, the phase behavior of high molecular weight PSS-PMB copolymers (>7.7 kg/mol) is independent of temperature. Due to the large value of Flory-Huggins interaction parameter, x, between the sulfonated and non-sulfonated blocks, PSS-PMB copolymers with PSS and PMB molecular weights of 1.8 and 1.4 kg/mol, respectively, show the presence of an ordered gyroid phase with a 2.5 nm diameter PSS network. A variety of methods are used to estimate x between PSS and PMB chains as a function of sulfonation level. Some aspects of the observed phase behavior of PSS-PMB copolymers can be rationalized using x.

  2. Secondary recovery process utilizing sulfonated polyphenols

    SciTech Connect

    Hunter, W.D.

    1980-10-07

    Hydrocarbons are recovered from subterranean formations by injecting into a hydrocarbon bearing formation via an injection well a fluid comprising water containing a small amount of a water-soluble, sulfonated, ethoxylated polyphenol, forcing the said fluid through the formation and recovering hydrocarbons through a production well. The fluids employed may, if desired, contain an alkaline agent such as sodium hydroxide.

  3. Functionalization of immunostimulating complexes (ISCOMs) with lipid vinyl sulfones and their application in immunological techniques and therapy

    PubMed Central

    Cruz-Bustos, Teresa; González-González, Gloria; Morales-Sanfrutos, Julia; Megía-Fernández, Alicia; Santoyo-González, Francisco; Osuna, Antonio

    2012-01-01

    Background Immunostimulating complexes (ISCOM)-type nanocapsules have been functionalized with lipid vinyl sulfones that anchor to them via the hydrophobic zone of their structure and can be charged with pharmacologically active molecules or macromolecules. These functionalized nanocapsules can incorporate protein A and bind to G immunoglobulins (IgGs) to make vehicles directed at the surface antigens of infectious agents, tumor cells, or receptor cells and deliver the encapsulated molecules in a highly specific way. They may be of particular use in pharmacological treatments with highly toxic molecules that should not be used in solution whenever it can be avoided. When bound to antibodies they can be used in biological processes that require the delivery or presentation of macromolecules to certain specific cells, in immunization processes for instance, or in diagnostic immunological techniques, as they are able to transport both the secondary antibodies and the reaction labels. Methods and results We describe the preparation of ISCOMs, the binding to the ISCOMS of newly synthesized compounds composed of chain alkyl vinyl sulfone, and the subsequent binding of the vinyl-sulfone compounds to IgGs. Within this context, a compound deriving from cholesterol functionalized with vinyl sulfone and used together with cholesterol in varying proportions has been linked to the structure of the ISCOMs and bound to protein A–IgG. This functionalization in no way altered the form or structure of the ISCOMs and allowed the nanocapsules carrying the specific IgGs to bind to forms of Trypanosoma cruzi against which antibodies had been developed. The fact that functionalized ISCOMs containing antibodies could deliver actinomycin D directly to the parasite meant that the effective dose of the antibiotic could be reduced very significantly. Conclusion We have developed ISCOM-type nanocapsules functionalized with lipid vinyl sulfone capable of anchoring to the surface of functional

  4. 40 CFR 721.8673 - [(Disubstituted phenyl)]azo dihydro hydroxy alkyl oxo alkyl-substituted-pyridines (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false azo dihydro hydroxy alkyl oxo alkyl... Significant New Uses for Specific Chemical Substances § 721.8673 azo dihydro hydroxy alkyl oxo alkyl...) The chemical substances identified generically as azo dihydro hydroxy alkyl oxo...

  5. 40 CFR 721.8673 - [(Disubstituted phenyl)]azo dihydro hydroxy alkyl oxo alkyl-substituted-pyridines (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false azo dihydro hydroxy alkyl oxo alkyl... Significant New Uses for Specific Chemical Substances § 721.8673 azo dihydro hydroxy alkyl oxo alkyl...) The chemical substances identified generically as azo dihydro hydroxy alkyl oxo...

  6. 40 CFR 721.8673 - [(Disubstituted phenyl)]azo dihydro hydroxy alkyl oxo alkyl-substituted-pyridines (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false azo dihydro hydroxy alkyl oxo alkyl... Significant New Uses for Specific Chemical Substances § 721.8673 azo dihydro hydroxy alkyl oxo alkyl...) The chemical substances identified generically as azo dihydro hydroxy alkyl oxo...

  7. Ru-Catalyzed C–H Arylation of Fluoroarenes with Aryl Halides

    PubMed Central

    2016-01-01

    Although the ruthenium-catalyzed C–H arylation of arenes bearing directing groups with haloarenes is well-known, this process has never been achieved in the absence of directing groups. We report the first example of such a process and show that unexpectedly the reaction only takes place in the presence of catalytic amounts of a benzoic acid. Furthermore, contrary to other transition metals, the arylation site selectivity is governed by both electronic and steric factors. Stoichiometric and NMR mechanistic studies support a catalytic cycle that involves a well-defined η6-arene-ligand-free Ru(II) catalyst. Indeed, upon initial pivalate-assisted C–H activation, the aryl-Ru(II) intermediate generated is able to react with an aryl bromide coupling partner only in the presence of a benzoate additive. In contrast, directing-group-containing substrates (such as 2-phenylpyridine) do not require a benzoate additive. Deuterium labeling and kinetic isotope effect experiments indicate that C–H activation is both reversible and kinetically significant. Computational studies support a concerted metalation–deprotonation (CMD)-type ruthenation mode and shed light on the unusual arylation regioselectivity. PMID:26942551

  8. Ru-Catalyzed C-H Arylation of Fluoroarenes with Aryl Halides.

    PubMed

    Simonetti, Marco; Perry, Gregory J P; Cambeiro, Xacobe C; Juliá-Hernández, Francisco; Arokianathar, Jude N; Larrosa, Igor

    2016-03-16

    Although the ruthenium-catalyzed C-H arylation of arenes bearing directing groups with haloarenes is well-known, this process has never been achieved in the absence of directing groups. We report the first example of such a process and show that unexpectedly the reaction only takes place in the presence of catalytic amounts of a benzoic acid. Furthermore, contrary to other transition metals, the arylation site selectivity is governed by both electronic and steric factors. Stoichiometric and NMR mechanistic studies support a catalytic cycle that involves a well-defined η(6)-arene-ligand-free Ru(II) catalyst. Indeed, upon initial pivalate-assisted C-H activation, the aryl-Ru(II) intermediate generated is able to react with an aryl bromide coupling partner only in the presence of a benzoate additive. In contrast, directing-group-containing substrates (such as 2-phenylpyridine) do not require a benzoate additive. Deuterium labeling and kinetic isotope effect experiments indicate that C-H activation is both reversible and kinetically significant. Computational studies support a concerted metalation-deprotonation (CMD)-type ruthenation mode and shed light on the unusual arylation regioselectivity. PMID:26942551

  9. Direct Intermolecular Aniline ortho-Arylation via Benzyne Intermediates

    PubMed Central

    Truong, Thanh

    2012-01-01

    A method for direct, transition-metal-free ortho-arylation of anilines by aryl chlorides, bromides, fluorides, and triflates has been developed. This methodology provides the most direct approach to 2-arylanilines since no protecting or directing groups on nitrogen are required. The arylation is functional-group tolerant, with alkene, ether, trifluoromethyl, dimethylamino, carbonyl, chloro, and cyano functionalities tolerated. Phenylation of enantiopure binaphthyldiamine affords a product with >99% ee. PMID:23148679

  10. Palladium-Catalyzed Synthesis of N-Aryl Carbamates

    PubMed Central

    Vinogradova, Ekaterina V.; Park, Nathaniel H.; Fors, Brett P.; Buchwald, Stephen L.

    2013-01-01

    An efficient synthesis of aryl carbamates was achieved by introducing alcohols into the reaction of palladium-catalyzed cross-coupling of ArX (X = Cl, OTf) with sodium cyanate. The use of aryl triflates as electrophilic components in this transformation allowed for an expanded substrate scope for direct synthesis of aryl isocyanates. This methodology provides direct access to major carbamate protecting groups, S-thiocarbamates, and diisocyanate precursors to polyurethane materials. PMID:23441814

  11. Composite proton exchange membrane based on sulfonated organic nanoparticles

    NASA Astrophysics Data System (ADS)

    Pitia, Emmanuel Sokiri

    As the world sets its sight into the future, energy remains a great challenge. Proton exchange membrane (PEM) fuel cell is part of the solution to the energy challenge because of its high efficiency and diverse application. The purpose of the PEM is to provide a path for proton transport and to prevent direct mixing of hydrogen and oxygen at the anode and the cathode, respectively. Hence, PEMs must have good proton conductivity, excellent chemical stability, and mechanical durability. The current state-of-the-art PEM is a perfluorosulfonate ionomer, Nafion®. Although Nafion® has many desirable properties, it has high methanol crossover and it is expensive. The objective of this research was to develop a cost effective two-phase, composite PEM wherein a dispersed conductive organic phase preferentially aligned in the transport direction controls proton transport, and a continuous hydrophobic phase provides mechanical durability to the PEM. The hypothesis that was driving this research was that one might expect better dispersion, higher surface to volume ratio and improved proton conductivity of a composite membrane if the dispersed particles were nanometer in size and had high ion exchange capacity (IEC, = [mmol sulfonic acid]/gram of polymer). In view of this, considerable efforts were employed in the synthesis of high IEC organic nanoparticles and fabrication of a composite membrane with controlled microstructure. High IEC, ~ 4.5 meq/g (in acid form, theoretical limit is 5.4 meq/g) nanoparticles were achieved by emulsion copolymerization of a quaternary alkyl ammonium (QAA) neutralized-sulfonated styrene (QAA-SS), styrene, and divinylbenzene (DVB). The effects of varying the counterion of the sulfonated styrene (SS) monomer (alkali metal and QAA cations), SS concentration, and the addition of a crosslinking agent (DVB) on the ability to stabilize the nanoparticles to higher IECs were assessed. The nanoparticles were ion exchanged to acid form. The extent of ion

  12. Occupational asthma due to alkyl cyanoacrylate

    SciTech Connect

    Nakazawa, T. )

    1990-08-01

    A case of bronchial asthma induced by occupational exposure to alkyl cyanoacrylate, an adhesive, occurred in an assembly operation. Provocative exposure testing induced immediate and delayed asthmatic responses. Alkyl cyanoacrylate seemed to act as an allergen or as an irritant, resulting in the development of asthma.

  13. Stabilized dialkyl aluminum complexes as alkylating agents

    SciTech Connect

    Blum, J.; Baidossi, W.; Rosenfeld, A.

    1995-12-31

    Although trialkylaluminum derivatives are widely used as Ziegler-Natta polymerization co-catalysts, their application as routine alkylating agents is limited owing to their pyrophoric nature. The authors have now found that substitution of one of the alkyl moieties by a chelating group reduces the sensitivity of the organoaluminum compounds to air, and enables one to utilize them under normal laboratory conditions.

  14. Environmental exposure to N-aryl compounds

    SciTech Connect

    Guerin, M.R.; Buchanan, M.V.

    1987-01-01

    N-aryl compounds are well-known occupational exposure hazards but are relatively unstudied as an environmental exposure problem. Coal-derived liquid fuels and environmental tobacco smoke are examples of materials potentially leading to significant environmental exposures to aryl amines. Integrated chemical class separation and bacterial mutagenicity testing identified primary aromatic amines as the major contributors to the mutagenicities of crude coal liquids. Studies of sidestream cigarette smoke chemistry show that alkaline constituents of cigarette smoke are preferentially released into the environment as compared to that drawn into the mouth by the smoker. Two to ten times the quantity of aromatic amines are released in the sidestream smoke on a per cigarette basis. Quantities of the more mutagenic and carcinogenic multi-ring aryl amines in both coal liquids and in cigarette smoke are very small and they are accompanied by a wide variety of related compounds. Chemical ionization mass spectrometric methods have been developed to distinguish between closely related amines to facilitate their identification and quantitation at trace levels.

  15. Palladium-Catalyzed Arylation of Fluoroalkylamines

    PubMed Central

    Brusoe, Andrew T.; Hartwig, John F.

    2015-01-01

    We report the synthesis of fluorinated anilines by palladium-catalyzed coupling of fluoroalkylamines with aryl bromides and aryl chlorides. The products of these reactions are valuable because anilines typically require the presence of an electron-withdrawing substituent on nitrogen to suppress aerobic or metabolic oxidation, and the fluoroalkyl groups have steric properties and polarity distinct from those of more common electron-withdrawing amide and sulfonamide units. The fluoroalkylaniline products are unstable under typical conditions for C–N coupling reactions (heat and strong base). However, the reactions conducted with the weaker base KOPh, which has rarely been used in cross-coupling to form C–N bonds, occurred in high yield in the presence of a catalyst derived from commercially available AdBippyPhos and [Pd(allyl)Cl]2. Under these conditions, the reactions occur with low catalyst loadings (<0.50 mol % for most substrates) and tolerate the presence of various functional groups that react with the strong bases that are typically used in Pd-catalyzed C–N cross-coupling reactions of aryl halides. The resting state of the catalyst is the phenoxide complex, (BippyPhosPd(Ar)OPh); due to the electron-withdrawing property of the fluoroalkyl substituent, the turnover-limiting step of the reaction is reductive elimination to form the C–N bond. PMID:26065341

  16. Formation of 2,4,5-triaryl-4,5-dihydro-1 H-imidazoles, ( 1), from aryl aldehydes. Crystal structures of cis-( 1: aryl = pyridin-2-yl), { trans-[( 1: aryl = pyridin-2-yl)H] +[OAc] -·3H 2O}, { cis-[ 1: aryl = thien-2-yl]·0.5H 2O} and trans-( 1: aryl = thien-2-yl)

    NASA Astrophysics Data System (ADS)

    Fernandes, Christiane; Horn, Adolfo; Howie, R. Alan; Schripsema, Jan; Skakle, Janet M. S.; Wardell, James L.

    2007-06-01

    The preparations of cis-2,4,5-triaryl-4,5-dihydro-1 H-imidazoles, (aryl = thien-2-yl or pyridin-2-yl) from aryl aldehydes, ammonium chloride and triethylamine in methanol, and their conversions to the trans-isomers are reported. Crystal structures of cis-( 1: aryl = pyridin-2-yl), cis-[ 1: aryl = thien-2-yl·0.5H 2O], trans-( 1: aryl = thien-2-yl), and trans-{[( 1: aryl = pyridin-2-yl)H] +[OAc] -·3H 2O}, have been determined and compared with related structures.

  17. Enantioselective Nucleophile-Catalyzed Synthesis of Tertiary Alkyl Fluorides via the α-Fluorination of Ketenes: Synthetic and Mechanistic Studies

    PubMed Central

    2015-01-01

    The catalytic asymmetric synthesis of alkyl fluorides, particularly α-fluorocarbonyl compounds, has been the focus of substantial effort in recent years. While significant progress has been described in the formation of enantioenriched secondary alkyl fluorides, advances in the generation of tertiary alkyl fluorides have been more limited. Here, we describe a method for the catalytic asymmetric coupling of aryl alkyl ketenes with commercially available N-fluorodibenzenesulfonimide (NFSI) and C6F5ONa to furnish tertiary α-fluoroesters. Mechanistic studies are consistent with the hypothesis that the addition of an external nucleophile (C6F5ONa) is critical for turnover, releasing the catalyst (PPY*) from an N-acylated intermediate. The available data can be explained by a reaction pathway wherein the enantioselectivity is determined in the turnover-limiting transfer of fluorine from NFSI to a chiral enolate derived from the addition of PPY* to the ketene. The structure and the reactivity of the product of this proposed elementary step, an α-fluoro-N-acylpyridinium salt, have been examined. PMID:24922581

  18. Fluorodecarboxylation for the Synthesis of Trifluoromethyl Aryl Ethers.

    PubMed

    Zhang, Qing-Wei; Brusoe, Andrew T; Mascitti, Vincent; Hesp, Kevin D; Blakemore, David C; Kohrt, Jeffrey T; Hartwig, John F

    2016-08-01

    The synthesis of mono-, di-, and trifluoromethyl aryl ethers by fluorodecarboxylation of the corresponding carboxylic acids is reported. AgF2 induces decarboxylation of aryloxydifluoroacetic acids, and AgF, either generated in situ or added separately, serves as a source of fluorine to generate the fluorodecarboxylation products. The addition of 2,6-difluoropyridine increased the reactivity of AgF2 , thereby increasing the range of functional groups and electronic properties of the aryl groups that are tolerated. The reaction conditions used for the formation of trifluoromethyl aryl ethers also served to form difluoromethyl and monofluoromethyl aryl ethers. PMID:27384710

  19. Palladium-Catalyzed Zinc-Amide-Mediated C-H Arylation of Fluoroarenes and Heteroarenes with Aryl Sulfides.

    PubMed

    Otsuka, Shinya; Yorimitsu, Hideki; Osuka, Atsuhiro

    2015-10-12

    C-H arylation of polyfluoroarenes and heteroarenes with aryl sulfides proceeds smoothly with the aid of a palladium-N-heterocyclic carbene catalyst. A bulky zinc amide, TMPZnCl⋅LiCl, plays a key role as an effective base to generate the corresponding arylzinc species in situ. This arylation protocol is practically much easier to perform than our previous method, which necessitates preparation of the arylzinc reagents in advance from the corresponding aryl halides. Aryl sulfides that are prepared through sulfur-specific reactions, such as SN Ar sulfanylation and extended Pummerer reactions, undergo this direct arylation, offering interesting transformations that are otherwise difficult to achieve with conventional halogen-based organic synthesis. PMID:26235212

  20. Sulfonated nanoporous colloidal films and membranes

    NASA Astrophysics Data System (ADS)

    Smith, Joanna Jane

    The objective of this thesis is to describe the preparation and investigation of a new class of proton-conducting membrane materials, namely, nanoporous colloidal membranes whose proton conductivity results from the nanopore surface modification with organic molecules carrying acid functionalities. Both the proton transport and ion transport were studied in nanoporous silica colloidal crystals that were surface modified with sulfonic groups. First, the transport of ions was studied through sulfonated silica colloidal films that were supported on platinum electrodes using cyclic voltammetry. The surface of self-assembled nanoporous silica colloidal crystalline films was sulfonated using 1,3-propanesultone. We found that the flux of anions through the sulfonated colloidal films is reduced, while the flux of cations is increased, compared to the unmodified colloidal films. Second, the proton transport in free-standing assemblies of surface-sulfonated silica nanospheres, either randomly packed or self-assembled into a close-packed arrangement, were studied. It was demonstrated that colloidal assemblies prepared using surface-sulfonated silica nanospheres posses proton conductivity that depends on the ordering of the material, temperature and relative humidity. Based on the comparison between the close-packed and disordered assemblies made of the same spheres, we conclude that the increase in structural organization of the self-assembled colloidal materials leads to increased proton conductivity and better water retention. Next free-standing colloidal membranes with a relatively large area and no mechanical defects were prepared by sintering silica colloidal films. The sintered membranes were then surface rehydroxylated, which restores the surface silanol groups, and then can be chemically modified. Finally, sintered self-assembled nanoporous silica colloidal crystals were modified with poly(sulfopropyl-methacrylate) (pSPM) and poly(stryrenesulfonic acid) (pSSA) brushes

  1. Alkylating reactivity and herbicidal activity of chloroacetamides.

    PubMed

    Jablonkai, Istvan

    2003-04-01

    The relationship between S- and N-alkylating reactivity and herbicidal activity within a series of chloroacetamides, including several commercial herbicides and newly synthesised analogues was studied. The S-alkylating reactivity of selected chloroacetamides, as well as those of atrazine and chlorfenprop-methyl, was determined by in vitro GSH conjugation at a ratio of GSH to alkylating agent of 25:1. A spectrophotometric reaction using 4-(4-nitrobenzyl)pyridine was used to characterise the N-alkylating reactivity of the chemicals. Our results indicate that a reduced level of N-alkylating reactivity correlates with an improved herbicidal efficacy at a practical rate. However, the phytoxicity of the molecules is not simply dependent on chemical reactivities, but strictly related to the molecular structure, indicating that lipophilicity, uptake, mobility and induction of detoxifying enzymes may also be decisive factors in the mode of action. PMID:12701706

  2. C-Alkylation by Hydrogen Autotransfer Reactions.

    PubMed

    Obora, Yasushi

    2016-04-01

    The development of practical, efficient, and atom-economical methods for the formation of carbon-carbon bonds remains a topic of considerable interest in current synthetic organic chemistry. In this review, we have summarized selected topics from the recent literature with particular emphasis on C-alkylation processes involving hydrogen transfer using alcohols as alkylation reagents. This review includes selected highlights concerning recent progress towards the modification of catalytic systems for the α-alkylation of ketones, nitriles, and esters. Furthermore, we have devoted a significant portion of this review to the methylation of ketones, alcohols, and indoles using methanol. Lastly, we have also documented recent advances in β-alkylation methods involving the dimerization of alcohols (Guerbet reaction), as well as new developments in C-alkylation methods based on sp (3) C-H activation. PMID:27573136

  3. Theory Of Alkyl Terminated Silicon Quantum Dots

    SciTech Connect

    Reboredo, F; Galli, G

    2004-08-19

    We have carried out a series of ab-initio calculations to investigate changes in the optical properties of Si quantum dots as a function of surface passivation. In particular, we have compared hydrogen passivated dots with those having alkyl groups at the surface. We find that, while on clusters with reconstructed surfaces a complete alkyl passivation is possible, steric repulsion prevents full passivation of Si dots with unreconstructed surfaces. In addition, our calculations show that steric repulsion may have a dominant effect in determining the surface structure, and eventually the stability of alkyl passivated clusters, with results dependent on the length of the carbon chain. Alkyl passivation weakly affects optical gaps of silicon quantum dots, while it substantially decreases ionization potentials and electron affinities and affect their excited state properties. On the basis of our results we propose that alkyl terminated quantum dots may be size selected taking advantage of the change in ionization potential as a function of the cluster size.

  4. 2-Aryl-2-nitroacetates as Central Precursors to Aryl Nitromethanes, α-Ketoesters, and α-Amino Acids

    PubMed Central

    Metz, Alison E.

    2013-01-01

    Nitroarylacetates are useful small molecular building blocks that act as precursors to α-ketoesters and aryl nitromethanes as well as α-amino acids. Methods were developed that produce each of these compound types in good yields. Two different conditions for decarboxylation are discussed for substrates with neutral and electron-poor aryl groups versus electron-rich aryl groups. For formation of the α-ketoesters, new mild conditions for the Nef disproportionation were identified. PMID:23245626

  5. Metal-Free Mediated Meerwein-Type Reaction: A Radical Cascade Arylation/Aryl Migration/Desulfonylation of Conjugated Alkenes.

    PubMed

    Ni, Zhangqin; Huang, Xin; Pan, Yuanjiang

    2016-06-01

    A metal-free cascade arylation/aryl migration/desulfonylation of N-phenyl-N-(phenylsulfonyl)methacrylamide is described. The in situ generated diazonium salts from anilines and t-BuONO are used as aryl precursors. This process provides an efficient strategy for the synthesis of α-all-carbon quaternary stereocenters amides. A radical mechanism was proposed for this transformation. PMID:27219900

  6. Palladium-Catalyzed Benzylic Arylation of Pyridylmethyl Silyl Ethers: One-Pot Synthesis of Aryl(pyridyl)methanols.

    PubMed

    Rivero, Alexandra R; Kim, Byeong-Seon; Walsh, Patrick J

    2016-04-01

    An efficient palladium-catalyzed direct arylation of pyridylmethyl silyl ethers with aryl bromides is described. A Pd(OAc)2/NIXANTPHOS-based catalyst provides aryl(pyridyl)methyl alcohol derivatives in good to excellent yields (33 examples, 57-100% yield). This protocol is compatible with different silyl ether protecting groups, affording either the protected or the free alcohols in an effective one-pot process. The scalability of the reaction is demonstrated. PMID:27004592

  7. Highly branched sulfonated poly(fluorenyl ether ketone sulfone)s membrane for energy efficient vanadium redox flow battery

    NASA Astrophysics Data System (ADS)

    Yin, Bibo; Li, Zhaohua; Dai, Wenjing; Wang, Lei; Yu, Lihong; Xi, Jingyu

    2015-07-01

    A series of highly branched sulfonated poly (fluorenyl ether ketone sulfone)s (HSPAEK) are synthesized by direct polycondensation reactions. The HSPAEK with 8% degree of branching is further investigated as membrane for vanadium redox flow battery (VRFB). The HSPAEK membrane prepared by solution casting method exhibits smooth, dense and tough morphology. It possesses very low VO2+ permeability and high ion selectivity compared to those of Nafion 117 membrane. When applied to VRFB, this novel membrane shows higher coulombic efficiency (CE, 99%) and energy efficiency (EE, 84%) than Nafion 117 membrane (CE, 92% and EE, 78%) at current density of 80 mA cm-2. Besides, the HSPAEK membrane shows super stable CE and EE as well as excellent discharge capacity retention (83%) during 100 cycles life test. After being soaked in 1.5 mol L-1 VO2+ solution for 21 days, the weight loss of HSPAEK membrane and the amount of VO2+ reduced from VO2+ are only 0.26% and 0.7%, respectively, indicating the superior chemical stability of the membrane.

  8. α-Sulfonyl succinimides: versatile sulfinate donors in Fe-catalyzed, salt-free, neutral allylic substitution.

    PubMed

    Jegelka, Markus; Plietker, Bernd

    2011-09-01

    Allyl sulfones are versatile intermediates in organic chemistry. The presence of two distinct functional groups sets the stage for a plethora of subsequent transformations. However, despite these advantages the preparation of regioisomerically enriched sulfones is not easy. The use of sulfinate salts as nucleophiles in substitutions is frequently accompanied by side reactions such as π-bond migration, β-elimination, and so on. Herein we present a preparatively simple way to synthesize a variety of different aryl or alkyl allyl sulfones starting from readily accessible allylic carbonates. By employing aryl or alkyl α-sulfonyl succinimides as sulfinate synthons, mild and regioselective ipso substitution of diverse allylic carbonates was realized. PMID:21818793

  9. Palladium-catalyzed cross-coupling reactions of aryl boronic acids with aryl halides in water.

    PubMed

    Wang, Shaoyan; Zhang, Zhiqiang; Hu, Zhizhi; Wang, Yue; Lei, Peng; Chi, Haijun

    2009-01-01

    An efficient Suzuki cross-coupling reaction using a variety of aryl halides in neat water was developed. The Pd-catalyzed reaction between aryl bromides or chlorides and phenyl boronic acids was compatible with various functional groups and affords biphenyls in good to excellent yields without requirement of organic cosolvents. The air stability and solubility in water of the palladium-phosphinous acid complexes were considered to facilitate operation of the coupling reaction and product isolation. The reaction conditions including Pd catalyst selection, temperature, base and catalyst recoverability were also investigated. PMID:25084408

  10. Ionic liquids composed of phosphonium cations and organophosphate, carboxylate, and sulfonate as lubricant antiwear additives

    DOE PAGESBeta

    Zhou, Yan; Dyck, Jeffrey; Graham, Todd; Luo, Huimin; Leonard, Donovan N.; Qu, Jun

    2014-10-20

    Oil-soluble phosphonium-based ionic liquids (ILs) have recently been reported as potential ashless lubricant additives. This study is to expand the IL chemistry envelope and to achieve fundamental correlations between the ion structures and ILs’ physiochemical and tribological properties. Here we present eight ILs containing two different phosphonium cations and seven different anions from three groups: organophosphate, carboxylate, and sulfonate. The oil solubility of ILs seems largely governed by the IL molecule size and structure complexity. When used as oil additives, the ranking of effectiveness in wear protection for the anions are: organophosphate > carboxylate > sulfonate. All selected ILs outperformedmore » a commercial ashless anti-wear additive. Surface characterization from the top and the cross-section revealed the nanostructures and compositions of the tribo-films formed by the ILs. Some fundamental insights were achieved: branched and long alkyls improve the IL’s oil solubility, anions of a phosphonium-phosphate IL contribute most phosphorus in the tribofilm, and carboxylate anions, though free of P, S, N, or halogen, can promote the formation of an anti-wear tribofilm.« less

  11. Ionic liquids composed of phosphonium cations and organophosphate, carboxylate, and sulfonate as lubricant antiwear additives

    SciTech Connect

    Zhou, Yan; Dyck, Jeffrey; Graham, Todd; Luo, Huimin; Leonard, Donovan N.; Qu, Jun

    2014-10-20

    Oil-soluble phosphonium-based ionic liquids (ILs) have recently been reported as potential ashless lubricant additives. This study is to expand the IL chemistry envelope and to achieve fundamental correlations between the ion structures and ILs’ physiochemical and tribological properties. Here we present eight ILs containing two different phosphonium cations and seven different anions from three groups: organophosphate, carboxylate, and sulfonate. The oil solubility of ILs seems largely governed by the IL molecule size and structure complexity. When used as oil additives, the ranking of effectiveness in wear protection for the anions are: organophosphate > carboxylate > sulfonate. All selected ILs outperformed a commercial ashless anti-wear additive. Surface characterization from the top and the cross-section revealed the nanostructures and compositions of the tribo-films formed by the ILs. Some fundamental insights were achieved: branched and long alkyls improve the IL’s oil solubility, anions of a phosphonium-phosphate IL contribute most phosphorus in the tribofilm, and carboxylate anions, though free of P, S, N, or halogen, can promote the formation of an anti-wear tribofilm.

  12. C-8 Modifications of 3-alkyl-1,8-dibenzylxanthines as Inhibitors of Human Cytosolic Phosphoenolpyruvate Carboxykinase

    SciTech Connect

    Pietranico,S.; Foley, L.; Huby, N.; Yun, W.; Dunten, P.; Vermeulen, J.; Wang, P.; Toth, K.; Ramsey, G.; et al.

    2007-01-01

    New modifications on the C-8 4-aminobenzyl unit of the previously reported 3-alkyl-1,8-dibenzylxanthine inhibitors of cPEPCK are presented. The most active compound reported here is the 5-chloro-1,3-dimethyl-1H-pyrazole-4-sulfonic acid amide derivative 2 with an IC{sub 50} of 0.29 {+-} 0.08 {mu}M. An X-ray analysis of a heteroaromatic sulfonamide is presented showing a new {pi}-{pi} interaction.

  13. Evidence for In Situ Catalyst Modification During the Pd-Catalyzed Conversion of Aryl Triflates to Aryl Fluorides

    PubMed Central

    Maimone, Thomas J.; Milner, Phillip J.; Kinzel, Tom; Zhang, Yong; Takase, Michael K.; Buchwald, Stephen L.

    2012-01-01

    A mechanistic investigation of the Pd-catalyzed conversion of aryl triflates to fluorides is presented. Studies reveal that C—F reductive elimination from an LPd(II)(aryl) fluoride complex (L = t-BuBrettPhos (2), RockPhos (3)) does not occur when the aryl group is electron rich. Evidence is presented that a modified phosphine, generated in-situ, serves as the actual supporting ligand during catalysis with such substrates. A preliminary study of the reactivity of an LPd(II)(aryl) fluoride complex based on this modified ligand is reported. PMID:21999801

  14. Evidence for in situ catalyst modification during the Pd-catalyzed conversion of aryl triflates to aryl fluorides.

    PubMed

    Maimone, Thomas J; Milner, Phillip J; Kinzel, Tom; Zhang, Yong; Takase, Michael K; Buchwald, Stephen L

    2011-11-16

    A mechanistic investigation of the Pd-catalyzed conversion of aryl triflates to fluorides is presented. Studies reveal that C-F reductive elimination from a LPd(II)(aryl)F complex (L = t-BuBrettPhos or RockPhos) does not occur when the aryl group is electron rich. Evidence is presented that a modified phosphine, generated in situ, serves as the actual supporting ligand during catalysis with such substrates. A preliminary study of the reactivity of a LPd(II)(aryl)F complex based on this modified ligand is reported. PMID:21999801

  15. Mass spectrometry of analytical derivatives. 1. Cyanide cations in the spectra of N- alkyl-N-perfluoroacyl- α-amino acids and their methyl esters.

    PubMed

    Todua, Nino G; Tretyakov, Kirill V; Mikaia, Anzor I

    2015-01-01

    The central mission for the development of the National Institute of Standards and Technology/National Institutes of Health/Environmental Protection Agency Mass Spectral Library is the acquisition of reference gas chromatography-mass spectrometry data for important compounds and their chemical modification products. The addition of reliable reference data of various derivatives of amino acids to The Library, and the study of their behavior under electron ionization conditions may be useful for their identification, structure elucidation and a better understanding of the data obtained when the same derivatives are subjected to other ionization methods. N-Alkyl-N-perfluoroacyl derivatives of amino acids readily produce previously unreported alkylnitrilium cations of composition [HC≡N-alkyl](+). Homologous [HC≡N-aryl](+) cations are typical for corresponding N-aryl analogs. The formation of other ions characteristic for these derivatives involves oxygen rearrangement giving rise to ions [C(n)F(2n+1)-C≡N(+)C(n)H(2n+1)] and [CnF(2n+1)-C≡N(+)-aryl]. The introduction of an N-benzyl substituent in a molecule favors a process producing benzylidene iminium cations. L-Threonine and L-cysteine derivatives exhibit more fragmentation pathways not typical for other α-amino acids; additionally, the N(ω)- amino group in L-lysine directs the dissociation process and provides structural information on the substitution at the amino functions in the molecule. PMID:26307698

  16. Sorption of sodium dodecylbenzene sulfonate by montmorillonite.

    PubMed

    Yang, Kun; Zhu, Lizhong; Xing, Baoshan

    2007-01-01

    Sorption of linear alkylbenzene sulfonates by soils and sediments is an important process that may affect their fate, transport, toxicity and their application in remediation of contaminated soil and groundwater. In this study, batch experiments were conducted to elucidate the sorption of a widely used anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), by montmorillonite. It was observed that: (i) SDBS was sorbed significantly by montmorillonite saturated with Ca(2+), but little by Na-saturated montmorillonite; (ii) the amount of SDBS sorbed by Ca(2+)-montmorillonite was enhanced by NaCl; and (iii) no significant intercalation of SDBS into Ca(2+)-montmorillonite was observed by X-ray diffraction (XRD) analysis. These results indicate that the removal of SDBS by Ca(2+)-montmorillonite was primarily attributed to the precipitation between DBS(-) and Ca(2+) in solution which was released from montmorillonite via cation exchange. These results will help us to understand the sorption behavior and environmental effects of anionic surfactants. PMID:16759775

  17. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1993-01-05

    Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70 C and 500 C and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

  18. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1993-09-07

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 figures.

  19. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1994-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  20. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1994-06-14

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  1. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.

    1989-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  2. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1993-01-01

    Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70.degree. C. and 500.degree. C. and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

  3. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1993-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  4. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.

    1989-07-18

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  5. Synthesis and antioxidant activity of some 1-aryl/aralkyl piperazine derivatives with xanthine moiety at N4

    PubMed Central

    Andonova, Lily; Zheleva-Dimitrova, Dimitrina; Georgieva, Maya; Zlatkov, Alexander

    2014-01-01

    Piperazine nucleus is one of the most important heterocyclic systems exhibiting remarkable pharmacological activities. Thus, in the current study six new aryl/aralkyl substituted piperazine derivatives, containing methylxanthine moiety were synthesized and their structures were confirmed by IR and 1H NMR analysis. All compounds were in vitro screened for their activity as antioxidants using DPPH (2,2′-Diphenyl-1-picrylhydrazyl), ABTS (2,2′-azinobis-(3-ethylbenzo thiazine-6-sulfonic acid)) and FRAP (ferric reducing/antioxidant power) methods. The antioxidant activity of the studied compounds against lipid peroxidation was also measured. The highest antioxidant activity was demonstrated by compound 3c. It is obvious that the presence of a hydroxyl group in the structure is essential for the antioxidant properties and should be taken into consideration in further design of structures with potential antioxidant properties. PMID:26019603

  6. α-Allyl-α-aryl α-Amino Esters in the Asymmetric Synthesis of Acyclic and Cyclic Amino Acid Derivatives by Alkene Metathesis

    PubMed Central

    2015-01-01

    Allylating agents were explored for the asymmetric synthesis of α-allyl-α-aryl α-amino acids by tandem N-alkylation/π-allylation. Cross-metathesis of the tandem product was developed to provide allylic diversity not afforded in the parent reaction; the synthesis of homotyrosine and homoglutamate analogues was completed. Cyclic α-amino acid derivatives could be accessed by ring-closing metathesis presenting a viable strategy to higher ring homologue of enantioenriched α-substituted proline. The eight-membered proline analogue was successfully converted to the pyrrolizidine natural product backbone. PMID:24828423

  7. Mechanism-based inactivation of benzo(a)pyrene hydroxylase by aryl acetylenes and aryl olefins

    SciTech Connect

    Gan, L.S.; Lu, J.Y.L.; Alworth, W.L.

    1986-05-01

    A series of aryl acetylenes and aryl olefins have been examined as substrates and inhibitors of cytochrome P-450 dependent monooxgenases in liver microsomes from 5,6-benzoflavone or phenobarbital pretreated rats. 1-Ethynylpyrene, 3-ethynylperylene, 2-ethynylfluorene, methyl 1-pyrenyl acetylene, cis- and trans-1-(2-bromovinyl)pyrene, and 1-allylpyrene serve as mechanism-based irreversible inactivators (suicide inhibitors) of benzo(a)pyrene hydroxylase, while 1-vinylpyrene and phenyl 1-pyrenyl acetylene do not cause a detectable suicide inhibition of benzo(a)pyrene hydroxylase. The mechanism-based loss of benzo(a)pyrene hydroxylase caused by the aryl acetylenes is not accompanied by a corresponding loss of the P-450 content of the microsomes (suicide destruction). The suicide inhibition by these aryl acetylenes therefore does not involve covalent binding to the heme moiety of the monooxygenase. Nevertheless, in the presence of NADPH, /sup 3/H-labeled 1-ethynylpyrene becomes covalently attached to the cytochrome P-450 protein; the measured stoichiometry of binding is one 1-ethynylpyrene per P-450 heme unit. The authors conclude that the inhibition of benzo(a)pyrene hydroxylase produced by 1-ethynylpyrene may be related to the mechanism of suicide inhibition of P-450 activity by chloramphenicol rather than the mechanism of suicide destruction of P-450 previously described for acetylene and propyne.

  8. Nickel catalyzed α-arylation of ketones with aryltrimethylammonium triflates.

    PubMed

    Li, Jing; Wang, Zhong-Xia

    2016-08-21

    Nickel-catalyzed α-arylation of ketones involving aromatic C-N cleavage has been accomplished. Intermolecular coupling of aromatic ketones with a variety of aryltrimethylammonium triflates was achieved in the presence of Ni(COD)2, IPr·HCl, and LiOBu(t), giving α-arylated ketones in reasonable to excellent yields. PMID:27443786

  9. Novel Haloperoxidase from the Agaric Basidiomycete Agrocybe aegerita Oxidizes Aryl Alcohols and Aldehydes

    PubMed Central

    Ullrich, René; Nüske, Jörg; Scheibner, Katrin; Spantzel, Jörg; Hofrichter, Martin

    2004-01-01

    Agrocybe aegerita, a bark mulch- and wood-colonizing basidiomycete, was found to produce a peroxidase (AaP) that oxidizes aryl alcohols, such as veratryl and benzyl alcohols, into the corresponding aldehydes and then into benzoic acids. The enzyme also catalyzed the oxidation of typical peroxidase substrates, such as 2,6-dimethoxyphenol (DMP) or 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS). A. aegerita peroxidase production depended on the concentration of organic nitrogen in the medium, and highest enzyme levels were detected in the presence of soybean meal. Two fractions of the enzyme, AaP I and AaP II, which had identical molecular masses (46 kDa) and isoelectric points of 4.6 to 5.4 and 4.9 to 5.6, respectively (corresponding to six different isoforms), were identified after several steps of purification, including anion- and cation-exchange chromatography. The optimum pH for the oxidation of aryl alcohols was found to be around 7, and the enzyme required relatively high concentrations of H2O2 (2 mM) for optimum activity. The apparent Km values for ABTS, DMP, benzyl alcohol, veratryl alcohol, and H2O2 were 37, 298, 1,001, 2,367 and 1,313 μM, respectively. The N-terminal amino acid sequences of the main AaP II spots blotted after two-dimensional gel electrophoresis were almost identical and exhibited almost no homology to the sequences of other peroxidases from basidiomycetes, but they shared the first three amino acids, as well as two additional amino acids, with the heme chloroperoxidase (CPO) from the ascomycete Caldariomyces fumago. This finding is consistent with the fact that AaP halogenates monochlorodimedone, the specific substrate of CPO. The existence of haloperoxidases in basidiomycetous fungi may be of general significance for the natural formation of chlorinated organic compounds in forest soils. PMID:15294788

  10. Synthesis, molecular structure and spectroscopic studies of some new quinazolin-4(3H)-one derivatives; an account on the N- versus S-Alkylation

    NASA Astrophysics Data System (ADS)

    Hagar, Mohamed; Soliman, Saied M.; Ibid, Farahate; El Ashry, El Sayed H.

    2016-03-01

    A new series of N- and S-alkylated products of 3-aryl-1H,3H-quinazolin-2,4-dione and 3-aryl-2-mercapto-3H-quinazolin-4-one, respectively, were prepared in good yields via efficient nucleophilic substitution reaction of the SH and NH substrates with methyl iodide, ethyl bromoacetate, allyl bromide, propagyl bromide, 2-bromoethanol, 1,3-dibromopropane or phenacyl bromide in DMF as a solvent and anhydrous potassium carbonate. The quinazolin-2,4-dione favored the N-alkylation while the 2-mercapto-3H-quinazolin-4-one goes via the S-alkylation. DFT reactivity studies showed that the former have the N-site with higher nucleophilicity compared to the O-site. In contrast, the S-site is the more nucleophilic centre than the N-atom of the latter. The structures of the synthesized products have been established on the basis of their melting point (m.p), IR and 1HNMR data. The molecular structures of the products were calculated using the DFT B3LYP/6-311G(d,p) method. The electronic and spectroscopic properties (Uv-Vis and NMR spectra) were calculated using the same level of theory. The chemical reactivity descriptors that could help to understand the biological activity of the products are also predicted.

  11. Aryl Hydrocarbon Receptor and Lung Cancer

    PubMed Central

    Tsay, Junchieh J.; Tchou-Wong, Kam-Meng; Greenberg, Alissa K.; Pass, Harvey; Rom, William N.

    2013-01-01

    The leading cause of lung cancer is exposure to cigarette smoke and other environmental pollutants, which include formaldehyde, acrolein, benzene, dioxin, and polycyclic aromatic hydrocarbons (PAHs). PAHs and dioxins are exogenous ligands that directly bind to the aryl hydrocarbon receptor (AhR), a transcription factor that activates xenobiotic metabolism, histone modification (an important step in DNA methylation), and, ultimately, tumorigenesis. Here we summarize the current understanding of AhR and its role in the development of lung cancer, including its influence on cell proliferation, angiogenesis, inflammation, and apoptosis. PMID:23564762

  12. A mechanistic study explaining the synergistic viscosity increase obtained from polyethylene oxide (PEO) and {beta}-naphthalene sulfonate (BNS) in shotcrete

    SciTech Connect

    Pickelmann, J.; Plank, J.

    2012-11-15

    In shotcrete, a combination of polyethylene oxide (PEO) and {beta}-naphthalene sulfonate (BNS) is commonly applied to reduce rebound. Here, the mechanism for the synergistic viscosity increase resulting from this admixture combination was investigated via x-ray diffraction (XRD), infrared and nuclear magnetic resonance (NMR) spectroscopy. It was found that the electron-rich aromatic rings present in BNS donate electrons to the alkyl protons of PEO and thus increase the electron density there. This rare interaction is known as CH-{pi} interaction and leads to the formation of a supramolecular structure whereby PEO chains bind weakly to BNS molecules. Through this mechanism a polymer network exhibiting exceptionally high molecular weight and thus viscosity is formed. Among polycondensates, sulfanilic acid-phenol-formaldehyde (SPF) provides even higher synergy with PEO than BNS while melamine (PMS), acetone (AFS) or polycarboxylate (PCE) based superplasticizers do not work at all. Effectiveness of lignosulfonates is dependent on their degree of sulfonation.

  13. Palladium-Catalyzed Ortho-Arylation of Carbamate-Protected Estrogens.

    PubMed

    Bedford, Robin B; Brenner, Peter B; Durrant, Steven J; Gallagher, Timothy; Méndez-Gálvez, Carolina; Montgomery, Michelle

    2016-05-01

    The palladium-catalyzed ortho-arylation of diethyl carbamate-protected estrone and estriol with aryl iodides gives the 2-arylated analogues. Subsequent removal of the carbamate directing group furnishes 2-arylated estrone, estradiol, or estriol depending on the method used. PMID:27057762

  14. Sulfonimide-containing poly(arylene ether)s and poly(arylene ether sulfone)s, methods for producing the same, and uses thereof

    DOEpatents

    Hofmann, Michael A.

    2006-11-14

    The present invention is directed to sulfonimide-containing polymers, specifically sulfonimide-containing poly(arylene ether)s and sulfonimide-containing poly(arylene ether sulfone)s, and processes for making the sulfonimide-containing poly(arylene ether)s and sulfonimide-containing poly(arylene ether sulfone)s, for use conductive membranes and fuel cells.

  15. Motor fuel alkylation process utilizing low acid

    SciTech Connect

    Kocal, J.A.; Imai, T.

    1987-01-06

    A process is described for the alkylation of an isoparaffin with an olefin acting agent comprising contacting the isoparaffin with the olefin acting agent at alkylation conditions in the presence of a catalyst. The catalyst consists essentially of an anhydrous, nonalcoholic mixture of from about 5 to 15 wt. % methyl tert-butyl ether and from 85 to 95 wt. % hydrofluoric acid. The volumetric ratio of hydrofluoric acid to isoparaffin and olefin acting agent is less than 0.75.

  16. Thermally induced alkylation of diamond.

    PubMed

    Hoeb, Marco; Auernhammer, Marianne; Schoell, Sebastian J; Brandt, Martin S; Garrido, Jose A; Stutzmann, Martin; Sharp, Ian D

    2010-12-21

    We present an approach for the thermally activated formation of alkene-derived self-assembled monolayers on oxygen-terminated single and polycrystalline diamond surfaces. Chemical modification of the oxygen and hydrogen plasma-treated samples was achieved by heating in 1-octadecene. The resulting layers were characterized using X-ray photoelectron spectroscopy, thermal desorption spectroscopy, atomic force microscopy, Fourier transform infrared spectroscopy, and water contact angle measurements. This investigation reveals that alkenes selectively attach to the oxygen-terminated sites via covalent C-O-C bonds. The hydrophilic oxygen-terminated diamond is rendered strongly hydrophobic following this reaction. The nature of the process limits the organic layer growth to a single monolayer, and FTIR measurements reveal that such monolayers are dense and well ordered. In contrast, hydrogen-terminated diamond sites remain unaffected by this process. This method is thus complementary to the UV-initiated reaction of alkenes with diamond, which exhibits the opposite reactivity contrast. Thermal alkylation increases the range of available diamond functionalization strategies and provides a means of straightforwardly forming single organic layers in order to engineer the surface properties of diamond. PMID:21090790

  17. N-Alkylation by Hydrogen Autotransfer Reactions.

    PubMed

    Ma, Xiantao; Su, Chenliang; Xu, Qing

    2016-06-01

    Owing to the importance of amine/amide derivatives in all fields of chemistry, and also the green and environmentally benign features of using alcohols as alkylating reagents, the relatively high atom economic dehydrative N-alkylation reactions of amines/amides with alcohols through hydrogen autotransfer processes have received much attention and have developed rapidly in recent decades. Various efficient homogeneous and heterogeneous transition metal catalysts, nano materials, electrochemical methods, biomimetic methods, asymmetric N-alkylation reactions, aerobic oxidative methods, and even certain transition metal-free, catalyst-free, or autocatalyzed methods, have also been developed in recent years. With a brief introduction to the background and developments in this area of research, this chapter focuses mainly on recent progress and technical and conceptual advances contributing to the development of this research in the last decade. In addition to mainstream research on homogeneous and heterogeneous transition metal-catalyzed reactions, possible mechanistic routes for hydrogen transfer and alcohol activation, which are key processes in N-alkylation reactions but seldom discussed in the past, the recent reports on computational mechanistic studies of the N-alkylation reactions, and the newly emerged N-alkylation methods based on novel alcohol activation protocols such as air-promoted reactions and transition metal-free methods, are also reviewed in this chapter. Problems and bottlenecks that remained to be solved in the field, and promising new research that deserves greater future attention and effort, are also reviewed and discussed. PMID:27573267

  18. Boiling significantly promotes photodegradation of perfluorooctane sulfonate.

    PubMed

    Lyu, Xian-Jin; Li, Wen-Wei; Lam, Paul K S; Yu, Han-Qing

    2015-11-01

    The application of photochemical processes for perfluorooctane sulfonate (PFOS) degradation has been limited by a low treatment efficiency. This study reports a significant acceleration of PFOS photodegradation under boiling condition compared with the non-boiling control. The PFOS decomposition rate increased with the increasing boiling intensity, but declined at a higher hydronium level or under oxygenation. These results suggest that the boiling state of solution resulted in higher effective concentrations of reactants at the gas-liquid interface and enhanced the interfacial mass transfer, thereby accelerating the PFOS decomposition. This study broadens our knowledge of PFOS photodegradation process and may have implications for development of efficient photodegradation technologies. PMID:26117498

  19. Titania-Promoted Carboxylic Acid Alkylations of Alkenes and Cascade Addition–Cyclizations

    PubMed Central

    2014-01-01

    Photochemical reactions employing TiO2 and carboxylic acids under dry anaerobic conditions led to several types of C–C bond-forming processes with electron-deficient alkenes. The efficiency of alkylation varied appreciably with substituents in the carboxylic acids. The reactions of aryloxyacetic acids with maleimides resulted in a cascade process in which a pyrrolochromene derivative accompanied the alkylated succinimide. The selectivity for one or other of these products could be tuned to some extent by employing the photoredox catalyst under different conditions. Aryloxyacetic acids adapted for intramolecular ring closures by inclusion of 2-alkenyl, 2-aryl, or 2-oximinyl functionality reacted rather poorly. Profiles of reactant consumption and product formation for these systems were obtained by an in situ NMR monitoring technique. An array of different catalyst forms were tested for efficiency and ease of use. The proposed mechanism, involving hole capture at the TiO2 surface by the carboxylates followed by CO2 loss, was supported by EPR spectroscopic evidence of the intermediates. Deuterium labeling indicated that the titania likely donates protons from surface hydroxyl groups as well as supplying electrons and holes, thus acting as both a catalyst and a reaction partner. PMID:24437519

  20. Practical Direct α-Arylation of Cyclopentanones by Palladium/Enamine Cooperative Catalysis.

    PubMed

    Xu, Yan; Su, Tianshun; Huang, Zhongxing; Dong, Guangbin

    2016-02-12

    Direct arylation of cyclopentanones has been a long-standing challenge because of competitive self-aldol condensation and multiple arylations. Reported herein is a direct mono-α-C-H arylation of cyclopentanones with aryl bromides which is enabled by palladium/amine cooperative catalysis. This method is scalable and chemoselective with broad functional-group tolerance. Application to controlled sequential arylation of cyclopentanones has been also demonstrated. PMID:26840218

  1. 40 CFR 721.1625 - Alkylbenzene sulfonate, amine salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylbenzene sulfonate, amine salt... Substances § 721.1625 Alkylbenzene sulfonate, amine salt. (a) Chemical substance and significant new uses... salt (PMN P-90-456) is subject to reporting under this section for the significant new use described...

  2. 40 CFR 721.1625 - Alkylbenzene sulfonate, amine salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkylbenzene sulfonate, amine salt... Substances § 721.1625 Alkylbenzene sulfonate, amine salt. (a) Chemical substance and significant new uses... salt (PMN P-90-456) is subject to reporting under this section for the significant new use described...

  3. Sulfonated Nanoplates in Proton Conducting Membranes for Fuel Cells

    SciTech Connect

    Chen, W.F.; Ni’mah, H.; Yu-Cheng Shen, Y.-C.; Kuo, P.-L.

    2011-09-29

    Surface-functionalized nanoplates are synthesized by anchoring sulfonic acid containing siloxanes on zirconium phosphate, and in turn blended with Nafion to fabricate proton conducting membranes. The effects of these sulfonated nanoplates on proton conduction, hydro-characteristics and fuel cell performance are reported.

  4. Synthesis of basic and overbasic sulfonate detergent additives

    SciTech Connect

    Abou El Naga, H.H.; Abd El-Azim, W.M.; Bendary, S.A.; Awad, N.G.

    1993-12-01

    Heavy alkylbenzene, which accumulates as a by-product from linear alkylbenzene synthesis, is evaluated as a starting material for preparation of basic and over basic sulfonate detergent additives. Chemical structure analysis showed that this by-product contains several components in different proportions. Most of these components, as traced via mass spectrometry, showed the presence of paraffinic side chains within the carbon range C{sub 11}--C{sub 22}. Accordingly, sulfonation conditions for it were adjusted to optimize the reaction yield and sulfonic quality. Neutralization of the sulfonic acid was carried out by adding CaO in the presence of methanol as a promoter. Preparation of over basic sulfonate was run via a carbonation process at 55--60 C. Evaluations of synthesized basic calcium sulfonate in comparison to a commercial additive is supported by its efficiency as a detergent additive. The synthesized product has a higher total base number and Ca content than those for the commercial one. On the other hand, evaluation of the synthesized overbasic calcium sulfonate compared with overbasic commercial additives with medium and high alkalinity indicated that the synthesized product can be classified as overbasic calcium sulfonate with medium alkalinity, good dispersive power, and detergent efficiency.

  5. 40 CFR 721.1625 - Alkylbenzene sulfonate, amine salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkylbenzene sulfonate, amine salt... Substances § 721.1625 Alkylbenzene sulfonate, amine salt. (a) Chemical substance and significant new uses... salt (PMN P-90-456) is subject to reporting under this section for the significant new use described...

  6. 40 CFR 721.1625 - Alkylbenzene sulfonate, amine salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkylbenzene sulfonate, amine salt... Substances § 721.1625 Alkylbenzene sulfonate, amine salt. (a) Chemical substance and significant new uses... salt (PMN P-90-456) is subject to reporting under this section for the significant new use described...

  7. Synthesis of cyclic sulfones by ring-closing metathesis.

    PubMed

    Yao, Qingwei

    2002-02-01

    A general and highly efficient synthesis of cyclic sulfones based on ring-closing metathesis has been developed. The synthetic utility of the resulting cyclic sulfones was demonstrated by their participation in stereoselective Diels-Alder reactions and transformation to cyclic dienes by the Ramberg-Bäcklund reaction. PMID:11820896

  8. MATERNAL AND DEVELOPMENTAL TOXICITY OF PERFLUOROOCTANE SULFONATE IN THE RAT

    EPA Science Inventory

    MATERNAL AND DEVELOPMENTAL TOXICITY OF PERFLUOROOCTANE SULFONATE IN THE RAT.
    C. Lau and J.M. Rogers, Reproductive Toxicology Division, NHEERL, ORD, USEPA, Research Triangle Park, NC, USA

    Perfluorooctane sulfonate (PFOS), an environmentally persistent compound used ...

  9. N-Oxide as an Intramolecular Oxidant in the Baeyer-Villiger Oxidation: Synthesis of 2-Alkyl-2H-indazol-3-yl Benzoates and 2-Alkyl-1,2-dihydro-3H-indazol-3-ones.

    PubMed

    Schütznerová, Eva; Krchňák, Viktor

    2016-05-01

    In this study, we describe the intramolecular Baeyer-Villiger oxidation of ketones to esters using N-oxide. 2-Nitro-N-alkyl-N-(2-oxo-2-phenylethyl)benzenesulfonamide compounds are known to undergo base-mediated C-arylation followed by N-N bond formation, producing unstable five-membered ring intermediates that spontaneously dehydrate to indazole oxides. We identified the reaction conditions under which the cyclic intermediate undergoes acid-mediated intramolecular Baeyer-Villiger oxidation of the ketone in which N-oxide serves as the intramolecular oxidizing agent. The solid-phase synthesis plays a critical role in the successful transformation, allowing rapid access to the unstable but Baeyer-Villiger oxidation-prone intermediate. This synthetic route provides practical access to 2-alkyl-2H-indazol-3-yl benzoates and 2-alkyl-1,2-dihydro-3H-indazol-3-ones, which are known privileged structures possessing remarkable diverse pharmacologically relevant activities. PMID:27035416

  10. Development of a Method for the N-Arylation of Amino Acid Esters with Aryl Triflates.

    PubMed

    King, Sandra M; Buchwald, Stephen L

    2016-08-19

    A general method for the N-arylation of amino acid esters with aryl triflates is described. Both α- and β-amino acid esters, including methyl, tert-butyl, and benzyl esters, are viable substrates. Reaction optimization was carried out by design of experiment (DOE) analysis using JMP software. The mild reaction conditions, which use t-BuBrettPhos Pd G3 or G4 precatalyst, result in minimal racemization of the amino acid ester. This method is the first synthetic application of the t-BuBrettPhos Pd G4 precatalyst. Mechanistic studies show that the observed erosion in enantiomeric excess is due to racemization of the amino acid ester starting material and not of the product. PMID:27498618

  11. From ketones to esters by a Cu-catalyzed highly selective C(CO)-C(alkyl) bond cleavage: aerobic oxidation and oxygenation with air.

    PubMed

    Huang, Xiaoqiang; Li, Xinyao; Zou, Miancheng; Song, Song; Tang, Conghui; Yuan, Yizhi; Jiao, Ning

    2014-10-22

    The Cu-catalyzed aerobic oxidative esterification of simple ketones via C-C bond cleavage has been developed. Varieties of common ketones, even inactive aryl long-chain alkyl ketones, are selectively converted into esters. The reaction tolerates a wide range of alcohols, including primary and secondary alcohols, chiral alcohols with retention of the configuration, electron-deficient phenols, as well as various natural alcohols. The usage of inexpensive copper catalyst, broad substrate scope, and neutral and open air conditions make this protocol very practical. (18)O labeling experiments reveal that oxygenation occurs during this transformation. Preliminary mechanism studies indicate that two novel pathways are mainly involved in this process. PMID:25251943

  12. The copper-catalysed Suzuki-Miyaura coupling of alkylboron reagents: disproportionation of anionic (alkyl)(alkoxy)borates to anionic dialkylborates prior to transmetalation.

    PubMed

    Basnet, Prakash; Thapa, Surendra; Dickie, Diane A; Giri, Ramesh

    2016-09-25

    We report the first example of Cu(I)-catalysed coupling of alkylboron reagents with aryl and heteroaryl iodides that affords products in good to excellent yields. Preliminary mechanistic studies with alkylborates indicate that the anionic (alkoxy)(alkyl)borates, generated from alkyllithium and alkoxyboron reagents, undergo disproportionation to anionic dialkylborates and that both anionic alkylborates are active for transmetalation to a Cu(I)-catalyst. Results from a radical clock experiment and the Hammett plot imply that the reaction likely proceeds via a non-radical pathway. PMID:27540605

  13. Alkyl rearrangement processes in organozirconium complexes. Observation of internal alkyl complexes during hydrozirconation

    SciTech Connect

    Chirik, P.J.; Day, M.W.; Labinger, J.A.; Bercaw, J.E.

    1999-11-10

    Isotopically labeled alkyl zirconocene complexes of the form (CpR{sub n}){sub 2}Zr(CH{sub 2}CDR{sub 2}{prime})(X) (CpR{sub n} = alkyl-substituted cyclopentadienyl; R{prime} = H, alkyl group; X = H, D, Me) undergo isomerization of the alkyl ligand as well as exchange with free olefin in solution under ambient conditions. Increasing the substitution on the Cp ring results in slower isomerization reactions, but these steric effects are small. In contrast, changing X has a very large effect on the rate of isomerization. Pure {sigma}-bonding ligands such as methyl and hydride promote rapid isomerization, whereas {pi}-donor ligands inhibit {beta}-H elimination and hence alkyl isomerization. For ({eta}{sup 5}-C{sub 5}H{sub 5}){sub 2}Zr(R)(Cl), internal alkyl complexes have been observed for the first time. The rate of isomerization depends on the length of the alkyl group: longer alkyl chains (heptyl, hexyl) isomerize faster than shorter chains (butyl). The transient intermediate species have been identified by a combination of isotopic labeling and {sup 1}H, {sup 2}H, and {sup 13}C NMR experiments. The solid-state structure of the zirconocene cyclopentyl chloride complex, Cp{sub 2}Zr(cyclo-C{sub 5}H{sub 9})(Cl), has been determined by X-ray diffraction.

  14. Blend of alkyl phenol ethoxylates and alkyl phenol glycoxylates and their use as surfactants

    SciTech Connect

    Grolitzer, M. A.

    1985-11-12

    Nonionic surfactant compositions useful in forming stable emulsions with oil in saline solutions comprising a blend of: at least one alkyl phenol ethoxylate and at least one alkyl phenol glycoxylate. These surfactant compositions may be employed in enhanced oil recovery processes and other applications where good emulsification and high salinity tolerances are required such as textiles, leather, dairy, concrete grinding aids and drilling muds.

  15. Controlling Structure in Sulfonated Block Copolymer Membranes

    NASA Astrophysics Data System (ADS)

    Truong, Phuc; Stein, Gila; Strzalka, Joe

    2015-03-01

    In many ionic block copolymer systems, the strong incompatibility between ionic and non-ionic segments will trap non-equilibrium structures in the film, making it difficult to engineer the optimal domain sizes and transport pathways. The goal of this work is to establish a framework for controlling the solid-state structure of sulfonated pentablock copolymer membranes. They have ABCBA block sequence, where A is poly(t-butyl styrene), B is poly(hydrogenated isoprene), and C is poly(styrene sulfonate). To process into films, the polymer is dissolved in toluene/n-propanol solvent mixtures, where the solvent proportions and the polymer loading were both varied. Solution-state structure was measured with small angle X-ray scattering (SAXS). We detected micelles with radii that depend on the solvent composition and polymer loading. Film structure was measured with grazing-incidence SAXS, which shows (i) domain periodicity is constant throughout film thickness; (ii) domain periodicity depends on solvent composition and polymer loading, and approximately matches the micelle radii in solutions. The solid-state packing is consistent with a hard sphere structure factor. Results suggest that solid-state structure can be tuned by manipulating the solution-state self-assembly.

  16. Anaerobic degradation of linear alkylbenzene sulfonate.

    PubMed

    Mogensen, Anders S; Haagensen, Frank; Ahring, Birgitte K

    2003-04-01

    Linear alkylbenzene sulfonate (LAS) found in wastewater is removed in the wastewater treatment facilities by sorption and aerobic biodegradation. The anaerobic digestion of sewage sludge has not been shown to contribute to the removal. The concentration of LAS based on dry matter typically increases during anaerobic stabilization due to transformation of easily degradable organic matter. Hence, LAS is regarded as resistant to biodegradation under anaerobic conditions. We present data from a lab-scale semi-continuously stirred tank reactor (CSTR) spiked with linear dodecylbenzene sulfonate (C12 LAS), which show that C12 LAS was biodegradable under methanogenic conditions. Sorption of C12 LAS on sewage sludge was described with a Freundlich isotherm. The C12 LAS sorption was determined with different concentrations of total solids (TS). In the semi-continuously stirred tank reactor, 18% of the added C12 LAS was bioavailable and 20% was biotransformed when spiking with 100 mg/L of C12 LAS and a TS concentration of 14.2 mg/L. Enhanced bioavailability of C12 LAS was obtained in an upflow anaerobic sludge blanket (UASB) reactor inoculated with granular sludge and sewage sludge. Biodegradation under thermophilic conditions was 37% with LAS as sole carbon source. Benzaldehyde was produced in the UASB reactor during LAS transformation. PMID:12685701

  17. Biodegradation of fluorinated alkyl substances.

    PubMed

    Frömel, Tobias; Knepper, Thomas P

    2010-01-01

    The incorporation of fluorine into organic molecules entails both positive and adverse effects. Although fluorine imparts positive and unique properties such as water-and oil-repellency and chemical stability, adverse effects often pervade members of this compound class. A striking property of long perfluoroalkyl chains is their very pronounced environmental persistence. The present review is the first one designed to summarize recent accomplishments in the field of biodegradation of fluorine-containing surfactants, their metabolites, and structural analogs. The pronounced scientific and public interest in these chemicals has given impetus to undertake numerous degradation studies to assess the sources and origins of different fluorinated analog chemical known to exist in the environment. It was shown that biodegradation plays an important role in understanding how fluorinated substances reach the environment and, once they do, what their fate is. Today, PFOS and PFOA are ubiquitously detected as environmental contaminants. Their prominence as contaminants is mainly due to their extreme persistence, which is linked to their perfluoroalkyl chain length. It appears that desulfonation of a highly fluorinated surfactants can be achieved if an α-situated H atom, in relation to the sulfonate group, is present, at least under sulfur-limiting conditions. Molecules that are less heavily fluorinated can show very complex metabolic behavior, as is the case for fluorotelomer alcohols. These compounds are degraded via different but simultaneous pathways, which produce different stable metabolites, one of which is the respective perfluoroalkanoate (8:2-FTOH is transformed to PFOA). Preliminary screening tests indicate that fluorinated functional groups, such as the trifluoromethoxy group and the p-(trifluoromethyl)phenoxy group, may be useful implementations in novel, environmentally benign fluorosurfactants. More specifically, trifluoromethoxy groups constitute a substitute

  18. Alkylation of isobutane with light olefins: Yields of alkylates for different olefins

    SciTech Connect

    Albright, L.F.; Kranz, K.E.; Masters, K.R.

    1993-12-01

    For alkylation of isobutane with C{sub 3}-C{sub 5} olefins using sulfuric acid as the catalyst, the yields of alkylates with different olefins are compared as the operating conditions are changed. The results of recent pilot plant experiments with propylene, C{sub 4} olefins, and C{sub 5} olefins permit such comparisons. The yields expressed as weight of alkylate produced per 100 wt of olefin consumed varied from about 201:100 to 220:100. Weight ratios of the isobutane consumed per olefin consumed vary from about 101:100 to 120:100. differences of yield values are explained by the changes in the overall chemistry. The procedure employed to calculate yields with good accuracy is based on the analysis of the alkylate and the amount of conjunct polymers produced. Based on literature data, yields are also reported for alkylations using HF as the catalyst.

  19. Preparation of 1,7- and 3,9-dideazapurines from 2-amino-3-iodo- and 3-amino-4-iodopyridines and activated acetylenes by conjugate addition and copper-catalyzed intramolecular arylation.

    PubMed

    Zhu, Ying; Back, Thomas G

    2014-11-21

    The conjugate addition of N-formyl derivatives of 2-amino-3-iodo- and 3-amino-4-iodopyridines to acetylenes activated by sulfone, ester, or ketone groups, followed by intramolecular arylation, affords variously substituted 1,7- and 3,9-dideazapurines. The method employs DMF-water as the solvent and copper(II) acetate as the catalyst for the cyclization step. Neither added ligands nor the exclusion of oxygen is necessary. The process therefore provides a simple, convenient, and inexpensive route to this biologically interesting class of products. PMID:25333726

  20. Cyclic (Amino)(aryl)carbenes (CAArCs) as Strong σ-Donating and π-Accepting Ligands for Transition Metals.

    PubMed

    Rao, Bin; Tang, Huarong; Zeng, Xiaoming; Liu, Liu; Melaimi, Mohand; Bertrand, Guy

    2015-12-01

    Cyclic (amino)(aryl)carbenes (CAArCs) result from the replacement of the alkyl substituent of cyclic (alkyl)(amino) carbenes (CAACs) by an aryl group. This structural modification leads to enhanced electrophilicity of the carbene center with retention of the high nucleophilicity of CAACs, and therefore CAArCs feature a small singlet-triplet gap. The isoindolium precursors are readily prepared in good yields, and deprotonation at low temperature, in the presence of [RhCl(cod)]2 and [(Me2S)AuCl] lead to air-stable rhodium and gold CAArC-supported complexes, respectively. The rhodium complexes promote the [3+2] cycloaddition of diphenylcyclopropenone with ethyl phenylpropiolate, and induce the addition of 2-vinylpyridine to alkenes by CH activation. The gold complexes allow for the catalytic three-component preparation of 1,2-dihydroquinolines from aniline and phenyl acetylene. These preliminary results illustrate the potential of CAArC ligands in transition-metal catalysis. PMID:26457345

  1. Catalytic hydrogenolysis of an aryl-aryl carbon-carbon bond with a rhodium complex

    SciTech Connect

    Perthuisot, C.; Jones, W.D. )

    1994-04-20

    Recent publications have brought renewed interest to the quest for homogeneous catalytic activation of carbon-carbon bonds. However, except for a few reports of biphenylene cleavage, the mechanism and scope of aryl-aryl C-C bond activation remains relatively uninvestigated. In the hope of overcoming the obstacle of weak M-C bonds, we used a rhodium system that should provide a thermodynamically favored C-C cleaved complex by making strong metal-aryl bonds. Reaction of (C[sub 5]Me[sub 5])Rh(PMe[sub 3])(Ph)(H) (1) with 1.5 equiv of biphenylene in cyclohexane-d[sub 12] at 65[degree]C resulted in the quantitative formation of (CC[sub 5]Me[sub 5])Rh(PMe[sub 3]) (biphenylenyl(H)) (2), along with a small amount of a red complex. The cleavage of the well-hidden carbon-carbon bond of biphenylene described relies both on a strained four-membered ring and on the formation of a stable pentametallacycle. The results show that C-H activation and [eta][sup 2] coordination are probably involved in the process leading to C-C bond cleavage, and valuable information can be obtained from studies of this system. 21 refs., 1 fig.

  2. Aryl hydrocarbon receptor-driven signals inhibit collagen synthesis in the gut.

    PubMed

    Monteleone, Ivan; Zorzi, Francesca; Marafini, Irene; Di Fusco, Davide; Dinallo, Vincenzo; Caruso, Roberta; Izzo, Roberta; Franzè, Eleonora; Colantoni, Alfredo; Pallone, Francesco; Monteleone, Giovanni

    2016-04-01

    Fibrostrictures (FS) are a major complication of Crohn's disease (CD). Pathogenesis of FS is not fully understood, but activation of fibroblasts and excessive collagen deposition are crucial in the development of FS. Here, we investigated the role of aryl hydrocarbon receptor (AhR) in intestinal fibrosis. AhR RNA and protein expression were evaluated in intestinal fibroblasts of CD patients and controls. CD fibroblasts were stimulated with TGF-β1 or TNF-α in the presence or absence of the AhR activator Ficz, an AhR antagonist CH223191, or a specific AhR-silencing RNA. In CD fibroblasts, TGF-β1 and TNF-α increased Col1A1, Col3A1 and α-SMA transcripts and collagen secretion and this effect was reduced by Ficz and upregulated by CH22319. TGF-β1 or TNF-α induced activation of p38 and ERK1/2 MAP kinases was decreased by Ficz and increased by CH223191. The inhibitory effect of Ficz on Map kinase activation and collagen induction was abolished by AhR silencing. To assess the role of AhR in vivo, mice with trinitrobenzene-sulfonic-acid induced colonic fibrosis were given Ficz or CH223191. Mice given either Ficz or CH223191 produced less or more collagen respectively as compared with control mice. Our results indicate that AhR is a negative regulator of profibrotic signals in the gut. PMID:26786786

  3. Aging mechanism of Sulfonated poly(aryl ether ketone) (sPAEK) in an hydroperoxide solution and in fuel cell

    NASA Astrophysics Data System (ADS)

    Perrot, Carine; Gonon, Laurent; Marestin, Catherine; Morin, Arnaud; Gebel, Gérard

    Ex situ and in situ fuel cell degradation of a sPAEK membrane were investigated. Post-mortem analyses of the aged membrane and of the degradation products eluted in water were carried out by NMR, IR, SEC and EDX. Ex situ agings were performed in a low concentration H 2O 2 solution (0.07%) without any metallic catalyst. We exemplify that ex situ accelerated aging tests in such hydrogen peroxide solution are relevant to the chemical degradation in fuel cell. We have shown that a 500 h fuel cell test at moderate temperature (60 °C) induces significant modifications on the macromolecules such as a 40% molecular weight reduction. Degradation appears heterogeneous and limited to the cathode side. The model compound approach developed in the previous article (Perrot et al. [42]) has allowed the identification of the aging path in fuel cell. Phenolic and carboxylic acid chain ends have been identified as the main products resulting from polymer chain scissions. The ex situ lifetime (100 h) of the membrane appears very limited with respect to the in situ operating time suggesting that the low H 2O 2 concentration (0.07%) is still much higher than in fuel cell.

  4. Aryl organophosphate flame retardants induced cardiotoxicity during zebrafish embryogenesis: by disturbing expression of the transcriptional regulators.

    PubMed

    Du, Zhongkun; Wang, Guowei; Gao, Shixiang; Wang, Zunyao

    2015-04-01

    As a result of the ban on some brominated flame retardants (BFRs), the use of organophosphate flame retardants (OPFRs) increases, and they are detected in multi-environment media at higher frequency and concentrations. However, the toxicity data of OPFRs, especially those on developmental toxicology are quite limited, which prevents an accurate evaluation of their environmental and health risk. Because a previous study reported that two aryl-OPFRs induced cardiotoxicity during zebrafish embryogenesis, we designed experiments to compare the heart developmental toxicity of a series of aryl-OPFRs with alkyl-OPFRs and explored possible internal mechanism. First, acute toxicity of 9 frequently used OPFRs were studied with zebrafish embryos (2-96 hpf). By comparing the LC50 and EC50 (pericardium edema) data, two aryl-OPFRs, triphenyl phosphate (TPhP) and cresyl diphenyl phosphate (CDP) showed greater heart developmental toxicity than the others. It was also found that the acute toxicity of OPFRs varied mainly depending on their hydrophobicity. Further study on the cardiotoxicity of TPhP and CDP showed that the cardiac looping progress can be impeded by 0.10mg/L TPhP or CDP exposure. Bradycardia and reduction of myocardium were also observed in 0.50 and 1.0mg/L TPhP groups and 0.10, 0.50, and 1.0mg/L CDP groups. 0-48 hpf is the vulnerable window of zebrafish cardiogenesis that can be easily affected by TPhP and CDP. RT-qPCR measurement on the expressions of key transcriptional regulators in cardiogenesis showed that BMP4, NKX2-5, and TBX5 were significantly inhibited at the exposure points of 12 hpf and 24 hpf which may be the internal factors related to the heart developmental toxicity. As zebrafish is a good model organism for human health study, the present results call for a greater attention to the health risk of fetus in pregnant women exposed to such OPFRs. PMID:25661707

  5. 2-aminopyrimidine-4,6-diol as an efficient ligand for solvent-free copper-catalyzed N-arylations of imidazoles with aryl and heteroaryl halides.

    PubMed

    Xie, Ye-Xiang; Pi, Shao-Feng; Wang, Jian; Yin, Du-Lin; Li, Jin-Heng

    2006-10-13

    Efficient and solvent-free copper-catalyzed N-arylations of imidazoles with aryl and heteroaryl halides have been demonstrated. In the presence of CuBr, 2-aminopyrimidine-4,6-diol, and TBAF (n-Bu4NF), a variety of imidazoles underwent the N-arylation reaction with aryl and heteroaryl halides smoothly in moderate to excellent yields. Noteworthy is that the reaction is conducted under solvent-free conditions. PMID:17025338

  6. Aryl Hydrocarbon Receptor: linking environment to immunity

    PubMed Central

    Cella, Marina; Colonna, Marco

    2015-01-01

    Mucosal and barrier tissues are unique in that they mediate crosstalk between the host and the surrounding environment, which contains many potentially harmful factors. Therefore, it is critical that cell types present at barrier and mucosal surfaces are equipped with mechanisms to sense changes in the environment and to calibrate their responses accordingly. Aryl Hydrocarbon Receptor (AHR) is a ligand dependent transcription factor well known to generate biological responses to environmental pollutants, such as benzo{a}pyrene and halogenated dioxins. Surprisingly, in the last few years a large body of evidence has shown that AHR is also involved in maintaining homeostasis or in triggering pathology by modulating the biological responses of critical cell types at the barrier and mucosal interfaces. Here, we will review progresses in this field and discuss how targeting AHR activation may impact disease. PMID:26561251

  7. Aryl Hydrocarbon Receptor Control of Adaptive Immunity

    PubMed Central

    2013-01-01

    The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that belongs to the family of basic helix-loop-helix transcription factors. Although the AhR was initially recognized as the receptor mediating the pathologic effects of dioxins and other pollutants, the activation of AhR by endogenous and environmental factors has important physiologic effects, including the regulation of the immune response. Thus, the AhR provides a molecular pathway through which environmental factors modulate the immune response in health and disease. In this review, we discuss the role of AhR in the regulation of the immune response, the source and chemical nature of AhR ligands, factors controlling production and degradation of AhR ligands, and the potential to target the AhR for therapeutic immunomodulation. PMID:23908379

  8. Multimetallic Catalysis Enabled Cross-Coupling of Aryl Bromides with Aryl Triflates

    PubMed Central

    Ackerman, Laura K.G.; Lovell, Matthew M.

    2015-01-01

    Transition metal-catalyzed strategies for the formation of new C-C bonds have revolutionized the field of organic chemistry, enabling the efficient synthesis of ligands, materials, and biologically active molecules.1–3 In cases where a single metal fails to promote a selective or efficient transformation, the synergistic cooperation4 of two distinct catalysts – multimetallic catalysis – can be employed instead. Many important reactions rely on multimetallic catalysis,5 including the Wacker oxidation of olefins6–8 and the Sonogashira coupling of alkynes with aryl halides.9–10 However, the application of this strategy, even in recently developed methods11, has largely been limited to the use of metals with distinct reactivities, with only one metal catalyst undergoing an oxidative addition.12 In this manuscript, we demonstrate that cooperativity between two d10 metal catalysts, (bipyridine)nickel and (1,3-bis(diphenylphosphino)propane)palladium, enables a general cross-Ullman reaction.13–15 Our method couples aryl bromides with aryl triflates directly, eliminating the use of arylmetal reagents and avoiding the challenge of differentiating between multiple C–H bonds that is required for many C–H activation methods.16–17 The selectivity does not require an excess of either substrate and originates from the orthogonal activity of the two catalysts and the relative stability of the two arylmetal intermediates. While (dppp)Pd reacts preferentially with aryl triflates to afford a persistent intermediate, (bpy)Ni reacts preferentially with aryl bromides to form a transient, reactive intermediate. Although each catalyst forms less than 5% cross product in isolation, together they are able to achieve up to 94% yield. Our results reveal a new, general method for the synthesis of biaryls, heteroaryls, and dienes, as well as a new mechanism for selective transmetalation between two catalysts. We anticipate that this reaction will simplify the synthesis of

  9. Synthesis of α-Arylphosphonates Using Copper-Catalyzed α-Arylation and Deacylative α-Arylation of β-Ketophosphonates

    PubMed Central

    Rout, Laxmidhar; Regati, Sridhar; Zhao, Cong-Gui

    2011-01-01

    Efficient methods for the direct arylation and deacylative arylation of β-ketophosphonates with iodoarenes in presence of a copper(I) or a copper(II) salt as the catalysts were developed. The corresponding α-arylphosphonates were obtained in high yields. A tentative mechanism for the deacylative arylation reaction was proposed on the basis of the experimental data. PMID:22505878

  10. Chitin nanowhisker-supported sulfonated poly(ether sulfone) proton exchange for fuel cell applications.

    PubMed

    Zhang, Chan; Zhuang, Xupin; Li, Xiaojie; Wang, Wei; Cheng, Bowen; Kang, Weimin; Cai, Zhanjun; Li, Mengqin

    2016-04-20

    To balance the relationship among proton conductivity and mechanic strength of sulfonated poly(ether sulfone) (SPES) membrane, chitin nanowhisker-supported nanocomposite membranes were prepared by incorporating whiskers into SPES. The as-prepared chitin whiskers were prepared by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) mediated oxidation of α-chitin from crab shells. The structure and properties of the composite membranes were examined as proton exchange membrane (PEM). Results showed that chitin nanowhiskers were dispersed incompactly in the SPES matrix. Thermal stability, mechanical properties, water uptake and proton conductivity of the nanocomposite films were improved from those of the pure SPES film with increasing whisker content, which ascribed to strong interactions between whiskers and between SPES molecules and chitin whiskers via hydrogen bonding. These indicated that composition of filler and matrix got good properties and whisker-supported membranes are promising materials for PEM. PMID:26876844

  11. Copper-Catalyzed Carboxylation of Aryl Iodides with Carbon Dioxide.

    PubMed

    Tran-Vu, Hung; Daugulis, Olafs

    2013-10-01

    A method for carboxylation of aryl iodides with carbon dioxide has been developed. The reaction employs low loadings of copper iodide/TMEDA or DMEDA catalyst, 1 atm of CO2, DMSO or DMA solvent, and proceeds at 25-70 °C. Good functional group tolerance is observed, with ester, bromide, chloride, fluoride, ether, hydroxy, amino, and ketone functionalities tolerated. Additionally, hindered aryl iodides such as iodomesitylene can also be carboxylated. PMID:24288654

  12. Chemical and Mechanical Degradation of Sulfonated Poly(sulfone) Membranes in Vanadium Redox Flow Batteries

    SciTech Connect

    Kim, Soowhan; Tighe, Timothy B.; Schwenzer, Birgit; Yan, Jingling; Zhang, Jianlu; Liu, Jun; Yang, Zhenguo; Hickner, Michael A.

    2011-10-01

    A sulfonated poly(sulfone) (S-Radel{reg_sign}) membrane with high proton conductivity and low vanadium ion diffusion showed high initial performance in a vanadium redox flow battery (VRFB) but suffered damage during charge/discharge cycling. The S-Radel membrane had different degradation behaviors in flow cell cycling and ex-situ vanadium ion immersion tests. The S-Radel membrane immersed in V5+ solution cracked into small pieces, but in the VRFB cell, the membrane underwent internal delamination preferentially on the side of the membrane that faced the positive electrode. A vanadium-rich interface was observed near the membrane surface that experienced delamination and Raman spectroscopic analysis of the surfaces of the membrane indicated a slightly depressed 1026 cm-1 band corresponding to the sulfonate SO2 stretch for the degraded surface. Even though the S-Radel membrane underwent severe mechanical damage during the flow cell cycling, significant chemical degradation was not obvious from the spectroscopic analyses. For the VRFB containing an S-Radel membrane, an increase in membrane resistance caused an abnormal voltage depression during the discharge cycle. The reversible increase in membrane resistance and severe mechanical degradation of the membrane during cycling may be attributed repeated formation and dissolution of particles inside the membrane. The mechanical stresses imposed by the particles coupled with a small amount of chemical degradation of the polymer by V5+, are likely degradation mechanisms of the S-Radel membrane in VRFBs under high state-of-charge conditions.

  13. Electrical conductivity of sulfonated poly(ether ether ketone) based composite membranes containing sulfonated polyhedral oligosilsesquioxane

    NASA Astrophysics Data System (ADS)

    Celso, Fabricio; Mikhailenko, Serguei D.; Rodrigues, Marco A. S.; Mauler, Raquel S.; Kaliaguine, Serge

    2016-02-01

    Composite proton exchange membranes (PEMs) intended for fuel cell applications were prepared by embedding of various amounts of dispersed tri-sulfonic acid ethyl POSS (S-Et-POSS) and tri-sulfonic acid butyl POSS (S-Bu-POSS) in thin films of sulfonated poly ether-ether ketone. The electrical properties of the PEMs were studied by Impedance spectroscopy and it was found that their conductivity σ changes with the filler content following a curve with a maximum. The water uptake of these PEMs showed the same dependence. The investigation of initial isolated S-POSS substances revealed the properties of typical electrolytes, which however in both cases possessed low conductivities of 1. 17 × 10-5 S cm-1 (S-Et-POSS) and 3.52 × 10-5 S cm-1 (S-Bu-POSS). At the same time, the insoluble in water S-POSS was found forming highly conductive interface layer when wetted with liquid water and hence producing a strong positive impact on the conductivity of the composite PEM. Electrical properties of the composites were analysed within the frameworks of effective medium theory and bounding models, allowing to evaluate analytically the range of possible conductivity values. It was found that these approaches produced quite good approximation of the experimental data and constituted a fair basis for interpretation of the observed relationship.

  14. Pd-catalyzed divergent trifluoroethylation and arylation of arylboronic acids by aryl(2,2,2-trifluoroethyl)iodonium triflates.

    PubMed

    Yang, Jing; Han, Qiu-Yan; Zhao, Cheng-Long; Dong, Tao; Hou, Zhi-Yuan; Qin, Hua-Li; Zhang, Cheng-Pan

    2016-08-10

    Highly electrophilic aryl(2,2,2-trifluoroethyl)iodonium triflates have been used for the first time as trifluoroethyl and aryl transfer reagents in Pd-catalyzed functionalization of arylboronic acids. Electron-rich arylboronic acids reacted with aryl(2,2,2-trifluoroethyl)iodonium triflates (2a-b) in CH3CN in the presence of Pd2(dba)3 and K3PO4 at room temperature to provide trifluoroethyl arenes in up to 82% yield, while the reactions of both electron-rich and -poor arylboronic acids with 2a-b in DMF in the presence of Pd[P(t-Bu)3]2 and Cs2CO3 at 40 °C afforded arylation products in up to 99% yield. This tunable protocol allows access to trifluoroethyl arenes or biaryls in good to excellent yields under mild conditions and without the addition of extra ligands. PMID:27384263

  15. Palladium-Catalyzed, Ring-Forming Aromatic C–H Alkylations with Unactivated Alkyl Halides

    PubMed Central

    Venning, Alexander R. O.; Bohan, Patrick T.; Alexanian, Erik J.

    2015-01-01

    A catalytic C–H alkylation using unactivated alkyl halides and a variety of arenes and heteroarenes is described. This ring-forming process is successful with a variety of unactivated primary and secondary alkyl halides, including those with β-hydrogens. In contrast to standard polar or radical cyclizations of aromatic systems, electronic activation of the substrate is not required. The mild, catalytic reaction conditions are highly functional group tolerant and facilitate access to a diverse range of synthetically and medicinally important carbocyclic and heterocyclic systems. PMID:25746442

  16. Generation of a structurally diverse library through alkylation and ring closure reactions using 3-dimethylamino-1-(thiophen-2-yl)propan-1-one hydrochloride.

    PubMed

    Roman, Gheorghe

    2013-01-01

    3-Dimethylamino-1-(thiophen-2-yl)propan-1-one hydrochloride (2), a ketonic Mannich base derived from 2-acetylthiophene, was used as a starting material in different types of alkylation and ring closure reactions with a view to generate a structurally diverse library of compounds. Compound 2 reacts with S-alkylated dithiocarbamic acid salts and aryl mercaptans to produce dithiocarbamates and thioethers, respectively. The dimethylamino moiety in compound 2 was exchanged with various aliphatic secondary and aromatic primary and secondary amines, whereas monocyclic NH-azoles such as pyrazole, imidazole, 1,2,4-triazole, and tetrazole were N-alkylated by compound 2. Ketones, pyrrole and indoles have been the substrates subjected to C-alkylation reactions by compound 2. Ring closure reactions of compound 2 with a suitable bifunctional nucleophile yielded pyrazolines, pyridines, 2,3-dihydro-1,5-1H-benzodiazepines, 2,3-dihydro-1,5-1H-benzothiazepine, pyrimido[1,2-a]benzimidazole and 4-hydroxypiperidine derivatives. PMID:23841334

  17. Sulfonated-polyethyleneimine for Photosensitizer Conjugation and Targeting

    PubMed Central

    Chitgupi, Upendra; Zhang, Yumiao; Lo, Chi Y.; Shao, Shuai; Song, Wentao; Geng, Jumin; Neelamegham, Sriram; Lovell, Jonathan F.

    2015-01-01

    Polysulfonated macromolecules are known to bind selectins, adhesion membrane proteins which are broadly implicated in inflammation. Commercially available branched polyethyleneimine (PEI) was reacted with chlorosulfonic acid to generate sulfonated PEI with varying degrees of sulfonation. Remaining unreacted amine groups were then used for straightforward conjugation with pyropheophoribide-a, a near infrared photosensitizer. Photosensitizer-labeled sulfonated PEI conjugates inhibited blood coagulation and were demonstrated to specifically bind to cells genetically programmed to overexpress L-selectin (CD62L) or P-selectin (CD62P). In vitro, following targeting, selectin-expressing cells could be destroyed via photodynamic therapy. PMID:26057017

  18. Enhancement of alkylation catalysts for improved supercritical fluid regeneration

    DOEpatents

    Ginosar, Daniel M.; Petkovic, Lucia

    2009-09-22

    A method of modifying an alkylation catalyst to reduce the formation of condensed hydrocarbon species thereon. The method comprises providing an alkylation catalyst comprising a plurality of active sites. The plurality of active sites on the alkylation catalyst may include a plurality of weakly acidic active sites, intermediate acidity active sites, and strongly acidic active sites. A base is adsorbed to a portion of the plurality of active sites, such as the strongly acidic active sites, selectively poisoning the strongly acidic active sites. A method of modifying the alkylation catalyst by providing an alkylation catalyst comprising a pore size distribution that sterically constrains formation of the condensed hydrocarbon species on the alkylation catalyst or by synthesizing the alkylation catalyst to comprise a decreased number of strongly acidic active sites is also disclosed, as is a method of improving a regeneration efficiency of the alkylation catalyst.

  19. Enhancement of alkylation catalysts for improved supercritical fluid regeneration

    DOEpatents

    Ginosar, Daniel M.; Petkovic, Lucia M.

    2010-12-28

    A method of modifying an alkylation catalyst to reduce the formation of condensed hydrocarbon species thereon. The method comprises providing an alkylation catalyst comprising a plurality of active sites. The plurality of active sites on the alkylation catalyst may include a plurality of weakly acidic active sites, intermediate acidity active sites, and strongly acidic active sites. A base is adsorbed to a portion of the plurality of active sites, such as the strongly acidic active sites, selectively poisoning the strongly acidic active sites. A method of modifying the alkylation catalyst by providing an alkylation catalyst comprising a pore size distribution that sterically constrains formation of the condensed hydrocarbon species on the alkylation catalyst or by synthesizing the alkylation catalyst to comprise a decreased number of strongly acidic active sites is also disclosed, as is a method of improving a regeneration efficiency of the alkylation catalyst.

  20. Measured and predicted affinities of binding and relative potencies to activate the AhR of PAHs and their alkylated analogues.

    PubMed

    Lee, Sangwoo; Shin, Woong-Hee; Hong, Seongjin; Kang, Habyeong; Jung, Dawoon; Yim, Un Hyuk; Shim, Won Joon; Khim, Jong Seong; Seok, Chaok; Giesy, John P; Choi, Kyungho

    2015-11-01

    Polycyclic aromatic hydrocarbons (PAHs) and their alkylated forms are important components of crude oil. Both groups of PAHs have been reported to cause dioxin-like responses, mediated by aryl hydrocarbon receptor (AhR). Thus, characterization of binding affinity to the AhR of unsubstituted or alkylated PAHs is important to understand the toxicological consequences of oil contamination on ecosystems. We investigated the potencies of major PAHs of crude oil, e.g., chrysene, phenanthrene and dibenzothiophene, and their alkylated forms (n=17) to upregulate expression of AhR-mediated processes by use of the H4IIE-luc transactivation bioassay. In addition, molecular descriptors of different AhR activation potencies among PAHs were investigated by use of computational molecular docking models. Based on responses of the H4IIE-luc in vitro assay, it was shown that potencies of PAHs were determined by alkylation in addition to the number and conformation of rings. Potencies of AhR-mediated processes were generally greater when a chrysene group was substituted, especially in 1-methyl-chrysene. Significant negative correlations were observed between the in vitro dioxin-like potency measured in H4IIE-luc cells and the binding distance estimated from the in silico modeling. The difference in relative potency for AhR activation observed among PAHs and their alkylated forms could be explained by differences among binding distances in the ligand binding domain of the AhR caused by alkylation. The docking model developed in the present study may have utility in predicting risks of environmental contaminants of which toxicities are mediated by AhR binding. PMID:26037956

  1. Reversed-Polarity Synthesis of Diaryl Ketones through Palladium-Catalyzed Direct Arylation of 2-Aryl-1,3-dithianes

    PubMed Central

    Yucel, Baris; Walsh, Patrick J.

    2015-01-01

    An umpolung approach to the synthesis of diaryl ketones has been developed based on in situ generation of acyl anion equivalents and their catalytic arylation. This method entails the base promoted palladium catalyzed direct C–H arylation of 2 The resulting 2,2-diaryl-1,3-dithianes with aryl bromides. Use of MN(SiMe3)2 (M=Li, Na) base results in reversible deprotonation of the weakly acidic dithiane. In the presence of a Pd(NiXantphos)-based catalyst and aryl bromide, cross-coupling of the metallated 2-aryl-1,3-dithiane takes place under mild conditions (2 h at rt) with yields as high as 96%. The resulting 2,2-diaryl-1,3-dithianes were converted into diaryl ketones by either molecular iodine, N-bromo succinimide (NBS) or Selectfluor in the presence of water. The dithiane arylation/hydrolysis can be performed in a one-pot procedure to yield a good to excellent yields. This method is suitable for rapid and large-scale synthesis of diaryl ketones. A one-pot preparation of anti-cholesterol drug fenofibrate (TriCor®) has been achieved on 10.0 mmol scale in 86% yield. PMID:26185491

  2. Electrochemical Windows of Sulfone-Based Electrolytes for High-Voltage Li-Ion Batteries

    SciTech Connect

    Shao, Nan; Sun, Xiao-Guang; Dai, Sheng; Jiang, Deen

    2011-01-01

    Further development of high-voltage lithium-ion batteries requires electrolytes with electrochemical windows greater than 5 V. Sulfone-based electrolytes are promising for such a purpose. Here we compute the electrochemical windows for experimentally tested sulfone electrolytes by different levels of theory in combination with various solvation models. The MP2 method combined with the polarizable continuum model is shown to be the most accurate method to predict oxidation potentials of sulfone-based electrolytes with mean deviation less than 0.29 V. Mulliken charge analysis shows that the oxidation happens on the sulfone group for ethylmethyl sulfone and tetramethylene sulfone, and on the ether group for ether functionalized sulfones. Large electrochemical windows of sulfone-based electrolytes are mainly contributed by the sulfone group in the molecules which helps lower the HOMO level. This study can help understand the voltage limits imposed by the sulfone-based electrolytes and aid in designing new electrolytes with greater electrochemical windows.

  3. Comparison of Diffusion Coefficients of Aryl Carbonyls and Aryl Alcohols in Hydroxylic Solvents. Evidence that the Diffusion of Ketyl Radicals in Hydrogen-Bonding Solvents is Not Anomalous?

    SciTech Connect

    Autrey, S Thomas ); Camaioni, Donald M. ); Kandanarachchi, Pramod H.; Franz, James A. )

    2000-12-01

    The diffusion coefficients of a benzyl-, sec-phenethyl-, and diphenylmethyl alcohol and the corresponding aryl carbonyls (benzaldehyde, acetophenone and benzophenone) were measured by Taylor's dispersion method in both ethyl and isopropyl alcohol. The experimental values are compared to published transient grating measurements of the corresponding aryl ketyl radicals (benzyl-, sec-phenethyl-, and diphenylmethyl-ketyl radical). In general, the diffusion coefficient of the aryl alcohols and the corresponding aryl ketyl radicals are equivalent within experimental error. This work shows that the diffusion of ketyl radicals is not anomalously slow and that aryl alcohols are significantly better models than the corresponding aryl ketones for analyzing the diffusion of aryl ketyl radicals in both ethyl and isopropyl alcohol. Empirical estimates of the diffusion coefficients of aryl alcohols using the Spernol-Wirtz and Wilke-Chang modifications to the Stokes-Einstein diffusion equation do not adequately account for the interactions between the aryl ketyl radicals or aryl alcohols with the hydroxylic solvents ethyl and isopropyl alcohol. The excellent agreement between the experimental diffusion coefficients of the aryl alcohols and the corresponding ketyl radicals show that the transient grating method can provide accurate estimates for the diffusion coefficients of transient species. This is especially important when a stable model is not available, for example the pyranyl radical.

  4. Ionic Liquid-Induced Unprecedented Size Enhancement of Aggregates within Aqueous Sodium Dodecylbenzene Sulfonate

    SciTech Connect

    Rai, Rewa; Baker, Gary A; Behera, Kamalakanta; Mohanty, Pravakar; Kurur, Narayanan; Pandey, Siddharth

    2010-01-01

    Physicochemical properties of aqueous micellar solutions may change in the presence of ionic liquids (ILs). Micelles help to increase the aqueous solubility of ILs. The average size of the micellar aggregates within aqueous sodium dodecylbenzene sulfonate (SDBS) is observed by dynamic light scattering (DLS) and transmission electron microscopy (TEM) to increase in a sudden and drastic fashion as the IL 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) is added. Similar addition of [bmim][PF6] to aqueous sodium dodecyl sulfate (SDS) results in only a slow gradual increase in average aggregate size. While addition of the IL [bmim][BF4] also gives rise to sudden aggregate size enhancement within aqueous SDBS, the IL 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]), and inorganic salts NaPF6 and NaBF4, only gradually increase the assembly size upon their addition. Bulk dynamic viscosity, microviscosity, dipolarity (indicated by the fluorescent reporter pyrene), zeta potential, and electrical conductance measurements were taken to gain insight into this unusual size enhancement. It is proposed that bmim cations of the IL undergo Coulombic attractive interactions with anionic headgroups at the micellar surface at all [bmim][PF6] concentrations in aqueous SDS; in aqueous SDBS, beyond a critical IL concentration, bmim becomes involved in cation- interaction with the phenyl moiety of SDBS within micellar aggregates with the butyl group aligned along the alkyl chain of the surfactant. This relocation of bmim results in an unprecedented size increase in micellar aggregates. Aromaticity of the IL cation alongside the presence of sufficiently aliphatic (butyl or longer) alkyl chains on the IL appear to be essential for this dramatic critical expansion in self-assembly dimensions within aqueous SDBS.

  5. Novel S1P1 receptor agonists - Part 4: Alkylaminomethyl substituted aryl head groups.

    PubMed

    Lescop, Cyrille; Müller, Claus; Mathys, Boris; Birker, Magdalena; de Kanter, Ruben; Kohl, Christopher; Hess, Patrick; Nayler, Oliver; Rey, Markus; Sieber, Patrick; Steiner, Beat; Weller, Thomas; Bolli, Martin H

    2016-06-30

    In a previous communication we reported on the discovery of alkylamino pyridine derivatives (e.g. 1) as a new class of potent, selective and efficacious S1P1 receptor (S1PR1) agonists. However, more detailed profiling revealed that this compound class is phototoxic in vitro. Here we describe a new class of potent S1PR1 agonists wherein the exocyclic nitrogen was moved away from the pyridine ring (e.g. 11c). Further structural modifications led to the identification of novel alkylaminomethyl substituted phenyl and thienyl derivatives as potent S1PR1 agonists. These new alkylaminomethyl aryl compounds showed no phototoxic potential. Based on their in vivo efficacy and ability to penetrate the brain, the 5-alkyl-aminomethyl thiophenes appeared to be the most interesting class. Potent and selective S1PR1 agonist 20e, for instance, maximally reduced the blood lymphocyte count (LC) for 24 h after oral administration of 10 mg/kg to rat and its brain concentrations reached >500 ng/g over 24 h. PMID:27061986

  6. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  7. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  8. 40 CFR 721.575 - Substituted alkyl halide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted alkyl halide. 721.575... Substances § 721.575 Substituted alkyl halide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as substituted alkyl halide (PMN P-83-1222)...

  9. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  10. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  11. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  12. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  13. 40 CFR 721.555 - Alkyl amino nitriles (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Substances § 721.555 Alkyl amino nitriles (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as alkyl amino nitriles (PMNs P-96... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl amino nitriles (generic)....

  14. 40 CFR 721.3485 - Hydrofluorocarbon alkyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Hydrofluorocarbon alkyl ether. 721... Substances § 721.3485 Hydrofluorocarbon alkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a hydrofluorocarbon alkyl...

  15. 40 CFR 721.3485 - Hydrofluorocarbon alkyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hydrofluorocarbon alkyl ether. 721... Substances § 721.3485 Hydrofluorocarbon alkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a hydrofluorocarbon alkyl...

  16. 40 CFR 721.10053 - Alkyl silane methacrylate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl silane methacrylate (generic... Specific Chemical Substances § 721.10053 Alkyl silane methacrylate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl...

  17. 40 CFR 721.10053 - Alkyl silane methacrylate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl silane methacrylate (generic... Specific Chemical Substances § 721.10053 Alkyl silane methacrylate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl...

  18. 40 CFR 721.10053 - Alkyl silane methacrylate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl silane methacrylate (generic... Specific Chemical Substances § 721.10053 Alkyl silane methacrylate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl...

  19. 40 CFR 721.10053 - Alkyl silane methacrylate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl silane methacrylate (generic... Specific Chemical Substances § 721.10053 Alkyl silane methacrylate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl...

  20. 40 CFR 721.10053 - Alkyl silane methacrylate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl silane methacrylate (generic... Specific Chemical Substances § 721.10053 Alkyl silane methacrylate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl...

  1. 40 CFR 721.555 - Alkyl amino nitriles (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Substances § 721.555 Alkyl amino nitriles (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as alkyl amino nitriles (PMNs P-96... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl amino nitriles (generic)....

  2. IONIC LIQUID-CATALYZED ALKYLATION OF ISOBUTANE WITH 2-BUTENE

    EPA Science Inventory

    A detailed study of the alkylation of isobutane with 2-butene in ionic liquid media has been conducted using 1-alkyl-3-methylimidazolium halides?aluminum chloride encompassing various alkyl groups (butyl-, hexyl-, and octyl-) and halides (Cl, Br, and I) on its cations and anions,...

  3. 40 CFR 721.1852 - Di-alkyl borane (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Di-alkyl borane (generic). 721.1852... Substances § 721.1852 Di-alkyl borane (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as di-alkyl borane (PMN P-00-1087) is...

  4. 40 CFR 721.10087 - Substituted alkyl phosphine oxide (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted alkyl phosphine oxide... Specific Chemical Substances § 721.10087 Substituted alkyl phosphine oxide (generic). (a) Chemical... as substituted alkyl phosphine oxide (PMN P-06-332) is subject to reporting under this section...

  5. 40 CFR 721.10087 - Substituted alkyl phosphine oxide (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Substituted alkyl phosphine oxide... Specific Chemical Substances § 721.10087 Substituted alkyl phosphine oxide (generic). (a) Chemical... as substituted alkyl phosphine oxide (PMN P-06-332) is subject to reporting under this section...

  6. 40 CFR 721.9720 - Disubstituted alkyl triazines (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Disubstituted alkyl triazines (generic... Specific Chemical Substances § 721.9720 Disubstituted alkyl triazines (generic name). (a) Chemical... as disubstituted alkyl triazines (PMNs P-85-932 and P-85-933) are subject to reporting under...

  7. 40 CFR 721.10506 - Alkylated phenols (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkylated phenols (generic). 721.10506... Substances § 721.10506 Alkylated phenols (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as alkylated phenols (PMNs...

  8. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  9. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  10. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  11. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  12. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  13. 40 CFR 721.10506 - Alkylated phenols (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkylated phenols (generic). 721.10506... Substances § 721.10506 Alkylated phenols (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as alkylated phenols (PMNs...

  14. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  15. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  16. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  17. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  18. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  19. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  20. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  1. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  2. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  3. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  4. 40 CFR 721.4136 - Alkyl heteropolycyclic-aniline (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl heteropolycyclic-aniline... Specific Chemical Substances § 721.4136 Alkyl heteropolycyclic-aniline (generic). (a) Chemical substance... alkyl heteropolycyclic-aniline (PMN P-00-0067) is subject to reporting under this section for...

  5. 40 CFR 721.4136 - Alkyl heteropolycyclic-aniline (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl heteropolycyclic-aniline... Specific Chemical Substances § 721.4136 Alkyl heteropolycyclic-aniline (generic). (a) Chemical substance... alkyl heteropolycyclic-aniline (PMN P-00-0067) is subject to reporting under this section for...

  6. 40 CFR 721.4136 - Alkyl heteropolycyclic-aniline (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl heteropolycyclic-aniline... Specific Chemical Substances § 721.4136 Alkyl heteropolycyclic-aniline (generic). (a) Chemical substance... alkyl heteropolycyclic-aniline (PMN P-00-0067) is subject to reporting under this section for...

  7. 40 CFR 721.4136 - Alkyl heteropolycyclic-aniline (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl heteropolycyclic-aniline... Specific Chemical Substances § 721.4136 Alkyl heteropolycyclic-aniline (generic). (a) Chemical substance... alkyl heteropolycyclic-aniline (PMN P-00-0067) is subject to reporting under this section for...

  8. 40 CFR 721.4136 - Alkyl heteropolycyclic-aniline (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl heteropolycyclic-aniline... Specific Chemical Substances § 721.4136 Alkyl heteropolycyclic-aniline (generic). (a) Chemical substance... alkyl heteropolycyclic-aniline (PMN P-00-0067) is subject to reporting under this section for...

  9. Synthesis and characterization of chitosan alkyl urea.

    PubMed

    Wang, Jing; Jiang, Ji-Zhou; Chen, Wei; Bai, Zheng-Wu

    2016-07-10

    Chitosan is a versatile material employed for various purposes in many fields including the development of chiral stationary phases for enantioseparation. Chitosan alkyl urea is a kind of intermediate used to prepare enantioseparation materials. In order to synthesize the intermediates, in the present work, a new way to prepare chitosan alkyl urea has been established: chitosan was first reacted with methyl chloroformate yielding N-methoxyformylated chitosan, which was then converted to chitosan alkyl urea through amine-ester exchange reaction. With a large excess of methyl chloroformate and primary amine of low stereohindrance, the amino group in chitosan could be almost completely converted to ureido group. The as-prepared chitosan alkyl urea derivatives were characterized by IR, (1)H NMR, (13)C NMR,(1)H-(1)H COSY and (1)H-(13)C HSQC NMR spectra. The chemical shifts of hydrogen and carbon atoms of glucose unit were assigned. It was found that the degree of substitution was obviously lower if cyclopropyl amine, aniline, tert-butyl amine and diethyl amine were used as reactants for the amine-ester exchange reaction. The reason was explained with the aid of theoretical calculations. PMID:27106154

  10. Poly(ethyleneoxide) functionalization through alkylation

    SciTech Connect

    Sivanandan, Kulandaivelu; Eitouni, Hany Basam; Li, Yan; Pratt, Russell Clayton

    2015-04-21

    A new and efficient method of functionalizing high molecular weight polymers through alkylation using a metal amide base is described. This novel procedure can also be used to synthesize polymer-based macro-initiators containing radical initiating groups at the chain-ends for synthesis of block copolymers.

  11. Polygas spells relief from alkylation ills

    SciTech Connect

    Weismantel, G.E.

    1980-06-16

    Tight supplies and soaring prices of isobutane (for olefin alkylation), are causing renewed interest in the olefin ''polymerization'' (i.e., dimerization), route to high-octane gasoline-blending components. Modern polymerization processes, intended to supplement rather than replace alkylation offer considerable energy and capital savings, compared with alkylation-only schemes. In addition to the Institut Francais du Petrole's Dimersol ''polymerization'' tecnique which is already being used or will be used by 1981 in at least five U.S. refineries, with six more units in the planning stage, a low-cost process to ''polymerize'' excess refinery olefins, developed by International Energy Consultants Inc., is nearing commercialization. A third route to process C/sub 3//C/sub 4/ refinery streams with high conversion rates has been proposed by UOP Inc. The low motor octane number (MON) of the product gasoline (approx. 13 numbers lower than a typical alkylate), was recently confirmed in Total Petroleum Inc.'s studies, but Good Hope Refineries Inc. plans to increase its polymer gasoline MON by adding methyl tert.-butyl ether.

  12. Separate olefin processing in sulfuric acid alkylation

    SciTech Connect

    Imhoff, S.A.; Graves, D.C.

    1995-09-01

    This paper will discuss the effects of alkylating propylene, butylenes and amylenes together and suggest alternative processing schemes which will minimize the negative synergies, improve octane and/or minimize acid consumption. The first option will show the impact of segregating the propylene and amylenes. In the second option, the benefit of alkylating the individual olefins at their optimal acid strengths will be presented. Additionally, each olefin`s optimal reaction conditions will be examined. Unfortunately, many refiners may not have the existing flexibility to take advantage of separate olefin processing. First, the majority of the propylene, butylenes and amylenes must be separate upon entry to the alkylation unit. If the olefins cannot be segregated upstream, separate olefin processing will not be as beneficial. If this is the case, then the benefits of separate olefin processing will have to be weighed versus the capital and energy costs required to separate them. In addition, small units may not have sufficient numbers of Contactors and settlers to achieve adequate segregation. Later in this paper, the modifications required in the alkylation unit for separate olefin processing will be discussed.

  13. Synthesis and evaluation of antitubercular activity of fluorinated 5-aryl-4-(hetero)aryl substituted pyrimidines.

    PubMed

    Verbitskiy, Egor V; Baskakova, Svetlana A; Kravchenko, Marionella A; Skornyakov, Sergey N; Rusinov, Gennady L; Chupakhin, Oleg N; Charushin, Valery N

    2016-08-15

    Various 5-(fluoroaryl)-4-(hetero)aryl substituted pyrimidines have been synthesized based on the Suzuki cross-coupling and nucleophilic aromatic substitution of hydrogen (SN(H)) reactions starting from commercially available 5-bromopyrimidine and their antitubercular activity against Mycobacterium tuberculosis H37Rv has been explored. The outcome of the study disclose that, some of the compounds have showed promising activity in micromolar concentration against Mycobacterium tuberculosis H37Rv, Mycobacterium avium, Mycobacterium terrae, and multidrug-resistant strains isolated from tuberculosis patients in Ural region (Russia). The data concerning the 'structure-activity' relationship for fluorinated compounds have been discussed. PMID:27338658

  14. Proposal for halogen atom transfer mechanism for Ullmann O-arylation of phenols with aryl halides.

    PubMed

    Zhang, Songlin; Zhu, Zhenzhong; Ding, Yuqiang

    2012-12-01

    A systematic theoretical study on reaction mechanisms for copper(I)-catalyzed C-O coupling of phenols with aryl bromides is reported herein. Through evaluation of the relative concentrations of possible copper species in reaction solution and reactivity study of these copper species with aryl halides in the context of several commonly proposed mechanisms for copper(I)-catalyzed Ullmann reactions, we propose that the active copper catalyst should be a neutral (L)Cu(I)-OAr (L denotes an ancillary ligand; OAr denotes an aryloxide ligand) species in nonpolar solvent and Cu(OAr)(2)(-) anion in highly polar solvent. In the reaction solution, these two kinds of copper species should be in equilibrium, the direction of which is highly dependent on the polarity of the solvent. For both kinds of copper species, a halogen atom transfer mechanism is favored where an initial halogen atom transfer from phenyl bromide to the Cu(I) center occurs, resulting in the formation of Cu(II)(OAr)(Br) and a phenyl radical. Subsequent rapid attack of this phenyl radical to the aryloxide ligand bound to copper(II) would yield the coupling product and Cu(I)(Br) species, which can be readily converted to the active Cu(I)-OAr species in the presence of phenols and base. Other mechanisms such as oxidative addition, single electron transfer and σ-bond metathesis mechanisms all possess activation barriers which are too high, rendering them kinetically unfavorable. Electronic effects on phenol rings reveal that electron-donating substituents accelerate the coupling of (phen)Cu(I)(OAr) with aryl halides whereas electron-withdrawing substituents lead to much higher activation barriers, which is consistent with experimental findings and thus lends further support for such a halogen atom transfer mechanism. In view of the widely accepted oxidative addition/reductive elimination mechanism for analogous copper(I)-catalyzed coupling of N-nucleophiles with aryl halides, our results here highlight that the

  15. Affinity labelling enzymes with esters of aromatic sulfonic acids

    DOEpatents

    Wong, Show-Chu; Shaw, Elliott

    1977-01-01

    Novel esters of aromatic sulfonic acids are disclosed. The specific esters are nitrophenyl p- and m-amidinophenylmethanesulfonate. Also disclosed is a method for specific inactivation of the enzyme, thrombin, employing nitrophenyl p-amidinophenylmethanesulfonate.

  16. Interrogating alkyl and arylalkylpolyamino (bis)urea and (bis)thiourea isosteres as potent antimalarial chemotypes against multiple lifecycle forms of Plasmodium falciparum parasites

    PubMed Central

    Verlinden, Bianca K.; de Beer, Marna; Pachaiyappan, Boobalan; Besaans, Ethan; Andayi, Warren A.; Reader, Janette; Niemand, Jandeli; van Biljon, Riette; Guy, Kiplin; Egan, Timothy; Woster, Patrick M.; Birkholtz, Lyn-Marie

    2015-01-01

    A new series of potent potent aryl/alkylated (bis)urea- and (bis)thiourea polyamine analogues were synthesized and evaluated in vitro for their antiplasmodial activity. Altering the carbon backbone and terminal substituents increased the potency of analogues in the compound library 3-fold, with the most active compounds, 15 and 16, showing half-maximal inhibitory concentrations (IC50 values) of 28 and 30 nM, respectively, against various Plasmodium falciparum parasite strains without any cross-resistance. In vitro evaluation of the cytotoxicity of these analogues revealed marked selectivity towards targeting malaria parasites compared to mammalian HepG2 cells (>5000-fold lower IC50 against the parasite). Preliminary biological evaluation of the polyamine analogue antiplasmodial phenotype revealed that (bis)urea compounds target parasite asexual proliferation, whereas (bis)thiourea compounds of the same series have the unique ability to block transmissible gametocyte forms of the parasite, indicating pluripharmacology against proliferative and non-proliferative forms of the parasite. In this manuscript, we describe these results and postulate a refined structure-activity relationship (SAR) model for antiplasmodial polyamine analogues. The terminally aryl/alkylated (bis)urea- and (bis)thiourea-polyamine analogues featuring a 3-5-3 or 3-6-3 carbon backbone represent a structurally novel and distinct class of potential antiplasmodials with activities in the low nanomolar range, and high selectivity against various lifecycle forms of P. falciparum parasites. PMID:25684422

  17. Interrogating alkyl and arylalkylpolyamino (bis)urea and (bis)thiourea isosteres as potent antimalarial chemotypes against multiple lifecycle forms of Plasmodium falciparum parasites.

    PubMed

    Verlinden, Bianca K; de Beer, Marna; Pachaiyappan, Boobalan; Besaans, Ethan; Andayi, Warren A; Reader, Janette; Niemand, Jandeli; van Biljon, Riette; Guy, Kiplin; Egan, Timothy; Woster, Patrick M; Birkholtz, Lyn-Marie

    2015-08-15

    A new series of potent potent aryl/alkylated (bis)urea- and (bis)thiourea polyamine analogues were synthesized and evaluated in vitro for their antiplasmodial activity. Altering the carbon backbone and terminal substituents increased the potency of analogues in the compound library 3-fold, with the most active compounds, 15 and 16, showing half-maximal inhibitory concentrations (IC50 values) of 28 and 30 nM, respectively, against various Plasmodium falciparum parasite strains without any cross-resistance. In vitro evaluation of the cytotoxicity of these analogues revealed marked selectivity towards targeting malaria parasites compared to mammalian HepG2 cells (>5000-fold lower IC50 against the parasite). Preliminary biological evaluation of the polyamine analogue antiplasmodial phenotype revealed that (bis)urea compounds target parasite asexual proliferation, whereas (bis)thiourea compounds of the same series have the unique ability to block transmissible gametocyte forms of the parasite, indicating pluripharmacology against proliferative and non-proliferative forms of the parasite. In this manuscript, we describe these results and postulate a refined structure-activity relationship (SAR) model for antiplasmodial polyamine analogues. The terminally aryl/alkylated (bis)urea- and (bis)thiourea-polyamine analogues featuring a 3-5-3 or 3-6-3 carbon backbone represent a structurally novel and distinct class of potential antiplasmodials with activities in the low nanomolar range, and high selectivity against various lifecycle forms of P. falciparum parasites. PMID:25684422

  18. Triple Activity of Lamivudine Releasing Sulfonated Polymers against HIV-1.

    PubMed

    Danial, Maarten; Andersen, Anna H F; Zuwala, Kaja; Cosson, Steffen; Riber, Camilla Frich; Smith, Anton A A; Tolstrup, Martin; Moad, Graeme; Zelikin, Alexander N; Postma, Almar

    2016-07-01

    In this article a library of polymeric therapeutic agents against the human immunodeficiency virus (HIV) is presented. The library of statistical copolymers of varied molar mass was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. The synthesized polymers comprise pendent hydroxyl and sulfonated side chains as well as the reverse transcriptase prodrug lamivudine (3TC) attached via a disulfide self-immolative linker. The glutathione mediated release of 3TC is demonstrated as well as the antiviral efficacy against HIV entry and polymerase activity. Although a high degree of polymer sulfonation is required for effective HIV entry inhibition, polymers with approximately ∼50% sulfonated monomer demonstrated potent kinase independent reverse transcriptase inhibition. In addition, the sulfonated polymers demonstrate activity against DNA-DNA polymerase, which suggests that these polymers may exhibit activity against a broad spectrum of viruses. In summary, the polymers described provide a triple-active arsenal against HIV with extracellular activity via entry inhibition and intracellular activity by kinase-dependent lamivudine-based and kinase-independent sulfonated polymer based inhibition. Since these sulfonated copolymers are easily formulated into gels, we envision them to be particularly suited for topical application to prevent the mucosal transmission of viruses, particularly HIV. PMID:27244595

  19. Characterization of a Sulfonated Polycarbonate Resistive Humidity Sensor

    PubMed Central

    Rubinger, Carla P.L.; Calado, Hallen D.R.; Rubinger, Rero M.; Oliveira, Henrique; Donnici, Claudio L.

    2013-01-01

    In this work; resistive moisture sensors were obtained by dip coating sulfonated polycarbonate (SPC) onto silver interdigitated electrodes. Commercial polycarbonate was sulfonated with acetyl sulphate at two different sulfonation degrees corresponding to 9.0 and 18.0 mole %. Impedance spectroscopy was used to investigate the humidity sensing properties at controlled relative humidity (RH%) environments generated from standard saline solutions in the range of 11–90 RH%. For the highest sulfonated sample; in the RH% range investigated (11 to 90%); the sensor impedance changed from 4.7 MΩ to 18 kΩ. Humidity sensors made from sulfonated polycarbonate showed exponential decay behavior of the impedance at constant frequency with the environmental relative humidity. Sample 9SPC presented dielectric relaxation response for environmental humidity between 58 and 90 RH% while sample 18SPC presented dielectric relaxation response for the entire measured range between 11 and 90 RH%. Sulfonated polycarbonate could be a promising material for the fabrication of simple and cheap humidity-sensing sensors for the assessment of relative humidity of the surrounding environment, as suggested by experimental results. PMID:23385415

  20. β-Cyclodextrin-Propyl Sulfonic Acid Catalysed One-Pot Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles as Local Anesthetic Agents.

    PubMed

    Ran, Yan; Li, Ming; Zhang, Zong-Ze

    2015-01-01

    Some functionalized 1,2,4,5-tetrasubstituted imidazole derivatives were synthesized using a one-pot, four component reaction involving 1,2-diketones, aryl aldehydes, ammonium acetate and substituted aromatic amines. The synthesis has been efficiently carried out in a solvent free medium using β-cyclodextrin-propyl sulfonic acid as a catalyst to afford the target compounds in excellent yields. The local anesthetic effect of these derivatives was assessed in comparison to lidocaine as a standard using a rabbit corneal and mouse tail anesthesia model. The three most potent promising compounds were subjected to a rat sciatic nerve block assay where they showed considerable local anesthetic activity, along with minimal toxicity. Among the tested analogues, 4-(1-benzyl-4,5-diphenyl-1H-imidazol-2-yl)-N,N-dimethylaniline (5g) was identified as most potent analogue with minimal toxicity. It was further characterized by a more favourable therapeutic index than the standard. PMID:26569210

  1. Dichloromethyl alkyl ethers and sulfides in the Reformatskii reaction

    SciTech Connect

    Lapkin, I.I.; Fotin, V.V.

    1986-09-10

    A study was carried out on the reaction of dichloromethyl alkyl ethers and sulfides with ..cap alpha..-brominated esters in the presence of zinc resulting in the formation of either ..cap alpha..-alkyl-..beta..-alkoxyacrylates (or ..cap alpha..-alkyl-..beta..-alkylthioacrylates) or ..cap alpha..,..cap alpha..,..cap alpha..',..cap alpha..'-tetramethyl-..beta..-alkoxyglutaric acid (or ..cap alpha..,..cap alpha..,..cap alpha..',..cap alpha..'-tetramethyl-..beta..-alkylthioglutaric acid) depending on the structure of the starting bromoester. PMR and IR spectroscopy indicates the geometry of the ..cap alpha..-alkyl-..beta..-alkoxyacrylates and ..cap alpha..-alkyl-..beta..-alkylthioacrylates.

  2. Control of Reactivity and Regioselectivity for On-Surface Dehydrogenative Aryl-Aryl Bond Formation.

    PubMed

    Kocić, Nemanja; Liu, Xunshan; Chen, Songjie; Decurtins, Silvio; Krejčí, Ondřej; Jelínek, Pavel; Repp, Jascha; Liu, Shi-Xia

    2016-05-01

    Regioselectivity is of fundamental importance in chemical synthesis. Although many concepts for site-selective reactions are well established for solution chemistry, it is not a priori clear whether they can easily be transferred to reactions taking place on a metal surface. A metal will fix the chemical potential of the electrons and perturb the electronic states of the reactants because of hybridization. Additionally, techniques to characterize chemical reactions in solution are generally not applicable to on-surface reactions. Only recent developments in resolving chemical structures by atomic force microscopy (AFM) and scanning tunneling microscopy (STM) paved the way for identifying individual reaction products on surfaces. Here we exploit a combined STM/AFM technique to demonstrate the on-surface formation of complex molecular architectures built up from a heteroaromatic precursor, the tetracyclic pyrazino[2,3-f][4,7]phenanthroline (pap) molecule. Selective intermolecular aryl-aryl coupling via dehydrogenative C-H activation occurs on Au(111) upon thermal annealing under ultrahigh vacuum (UHV) conditions. A full atomistic description of the different reaction products based on an unambiguous discrimination between pyrazine and pyridine moieties is presented. Our work not only elucidates that ortho-hydrogen atoms of the pyrazine rings are preferentially activated over their pyridine equivalents, but also sheds new light onto the participation of substrate atoms in metal-organic coordination bonding during covalent C-C bond formation. PMID:27059121

  3. Electrocatalytic activities of cathode electrodes for water electrolysis using tetra-alkyl-ammonium-sulfonic acid ionic liquid as electrolyte

    NASA Astrophysics Data System (ADS)

    Fiegenbaum, Fernanda; de Souza, Michèle O.; Becker, Márcia R.; Martini, Emilse M. A.; de Souza, Roberto F.

    2015-04-01

    The hydrogen evolution reaction (HER) performed with platinum (Pt), nickel (Ni), stainless steel 304 (SS) or glassy carbon (GC) cathodes in 0.1 M 3-triethylammonium-propanesulfonic acid tetrafluoroborate (TEA-PS.BF4) solution is studied using quasi-potentiostatic and impedance spectroscopy techniques. The objective is to compare the catalytic effect on the cathode using different materials to obtain hydrogen by water electrolysis. Furthermore, the catalytic effect of the ionic liquid (IL) on the cathode compared with that of a hydrochloric acid (HCl) solution with same pH value (0.8) is reported. A low activation energy (Ea) of 8.7 kJ mol-1 is found for the glassy carbon cathode. Tafel plots obtained with TEA-PS.BF4 IL suggest the formation of an electroactive layer of IL on the cathode, which may be responsible for the catalytically enhanced performance observed.

  4. Nucleophilic Addition of Nitrogen to Aryl Cations: Mimicking Titan Chemistry

    NASA Astrophysics Data System (ADS)

    Li, Anyin; Jjunju, Fred P. M.; Cooks, R. Graham

    2013-11-01

    The reactivity of aryl cations toward molecular nitrogen is studied systematically in an ion trap mass spectrometer at 102 Pascal of nitrogen, the pressure of the Titan main haze layer. Nucleophilic addition of dinitrogen occurs and the nature of aryl group has a significant influence on the reactivity, through inductive effects and by changing the ground state spin multiplicity. The products of nitrogen activation, aryldiazonium ions, react with typical nitriles, aromatic amines, and alkynes (compounds that are relevant as possible Titan atmosphere constituents) to form covalently bonded heterocyclic products. Theoretical calculations at the level [DFT(B3LYP)/6-311++G(d,p)] indicate that the N2 addition reaction is exothermic for the singlet aryl cations but endothermic for their triplet spin isomers. The -OH and -NH2 substituted aryl ions are calculated to have triplet ground states, which is consistent with their decreased nitrogen addition reactivity. The energy needed for the generation of the aryl cations from their protonated precursors (ca. 340 kJ/mol starting with protonated aniline) is far less than that required to directly activate the nitrogen triple bond (the lowest energy excited state of N2 lies ca. 600 kJ/mol above the ground state). The formation of aza-aromatics via arene ionization and subsequent reactions provide a conceivable route to the genesis of nitrogen-containing organic molecules in the interstellar medium and Titan haze layers.

  5. Nucleophilic addition of nitrogen to aryl cations: mimicking Titan chemistry.

    PubMed

    Li, Anyin; Jjunju, Fred P M; Cooks, R Graham

    2013-11-01

    The reactivity of aryl cations toward molecular nitrogen is studied systematically in an ion trap mass spectrometer at 10(2) Pascal of nitrogen, the pressure of the Titan main haze layer. Nucleophilic addition of dinitrogen occurs and the nature of aryl group has a significant influence on the reactivity, through inductive effects and by changing the ground state spin multiplicity. The products of nitrogen activation, aryldiazonium ions, react with typical nitriles, aromatic amines, and alkynes (compounds that are relevant as possible Titan atmosphere constituents) to form covalently bonded heterocyclic products. Theoretical calculations at the level [DFT(B3LYP)/6-311++G(d,p)] indicate that the N2 addition reaction is exothermic for the singlet aryl cations but endothermic for their triplet spin isomers. The -OH and -NH2 substituted aryl ions are calculated to have triplet ground states, which is consistent with their decreased nitrogen addition reactivity. The energy needed for the generation of the aryl cations from their protonated precursors (ca. 340 kJ/mol starting with protonated aniline) is far less than that required to directly activate the nitrogen triple bond (the lowest energy excited state of N2 lies ca. 600 kJ/mol above the ground state). The formation of aza-aromatics via arene ionization and subsequent reactions provide a conceivable route to the genesis of nitrogen-containing organic molecules in the interstellar medium and Titan haze layers. PMID:23982933

  6. Highly regioselective meta arylation of oxalyl amide-protected β-arylethylamine via the Catellani reaction.

    PubMed

    Han, Jian; Zhang, Li; Zhu, Yan; Zheng, Yongxiang; Chen, Xiaolan; Huang, Zhi-Bin; Shi, Da-Qing; Zhao, Yingsheng

    2016-05-25

    The first bidentate directing group assisted highly selective meta arylation of β-arylethylamine derivatives via palladium/norbornene catalysis is reported, and the range of aryl iodides for the oxalyl amide assisted meta-selective arylation reactions is broadest yet reported. This meta arylation also proceeds well with thiophene derivatives, giving the corresponding products in satisfactory yields. And three-step functionalization of arylethyloxalamide with three different functional groups is successfully performed. PMID:27142086

  7. Neuroendocrine effects of perfluorooctane sulfonate in rats.

    PubMed Central

    Austin, Maureen E; Kasturi, Badrinarayanan S; Barber, Matthew; Kannan, Kurunthachalam; MohanKumar, Puliyur S; MohanKumar, Sheba M J

    2003-01-01

    Perfluorooctane sulfonate (PFOS) is a degradation product of sulfonyl-based fluorochemicals that are used extensively in industrial and household applications. Humans and wildlife are exposed to this class of compounds from several sources. Toxicity tests in rodents have raised concerns about potential developmental, reproductive, and systemic effects of PFOS. However, the effect of PFOS on the neuroendocrine system has not been investigated thus far. In this study, adult female rats were injected intraperitoneally with 0, 1, or 10 mg PFOS/kg body weight (BW) for 2 weeks. Food and water intake, BW, and estrous cycles were monitored daily. At the end of treatment, PFOS levels in tissues were measured by high-performance liquid chromatography (HPLC) interfaced with electrospray mass spectrometry. Changes in brain monoamines were measured by HPLC with electrochemical detection, and serum corticosterone and leptin were monitored using radioimmunoassay. Treatment with PFOS produced a dose-dependent accumulation of this chemical in various body tissues, including the brain. PFOS exposure decreased food intake and BW in a dose-dependent manner. Treatment with PFOS affected estrous cyclicity and increased serum corticosterone levels while decreasing serum leptin concentrations. PFOS treatment also increased norepinephrine concentrations in the paraventricular nucleus of the hypothalamus. These results indicate that exposure to PFOS can affect the neuroendocrine system in rats. PMID:12948888

  8. Ion Exchange Formation via Sulfonated Bicomponent Nonwovens

    NASA Astrophysics Data System (ADS)

    Stoughton, Hannah L.

    For many years ion exchange resins were used to: remove heavy metals from water, recover materials from wastewater, and eliminate harmful gases from the air. While use of these resin beads dominates the ion exchange industry, the beads have limitations that should be considered when decisions are made to employ them. For instance, officials must balance the inherent zero sum surface area and porosity of the materials. This series of studies investigates the use of bicomponent nonwovens as a base substrate for producing high surface area ion exchange materials for the removal of heavy metal ions. Functionalized materials were produced in a two-step process: (1) PET/PE spunbond bicomponent fibers were fractured completely, producing the high surface area nonwoven to be used as the base ion exchange material, and (2) the conditions for functionalizing the PET fibers of the nonwoven webs were investigated where an epoxy containing monomer was grafted to the surface followed by sulfonation of the monomer. The functionalization reactions of the PET fibers were monitored based on: weight gain, FTIR, TOF-SIMS, and SEM. Ion exchange properties were evaluated using titration and copper ion removal capacity from test solutions. The relationship between web structure and removal efficiency of the metal ions was defined through a comparison of the bicomponent and homocomponent nonwovens for copper ion removal efficiency. The investigation revealed that utilizing the high surface area, fractured bicomponent nonwoven ion exchange materials with capacities comparable to commercially available ion exchange resins could be produced.

  9. Neuroendocrine effects of perfluorooctane sulfonate in rats.

    PubMed

    Austin, Maureen E; Kasturi, Badrinarayanan S; Barber, Matthew; Kannan, Kurunthachalam; MohanKumar, Puliyur S; MohanKumar, Sheba M J

    2003-09-01

    Perfluorooctane sulfonate (PFOS) is a degradation product of sulfonyl-based fluorochemicals that are used extensively in industrial and household applications. Humans and wildlife are exposed to this class of compounds from several sources. Toxicity tests in rodents have raised concerns about potential developmental, reproductive, and systemic effects of PFOS. However, the effect of PFOS on the neuroendocrine system has not been investigated thus far. In this study, adult female rats were injected intraperitoneally with 0, 1, or 10 mg PFOS/kg body weight (BW) for 2 weeks. Food and water intake, BW, and estrous cycles were monitored daily. At the end of treatment, PFOS levels in tissues were measured by high-performance liquid chromatography (HPLC) interfaced with electrospray mass spectrometry. Changes in brain monoamines were measured by HPLC with electrochemical detection, and serum corticosterone and leptin were monitored using radioimmunoassay. Treatment with PFOS produced a dose-dependent accumulation of this chemical in various body tissues, including the brain. PFOS exposure decreased food intake and BW in a dose-dependent manner. Treatment with PFOS affected estrous cyclicity and increased serum corticosterone levels while decreasing serum leptin concentrations. PFOS treatment also increased norepinephrine concentrations in the paraventricular nucleus of the hypothalamus. These results indicate that exposure to PFOS can affect the neuroendocrine system in rats. PMID:12948888

  10. Ultra-bright alkylated graphene quantum dots

    NASA Astrophysics Data System (ADS)

    Feng, Lan; Tang, Xing-Yan; Zhong, Yun-Xin; Liu, Yue-Wen; Song, Xue-Huan; Deng, Shun-Liu; Xie, Su-Yuan; Yan, Jia-Wei; Zheng, Lan-Sun

    2014-10-01

    Highly efficient and stable photoluminescence (PL) are urgently desired for graphene quantum dots (GQDs) to facilitate their prospective applications as optical materials. Here, we report the facile and straightforward synthesis of alkylated graphene quantum dots (AGQDs) via the solvothermal reaction of propagatively alkylated graphene sheets (PAGenes). In contrast to most GQDs reported so far, the synthesized AGQDs process pH-independent and ultra-bright PL with a relative quantum yield of up to 65%. Structural and chemical composition characterization demonstrated that the synthesized AGQDs are nearly oxygen-defect-free with alkyl groups decorated on edges and basal plane, which may contribute to their greatly improved pH tolerance and high quantum efficiency. The photocatalytic performance of AGQDs-P25 nanocomposites was evaluated by the degradation of Rhodamine B under visible light. The photocatalytic rate is ca. 5.9 times higher than that of pure P25, indicating that AGQDs could harness the visible spectrum of sunlight for energy conversion or environmental therapy.Highly efficient and stable photoluminescence (PL) are urgently desired for graphene quantum dots (GQDs) to facilitate their prospective applications as optical materials. Here, we report the facile and straightforward synthesis of alkylated graphene quantum dots (AGQDs) via the solvothermal reaction of propagatively alkylated graphene sheets (PAGenes). In contrast to most GQDs reported so far, the synthesized AGQDs process pH-independent and ultra-bright PL with a relative quantum yield of up to 65%. Structural and chemical composition characterization demonstrated that the synthesized AGQDs are nearly oxygen-defect-free with alkyl groups decorated on edges and basal plane, which may contribute to their greatly improved pH tolerance and high quantum efficiency. The photocatalytic performance of AGQDs-P25 nanocomposites was evaluated by the degradation of Rhodamine B under visible light. The

  11. Aryl Rhodanines Specifically Inhibit Staphylococcal and Enterococcal Biofilm Formation▿ †

    PubMed Central

    Opperman, Timothy J.; Kwasny, Steven M.; Williams, John D.; Khan, Atiyya R.; Peet, Norton P.; Moir, Donald T.; Bowlin, Terry L.

    2009-01-01

    Staphylococcus epidermidis and Staphylococcus aureus are the leading causative agents of indwelling medical device infections because of their ability to form biofilms on artificial surfaces. Here we describe the antibiofilm activity of a class of small molecules, the aryl rhodanines, which specifically inhibit biofilm formation of S. aureus, S. epidermidis, Enterococcus faecalis, E. faecium, and E. gallinarum but not the gram-negative species Pseudomonas aeruginosa or Escherichia coli. The aryl rhodanines do not exhibit antibacterial activity against any of the bacterial strains tested and are not cytotoxic against HeLa cells. Preliminary mechanism-of-action studies revealed that the aryl rhodanines specifically inhibit the early stages of biofilm development by preventing attachment of the bacteria to surfaces. PMID:19651903

  12. Poly(arylene ether sulfone)s ionomers containing quaternized triptycene groups for alkaline fuel cell

    NASA Astrophysics Data System (ADS)

    Zhao, Zhuo; Gong, Feixiang; Zhang, Suobo; Li, Shenghai

    2012-11-01

    A series of poly(arylene ether sulfone)s containing quaternized triptycene groups are synthesized through a chloromethylation reaction following a quaternization process. The resulting ionomers are soluble in polar aprotic solvents; thus, flexible, tough membranes could be prepared by solution casting. Novel anion exchange membranes based on these ionomers are obtained by anion exchange with hydroxide ions. All anion exchange membranes show conductivities above 10-2 S cm-1 at room temperature. The highest hydroxide conductivity is 7.2 × 10-2 S cm-1, which is achieved by the anion exchange membrane with ion exchange capacity (IEC) = 2.61 mmol g-1. Meanwhile, these anion exchange membranes have low water uptake and good dimensional stability even at high IEC values. For example, the membrane water uptake (IEC = 1.97 mmol g-1) is only 21% at room temperature, and the swelling ratio is 11%. The anion exchange membranes are stable in alkaline conditions. All the membranes have no significant change in 4 M NaOH solution at 25 °C after 30 days. All results suggest that these anion exchange membranes have potential application in alkaline fuel cells.

  13. PROCESS FOR PRODUCING ALKYL ORTHOPHOSPHORIC ACID EXTRACTANTS

    DOEpatents

    Grinstead, R.R.

    1962-01-23

    A process is given for producing superior alkyl orthophosphoric acid extractants for use in solvent extraction methods to recover and purify various metals such as uranium and vanadium. The process comprises slurrying P/sub 2/O/ sub 5/ in a solvent diluent such as kerosene, benzene, isopropyl ether, and the like. An alipbatic alcohol having from nine to seventeen carbon atoms, and w- hcrein ihc OH group is situated inward of the terminal carbon atoms, is added to the slurry while the reaction temperature is mainiained below 60 deg C. The alcohol is added in the mole ratio of about 2 to l, alcohol to P/sub 2/O/sub 5/. A pyrophosphate reaotion product is formed in the slurry-alcohol mixture. Subsequently, the pyrophosphate reaction product is hydrolyzed with dilute mineral acid to produce the desired alkyl orthophosphoric aeid extractant. The extraetant may then be separated and utilized in metal-recovery, solvent- extraction processes. (AEC)

  14. ALKYL PYROPHOSPHATE METAL SOLVENT EXTRACTANTS AND PROCESS

    DOEpatents

    Long, R.L.

    1958-09-30

    A process is presented for the recovery of uranium from aqueous mineral acidic solutions by solvent extraction. The extractant is a synmmetrical dialkyl pyrophosphate in which the alkyl substituents have a chain length of from 4 to 17 carbon atoms. Mentioned as a preferred extractant is dioctyl pyrophosphate. The uranium is precipitated irom the organic extractant phase with an agent such as HF, fluoride salts. alcohol, or ammonia.

  15. In pursuit of homoleptic actinide alkyl complexes.

    PubMed

    Seaman, Lani A; Walensky, Justin R; Wu, Guang; Hayton, Trevor W

    2013-04-01

    This Forum Article describes the pursuit of isolable homoleptic actinide alkyl complexes, starting with the pioneering work of Gilman during the Manhattan project. The initial reports in this area suggested that homoleptic uranium alkyls were too unstable to be isolated, but Wilkinson demonstrated that tractable uranium alkyls could be generated by purposeful "ate" complex formation, which serves to saturate the uranium coordination sphere and provide the complexes with greater kinetic stability. More recently, we reported the solid-state molecular structures of several homoleptic uranium alkyl complexes, including [Li(THF)4][U(CH2(t)Bu)5], [Li(TMEDA)]2[UMe6], [K(THF)]3[K(THF)2][U(CH2Ph)6]2, and [Li(THF)4][U(CH2SiMe3)6], by employing Wilkinson's strategy. Herein, we describe our attempts to extend this chemistry to thorium. The treatment of ThCl4(DME)2 with 5 equiv of LiCH2(t)Bu or LiCH2SiMe3 at -25 °C in THF affords [Th(CH2(t)Bu)5] (1) and [Li(DME)2][Th(CH2SiMe3)5 (2), respectively, in moderate yields. Similarly, the treatment of ThCl4(DME)2 with 6 equiv of K(CH2Ph) produces [K(THF)]2[Th(CH2Ph)6] (3), in good yield. Complexes 1-3 have been fully characterized, while the structures of 1 and 3 were confirmed by X-ray crystallography. Additionally, the electronic properties of 1 and 3 were explored by density functional theory. PMID:22716022

  16. Selective Metal-Site-Guided Arylation of Proteins.

    PubMed

    Willwacher, Jens; Raj, Ritu; Mohammed, Shabaz; Davis, Benjamin G

    2016-07-20

    We describe palladium-mediated S-arylation that exploits natural metal-binding motifs to ensure high site selectivity for a proximal reactive residue. This allows the chemical identification not only of proteins that bind metals but also the environment of the metal-binding site itself through proteomic analysis of arylation sites. The transformation is easy to perform under standard conditions, does not require the isolation of a reactive Ar-Pd complex, is broad in scope, and is applicable in cell lysates as well as to covalent inhibition/modulation of metal-dependent enzymatic activity. PMID:27336299

  17. NITROSATION OF ARYL AND HETEROARYLTRIFLUOROBORATES WITH NITROSONIUM TETRAFLUOROBORATE

    PubMed Central

    Cavalcanti, Livia N.

    2012-01-01

    Organotrifluoroborates have emerged as an alternative to toxic and air- and moisture sensitive organometallic species for the synthesis of functionalized aryl and heteroaryl compounds. It has been shown that the trifluoroborate moiety can be easily converted into a variety of different substituents in a late synthetic stage. In this paper we disclose a mild, selective, and convenient method for the ipso-nitrosation of organotrifluoroborates using nitrosonium tetrafluoroborate (NOBF4). Aryl- and heteroaryltrifluoroborates were converted into the corresponding nitroso products in good to excellent yields. This method proved to be tolerant of a broad range of functional groups. PMID:22524190

  18. Ultra-bright alkylated graphene quantum dots.

    PubMed

    Feng, Lan; Tang, Xing-Yan; Zhong, Yun-Xin; Liu, Yue-Wen; Song, Xue-Huan; Deng, Shun-Liu; Xie, Su-Yuan; Yan, Jia-Wei; Zheng, Lan-Sun

    2014-11-01

    Highly efficient and stable photoluminescence (PL) are urgently desired for graphene quantum dots (GQDs) to facilitate their prospective applications as optical materials. Here, we report the facile and straightforward synthesis of alkylated graphene quantum dots (AGQDs) via the solvothermal reaction of propagatively alkylated graphene sheets (PAGenes). In contrast to most GQDs reported so far, the synthesized AGQDs process pH-independent and ultra-bright PL with a relative quantum yield of up to 65%. Structural and chemical composition characterization demonstrated that the synthesized AGQDs are nearly oxygen-defect-free with alkyl groups decorated on edges and basal plane, which may contribute to their greatly improved pH tolerance and high quantum efficiency. The photocatalytic performance of AGQDs-P25 nanocomposites was evaluated by the degradation of Rhodamine B under visible light. The photocatalytic rate is ca. 5.9 times higher than that of pure P25, indicating that AGQDs could harness the visible spectrum of sunlight for energy conversion or environmental therapy. PMID:25192187

  19. Ruthenium-catalyzed alkylation of indoles with tertiary amines by oxidation of a sp3 C-H bond and Lewis acid catalysis.

    PubMed

    Wang, Ming-Zhong; Zhou, Cong-Ying; Wong, Man-Kin; Che, Chi-Ming

    2010-05-17

    Ruthenium porphyrins (particularly [Ru(2,6-Cl(2)tpp)CO]; tpp=tetraphenylporphinato) and RuCl(3) can act as oxidation and/or Lewis acid catalysts for direct C-3 alkylation of indoles, giving the desired products in high yields (up to 82% based on 60-95% substrate conversions). These ruthenium compounds catalyze oxidative coupling reactions of a wide variety of anilines and indoles bearing electron-withdrawing or electron-donating substituents with high regioselectivity when using tBuOOH as an oxidant, resulting in the alkylation of N-arylindoles to 3-{[(N-aryl-N-alkyl)amino]methyl}indoles (yield: up to 82%, conversion: up to 95%) and the alkylation of N-alkyl or N-H indoles to 3-[p-(dialkylamino)benzyl]indoles (yield: up to 73%, conversion: up to 92%). A tentative reaction mechanism involving two pathways is proposed: an iminium ion intermediate may be generated by oxidation of an sp(3) C-H bond of the alkylated aniline by an oxoruthenium species; this iminium ion could then either be trapped by an N-arylindole (pathway A) or converted to formaldehyde, allowing a subsequent three-component coupling reaction of the in situ generated formaldehyde with an N-alkylindole and an aniline in the presence of a Lewis acid catalyst (pathway B). The results of deuterium-labeling experiments are consistent with the alkylation of N-alkylindoles via pathway B. The relative reaction rates of [Ru(2,6-Cl(2)tpp)CO]-catalyzed oxidative coupling reactions of 4-X-substituted N,N-dimethylanilines with N-phenylindole (using tBuOOH as oxidant), determined through competition experiments, correlate linearly with the substituent constants sigma (R(2)=0.989), giving a rho value of -1.09. This rho value and the magnitudes of the intra- and intermolecular deuterium isotope effects (k(H)/k(D)) suggest that electron transfer most likely occurs during the initial stage of the oxidation of 4-X-substituted N,N-dimethylanilines. Ruthenium-catalyzed three-component reaction of N-alkyl/N-H indoles

  20. Formation of ArF from LPdAr(F): catalytic conversion of aryl triflates to aryl fluorides.

    PubMed

    Watson, Donald A; Su, Mingjuan; Teverovskiy, Georgiy; Zhang, Yong; García-Fortanet, Jorge; Kinzel, Tom; Buchwald, Stephen L

    2009-09-25

    Despite increasing pharmaceutical importance, fluorinated aromatic organic molecules remain difficult to synthesize. Present methods require either harsh reaction conditions or highly specialized reagents, making the preparation of complex fluoroarenes challenging. Thus, the development of general methods for their preparation that overcome the limitations of those techniques currently in use is of great interest. We have prepared [LPd(II)Ar(F)] complexes, where L is a biaryl monophosphine ligand and Ar is an aryl group, and identified conditions under which reductive elimination occurs to form an Ar-F bond. On the basis of these results, we have developed a catalytic process that converts aryl bromides and aryl triflates into the corresponding fluorinated arenes by using simple fluoride salts. We expect this method to allow the introduction of fluorine atoms into advanced, highly functionalized intermediates. PMID:19679769

  1. (R)-[1-(2-Chloro­phen­yl)-2-meth­oxy-2-oxoeth­yl][2-(thio­phen-2-yl)eth­yl]ammonium (+)-camphor-10-sulfonate acetone monosolvate

    PubMed Central

    Liang, Yan-Shu; Mu, Shuai; Liu, Ying; Liu, Deng-Ke

    2010-01-01

    The title compound, C15H17ClNO2S+·C10H15O4S−·C3H6O, was synthesized by N-alkyl­ation of α-amino-(2-chloro­phen­yl)acetate with 2-thienylethyl p-toluene­sulfonate, followed by reaction with (+)-camphor-10-sulfonic acid. In the crystal, the cations and anions are linked through N—H⋯O hydrogen bonds. The thio­phene ring of the cation was found to be disordered over two sites, with refined occupancies of 0.798 (4) and 0.202 (4). PMID:21589421

  2. Transition-metal-free, ambient-pressure carbonylative cross-coupling reactions of aryl halides with potassium aryltrifluoroborates.

    PubMed

    Jin, Fengli; Han, Wei

    2015-06-01

    We disclose an unprecedented transition-metal-free carbonylative cross coupling of aryl halides with potassium aryl trifluoroborates even at atmospheric pressure of carbon monoxide. This protocol is efficient, operationally simple, and shows wide scope with regard to both aryl halides and potassium aryl trifluoroborates containing a series of active functional groups. PMID:25939449

  3. NH-Heterocyclic Aryliodonium Salts and their Selective Conversion into N1-Aryl-5-iodoimidazoles.

    PubMed

    Wu, Yichen; Izquierdo, Susana; Vidossich, Pietro; Lledós, Agustí; Shafir, Alexandr

    2016-06-13

    The synthesis of N-arylimidazoles substituted at the sterically encumbered 5-position is a challenge for modern synthetic approaches. A new family of imidazolyl aryliodonium salts is reported, which serve as a stepping stone on the way to selective formation of N1-aryl-5-iodoimidazoles. Iodine acts as a "universal" placeholder poised for replacement by aryl substituents. These new λ(3) -iodanes are produced by treating the NH-imidazole with ArI(OAc)2 , and are converted to N1-aryl-5-iodoimidazoles by a selective copper-catalyzed aryl migration. The method tolerates a variety of aryl fragments and is also applicable to substituted imidazoles. PMID:27142566

  4. Studies of the condensation of sulfones with ketones and aldehydes.

    PubMed

    Garst, Michael E; Dolby, Lloyd J; Esfandiari, Shervin; Okrent, Rachel A; Avey, Alfred A

    2006-01-20

    [reaction: see text] The condensation of ketones or aldehydes with sulfones was shown to give a variety of products. Condensation of 2-methylcyclohexanone with dimethyl sulfone using potassium t-butoxide as base gave useful yields of 1,2-dimethylenecyclohexane. Under the same conditions, cycloheptanone, 3-methyl-2-butanone, and 2-butanone were converted to dienes. Remarkably, these reaction conditions converted acetophenone into p-terphenyl (10%) and (E)-1,4-diphenyl-3-penten-1-one (44%). Propiophenone was converted to 2'-methyl-p-terphenyl (61%). Using alpha-tetralone produced 1-methynaphthalene and naphthalene. No reaction took place with beta-tetralone. Using diethyl sulfone with alpha-tetralone lead to pure naphthalene. Condensation of isobutyraldehyde and dimethyl sulfone using potassium t-butoxide gave isoprene in low yield. Using benzaldehyde and benzyl phenyl sulfone in N,N-dimethylacetamide gave 1,2-diphenyl-1-phenylsulfonylethylene, N,N-dimethylcinnamide, and a complex condensation product. Only 1,2-diphenyl-1-phenylsulfonylethylene was obtained when the solvent was THF. PMID:16408963

  5. A general and efficient approach to aryl thiols: CuI-catalyzed coupling of aryl iodides with sulfur and subsequent reduction.

    PubMed

    Jiang, Yongwen; Qin, Yuxia; Xie, Siwei; Zhang, Xiaojing; Dong, Jinhua; Ma, Dawei

    2009-11-19

    A CuI-catalyzed coupling reaction of aryl iodides and sulfur powder takes place in the presence of K(2)CO(3) at 90 degrees C. The coupling mixture is directly treated with NaBH(4) or triphenylphosphine to afford aryl thiols in good to excellent yields. A wide range of substituted aryl thiols that bear methoxy, hydroxyl, carboxylate, amido, keto, bromo, and fluoro groups can be assembled through this procedure. PMID:19835369

  6. CuO-promoted construction of N-2-aryl-substituted-1,2,3-triazoles via azide-chalcone oxidative cycloaddition and post-triazole arylation.

    PubMed

    Zhang, Yuanqing; Li, Xiaolong; Li, Jihui; Chen, Jinying; Meng, Xu; Zhao, Mingming; Chen, Baohua

    2012-01-01

    An efficient one-pot three-component stepwise approach for the synthesis of N-2-aryl-substituted-1,2,3-triazoles has been developed. By using this azide-chalcone oxidative cycloaddition and post-triazole arylation, a series of N-2-aryl-substituted-1,2,3-triazoles are readily prepared under mild conditions in excellent yields and high regioselectivity. Both the catalyst and substrates are readily available. PMID:22133007

  7. Synthesis of Dibenzosultams by "Transition-Metal-Free" Photoinduced Intramolecular Arylation of N-Aryl-2-halobenzenesulfonamides.

    PubMed

    Guerra, Walter D; Rossi, Roberto A; Pierini, Adriana B; Barolo, Silvia M

    2016-06-17

    A new and general synthetic route to prepare dibenzosultams is here reported. This approach involves the synthesis of N-aryl-2-halobenzenesulfonamides (3), followed by intramolecular C-C photoinduced arylation under soft conditions without the use of "Transition Metal". The photostimulated reactions exhibit very good tolerance to different substituent groups with good to excellent isolated yields (42-98%) of products. Moreover, it is shown that LED (λ = 395 nm) is an efficient light energy source to initiate efficiently the reactions. Theoretical inspection of the mechanism was made to probe the involvement of the radical-anion SRN1 process. PMID:27166973

  8. New Trends in Aryl Hydrocarbon Receptor Biology

    PubMed Central

    Mulero-Navarro, Sonia; Fernandez-Salguero, Pedro M.

    2016-01-01

    Traditionally considered as a critical intermediate in the toxic and carcinogenic response to dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD), the Aryl hydrocarbon/Dioxin receptor (AhR) has proven to be also an important regulator of cell physiology and organ homeostasis. AhR has become an interesting and actual area of research mainly boosted by a significant number of recent studies analyzing its contribution to the proper functioning of the immune, hepatic, cardiovascular, vascular and reproductive systems. At the cellular level, AhR establishes functional interactions with signaling pathways governing cell proliferation and cell cycle, cell morphology, cell adhesion and cell migration. Two exciting new aspects in AhR biology deal with its implication in the control of cell differentiation and its more than likely involvement in cell pluripotency and stemness. In fact, it is possible that AhR could help modulate the balance between differentiation and pluripotency in normal and transformed tumor cells. At the molecular level, AhR regulates an increasingly large array of physiologically relevant genes either by traditional transcription-dependent mechanisms or by unforeseen processes involving genomic insulators, chromatin dynamics and the transcription of mobile genetic elements. AhR is also closely related to epigenetics, not only from the point of view of target gene expression but also with respect to its own regulation by promoter methylation. It is reasonable to consider that deregulation of these many functions could have a causative role, or at least contribute to, human disease. Consequently, several laboratories have proposed that AhR could be a valuable tool as diagnostic marker and/or therapeutic target in human pathologies. An additional point of interest is the possibility of regulating AhR activity by endogenous non-toxic low weight molecules agonist or antagonist molecules that could be present or included in the diet. In this review, we will

  9. Synthesis and characterization of sulfonated poly (arylene ether sulfone) copolymers via direct copolymerization: Candidates for proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Harrison, William Lamont

    A designed series of directly copolymerized homo- and disulfonated copolymers containing controlled degrees of pendant sulfonic acid groups have been synthesized via nucleophilic step polymerization. Novel sulfonated poly (arylene ether sulfone) copolymers using 4,4'-bisphenol A, 4,4'-biphenol, hexafluorinated (6F) bisphenol AF, and hydroquinone, respectively, with dichlorodiphenyl sulfone (DCDPS) and 3,3'-disodiumsulfonyl-4,4'-dichlorodiphenylsulfone (SDCDPS) were investigated. Molar ratios of DCDPS and SDCDPS were systematically varied to produce copolymers of controlled compositions, which contained up to 70 mol% of disulfonic acid moiety. The goal is to identify thermally, hydrolytically, and oxidatively stable high molecular weight, film-forming, ductile ion conducting copolymers, which had properties desirable for proton exchange membranes (PEM) in fuel cells. Commercially available bisphenols were selected to produce cost effective alternative PEMs. Partially aliphatic bisphenol A and hexafluorinated (6F) bisphenol AF produced amorphous copolymers with different thermal oxidative and surface properties. Biphenol and hydroquinone was utilized to produce wholly aromatic copolymers. The sulfonated copolymers were prepared in the sodium-salt form and converted to the acid moiety via two different methodologies and subsequently investigated as proton exchange membranes for fuel cells. Hydrophilicity increased with the level of disulfonation, as expected. Moreover, water sorption increased with increasing mole percent incorporation of SDCDPS. The copolymers' water uptake was a function of both bisphenol structure and degree of disulfonation. Furthermore, the acidification procedures were shown to influence the Tg values, water uptake, and conductivity of the copolymers. Atomic force microscopy (AFM) in the tapping mode confirmed that the morphology of the copolymers could be designed to display nanophase separation in the hydrophobic and hydrophilic (sulfonated

  10. Iron(III) Chloride Catalyzed Formation of 3,4-Dihydro-2H-pyrans from α-Alkylated 1,3-Dicarbonyls. Selective Synthesis of α- and β-Lapachone.

    PubMed

    Watson, Rebecca B; Golonka, Alexander N; Schindler, Corinna S

    2016-03-18

    A mild, catalytic method for the synthesis of 3,4-dihydro-2H-pyrans is described. The FeCl3-catalyzed transformation of aryl- and alkyl β-diketones enables synthetic access to functionalized pyran core structures incorporated in many natural products and biologically active target structures. The method represents a mild alternative to currently available reaction protocols relying on stoichiometric reagents and harsh reaction conditions. This FeCl3-catalyzed transformation has enabled the selective synthesis of α-lapachone in two synthetic transformations and subsequently β-lapachone in three synthetic transformations, which is currently undergoing clinical trials as a potent anticancer agent. PMID:26934747

  11. Sulfonation Pathway Inhibitors Block Reactivation of Latent HIV-1

    PubMed Central

    Murry, Jeffrey P.; Godoy, Joseph; Mukim, Amey; Swann, Justine; Bruce, James W.; Ahlquist, Paul; Bosque, Alberto; Planelles, Vicente; Spina, Celsa A.; Young, John A. T.

    2015-01-01

    Long-lived pools of latently infected cells are a significant barrier to the development of a cure for HIV-1 infection. A better understanding of the mechanisms of reactivation from latency is needed to facilitate the development of novel therapies that address this problem. Here we show that chemical inhibitors of the sulfonation pathway prevent virus reactivation, both in latently infected J-Lat and U1 cell lines and in a primary human CD4+ T cell model of latency. In each of these models, sulfonation inhibitors decreased transcription initiation from the HIV-1 promoter. These inhibitors block transcription initiation at a step that lies downstream of nucleosome remodeling and affects RNA polymerase II recruitment to the viral promoter. These results suggest that the sulfonation pathway acts by a novel mechanism to regulate efficient virus transcription initiation during reactivation from latency, and further that augmentation of this pathway could be therapeutically useful. PMID:25310595

  12. Characterization of sulfonated silica nanocomposite electrolyte membranes for fuel cell.

    PubMed

    Kim, Deuk-Ju; Nam, Sang-Yong

    2014-12-01

    Sulfonated poly(arylene ether sulfone) (SPAES) and sulfonated silica (silica-SO3H) prepared via sol-gel reaction are used as an organic polymer matrix and inorganic nanoparticles. The contents of the silica-SO3H particles in the composite membranes are controlled at 0.5, 1, 2, 3 and 5 wt.% in order to evaluate the appropriate content for high proton conductivity. Randomly dispersed silica particles are obtained from all composite membranes as a result of the hydrophilic domains in the polymer and silica-SO3H. In this study, the optimum silica-SO3H content for high proton conductivity is 3 wt.% in fully hydrated conditions and 0.5 wt.% in low humidity conditions. PMID:25970990

  13. Palladium-catalyzed arylation of simple arenes with iodonium salts.

    PubMed

    Storr, Thomas E; Greaney, Michael F

    2013-03-15

    The development of an arylation protocol for simple arenes with diaryliodonium salts using the Herrmann-Beller palladacycle catalyst is reported. The reaction takes simple aromatic feedstocks and creates valuable biaryls for use in all sectors of the chemical industry. PMID:23461706

  14. Palladium-Catalyzed α-Arylation of Benzylic Phosphonates

    PubMed Central

    2015-01-01

    A new synthetic route to access diarylmethyl phosphonates is presented. The transformation enables the introduction of aromatic groups on benzylic phosphonates via a deprotonative cross-coupling process (DCCP). The Pd(OAc)2/CataCXium A-based catalyst afforded a reaction between benzyl diisopropyl phosphonate derivatives and aryl bromides in good to excellent isolated yields (64–92%). PMID:24520897

  15. Lithium perchlorate-nitromethane-promoted alkylation of anilines with arylmethanols.

    PubMed

    Zhou, Jun; Mao, Hai-Feng; Wang, Lu; Zou, Jian-Ping; Zhang, Wei

    2011-11-01

    A new application of lithium perchlorate-nitromethane (LPNM) for the formation of aromatic C-N and C-C bonds is introduced. LPNM-promoted reactions of anilines with diarylmethanols selectively generate N-alkylated anilines or mono and double Friedel-Crafts alkylation products under different conditions by changing the reaction time, reaction temperature, and the ratio of the reactants. This method does not require the use of transition metal catalysts to prepare alkylated aniline derivatives. PMID:21547437

  16. Neutral and Cationic Alkyl Tantalum Imido Complexes: Synthesis and Migratory Insertion Reactions

    PubMed Central

    Anderson, Laura L.; Schmidt, Joseph A. R.; Arnold, John; Bergman, Robert G.

    2008-01-01

    The synthesis and reactivity of dibenzyl cationic tantalum imido complexes is described. The trialkyl tantalum imido compounds Bn3Ta=NCMe3 (1) and Np3Ta=NCMe3 (2) were synthesized as starting materials for the study of dialkyl cationic tantalum imido complexes. Compound 1 undergoes insertion reactions with diisopropylcarbodiimide and 2,6-dimethylphenylisocyanide to give (bisamidinate)imido complex 5 and (bisimino-acyl)imido complex 6, respectively. Treatment of compound 1 with B(C6F5)3 gives the zwitterionic tantalum complex [Bn2Ta=NCMe3][BnB(C6F5)3] (7) which is stabilized by η6-coordination of the benzyl triaryl borate anion. Coordination of the aryl anion can be displaced by three equivalents of pyridine to give the Lewis base complex 8. Treatment of compound 1 with [Ph3C][B(C6F5)4] gives the cationic tantalum imido complex [Bn2Ta=NCMe3][B(C6F5)4] (3). This salt forms insoluble aggregates unless trapped by THF coordination or an insertion reaction with an alkyne or an alkene. Cation 3 undergoes migratory insertion reactions with diphenylacetylene, phenylacetylene, norbornene, and cis-cyclooctene to give the corresponding alkenyl or modified alkyl imido complexes. The characterization of these products and the significance of these insertion reactions with respect to Ziegler-Natta polymerizations and hydroamination reactions are described. PMID:19079787

  17. Sulfur and Hydrogen Isotope Anomalies in Meteorite Sulfonic Acids

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Thiemens, Mark H.; Jackson, Teresa L.; Chang, Sherwood

    1997-01-01

    Intramolecular carbon, hydrogen, and sulfur isotope ratios were measured on a homologous series of organic sulfonic acids discovered in the Murchison meteorite. Mass-independent sulfur isotope fractionations were observed along with high deuterium/hydrogen ratios. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low-temperature environment that is consistent with that of interstellar clouds. Sulfur-33 enrichments observed in methanesulfonic acid could have resulted from gas-phase ultraviolet irradiation of a precursor, carbon disulfide. The source of the sulfonic acid precursors may have been the reactive interstellar molecule carbon monosulfide.

  18. A Phase I Study of DMS612, a Novel Bi-functional Alkylating Agent

    PubMed Central

    Appleman, Leonard J.; Balasubramaniam, Sanjeeve; Parise, Robert A; Bryla, Christine; Redon, Christophe E.; Nakamura, Asako J.; Bonner, William M.; Wright, John J; Piekarz, Richard; Kohler, David R; Jiang, Yixing; Belani, Chandra P.; Eiseman, Julie; Chu, Edward; Beumer, Jan H.; Bates, Susan E.

    2016-01-01

    Purpose DMS612 is a dimethane sulfonate analog with bifunctional alkylating activity and preferential cytotoxicity to human renal cell carcinoma (RCC) in the NCI-60 cell panel. This first-in-human phase I study aimed to determine dose-limiting toxicity (DLT), maximum tolerated dose (MTD), pharmacokinetics (PK), and pharmacodynamics (PD) of DMS612 administered by 10-min intravenous infusion on days 1, 8, and 15 of an every 28-day schedule. Experimental Design Patients with advanced solid malignancies were eligible. Enrollment followed a 3+3 design. Pharmacokinetics of DMS612 and metabolites were assessed by mass spectroscopy and pharmacodynamics by γ-H2AX immunofluorescence. Results A total of 31 patients with colorectal (11), RCC (4), cervical (2), and urothelial (1) cancers were enrolled. Six dose levels were studied, from 1.5 mg/m2 to 12 mg/m2. DLTs of grade 4 neutropenia and prolonged grade 3 thrombocytopenia were observed at 12 mg/m2. The MTD was determined to be 9 mg/m2 with a single DLT of grade 4 thrombocytopenia in 1 of 12 patients. Two patients had a confirmed partial response at the 9 mg/m2 dose level, in renal (1) and cervical (1) cancer. DMS612 was rapidly converted into active metabolites. γ-H2AX immunofluorescence revealed dose-dependent DNA damage in both peripheral blood lymphocytes and scalp hairs. Conclusions The MTD of DMS12 on days 1, 8, and 15 every 28 days was 9 mg/m2. DMS612 appears to be an alkylating agent with unique tissue specificities. Dose-dependent pharmacodynamic signals and 2 partial responses at the MTD support further evaluation of DMS612 in phase II trials. PMID:25467180

  19. Aminooxylation Horner-Wadsworth-Emmons Sequence for the Synthesis of Enantioenriched γ-Functionalized Vinyl Sulfones.

    PubMed

    Doherty, William; Evans, Paul

    2016-02-19

    An operationally simple protocol for the synthesis of γ-hydroxy vinyl sulfones has been developed using a proline-based aldehyde aminooxylation, followed by a vinyl sulfone forming Horner-Wadsworth-Emmons olefination. The adducts, formed in high enantiopurity, were subsequently converted to γ-azido vinyl sulfones, and azide-alkyne click chemistry enabled the synthesis of vinyl sulfone-based triazoles as potential nonpeptidic cysteine protease inhibitors. PMID:26818590

  20. Exisulind: Aptosyn, FGN 1, Prevatac, sulindac sulfone.

    PubMed

    2004-01-01

    Exisulind [Aptosyn trade mark, FGN 1 trade mark, Prevatac trade mark, sulindac sulfone], the sulfone derivative of sulindac, is the lead compound in a series of selective apoptotic antineoplastic drugs (SAANDs) being developed by OSI Pharmaceuticals. The compounds were originally developed by Cell Pathways, which was acquired by, and integrated into, OSI Pharmaceuticals in June 2003. Exisulind inhibits the enzyme cyclic GMP phosphodiesterase (GMP-PDE), overexpressed in precancerous and cancerous colorectal cells, and induces apoptosis in such cells with minimal effects on normal cells. This apoptotic effect is independent of COX I or COX II inhibition, p53, Bcl-2, or cell-cycle arrest. Preclinical evidence suggests that exisulind also inhibits angiogenesis. Cell Pathways has formed sales and distribution agreements with three healthcare-related companies in the US for its future marketing and support campaign for exisulind. Innovex will hire and train sales representatives for Cell Pathways to launch and promote exisulind, Livingston Healthcare Services will be responsible for customer service, order and distribution administration, and Lash Group will be responsible for the development and implementation of reimbursement support services for exisulind. Cell Pathways has issued an exclusive licence for exisulind to Paladin Labs of Montreal, Canada. The agreement allows Paladin exclusive rights to commercialise the drug in Canada. In August 1999 Cell Pathways submitted an NDA application to the US FDA for exisulind (Aptosyn) for the treatment of familial adenomatous polyposis (FAP). However, in September 2000, the FDA announced that it had found deficiencies in the safety and efficacy data of Cell Pathways' NDA, and returned a non-approvable letter to the company. Cell Pathways then initiated another phase III study of the agent in combination with Aventis' docetaxel and comparing combination therapy with docetaxel alone. Exisulind has fast-track designation for FAP

  1. Biaryl and aryl ketone synthesis via Pd-catalyzed decarboxylative coupling of carboxylate salts with aryl triflates.

    PubMed

    Goossen, Lukas J; Linder, Christophe; Rodríguez, Nuria; Lange, Paul P

    2009-09-21

    A bimetallic catalyst system has been developed that for the first time allows the decarboxylative cross-coupling of aryl and acyl carboxylates with aryl triflates. In contrast to aryl halides, these electrophiles give rise to non-coordinating anions as byproducts, which do not interfere with the decarboxylation step that leads to the generation of the carbon nucleophilic cross-coupling partner. As a result, the scope of carboxylate substrates usable in this transformation was extended from ortho-substituted or otherwise activated derivatives to a broad range of ortho-, meta-, and para-substituted aromatic carboxylates. Two alternative protocols have been optimized, one involving heating the substrates in the presence of Cu(I)/1,10-phenanthroline (10-15 mol %) and PdI(2)/phosphine (2-3 mol %) in NMP for 1-24 h, the other involving Cu(I)/1,10-phenanthroline (6-15 mol %) and PdBr(2)/Tol-BINAP (2 mol %) in NMP using microwave heating for 5-10 min. While most products are accessible using standard heating, the use of microwave irradiation was found to be beneficial especially for the conversion of non-activated carboxylates with functionalized aryl triflates. The synthetic utility of the transformation is demonstrated with 48 examples showing the scope and limitations of both protocols. In mechanistic studies, the special role of microwave irradiation is elucidated, and further perspectives of decarboxylative cross-couplings are discussed. PMID:19718720

  2. Alkyl Chlorides as Hydrogen Bond Acceptors

    SciTech Connect

    Nadas, Janos I; Vukovic, Sinisa; Hay, Benjamin

    2012-01-01

    To gain an understanding of the role of an alkyl chloride as a hydrogen bond acceptor, geometries and interaction energies were calculated at the MP2/aug-cc-pVDZ level of theory for complexes between ethyl chloride and representative hydrogen donor groups. The results establish that these donors, which include hydrogen cyanide, methanol, nitrobenzene, pyrrole, acetamide, and N-methylurea, form X-H {hor_ellipsis} Cl hydrogen bonds (X = C, N, O) of weak to moderate strength, with {Delta}E values ranging from -2.8 to -5.3 kcal/mol.

  3. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... Substances § 721.10045 Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  4. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... Substances § 721.10045 Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  5. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... Substances § 721.10045 Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  6. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... Substances § 721.10045 Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  7. 40 CFR 721.10487 - Alkylbenzenes sulfonic acids, metal salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkylbenzenes sulfonic acids, metal... Specific Chemical Substances § 721.10487 Alkylbenzenes sulfonic acids, metal salts (generic). (a) Chemical... as alkylbenzenes sulfonic acids, metal salts (PMNs P-04-599, P-04-600, P-04-605, and P-04-606)...

  8. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  9. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  10. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  11. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  12. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  13. 40 CFR 721.10474 - Substituted amino ethane sulfonic acid salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted amino ethane sulfonic acid... Specific Chemical Substances § 721.10474 Substituted amino ethane sulfonic acid salt (generic). (a... generically as substituted amino ethane sulfonic acid salt (PMN P-04-107) is subject to reporting under...

  14. 40 CFR 721.10633 - Aromatic sulfonic acid amino azo dye salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Aromatic sulfonic acid amino azo dye... Specific Chemical Substances § 721.10633 Aromatic sulfonic acid amino azo dye salts (generic). (a) Chemical... as aromatic sulfonic acid amino azo dye salts (PMN P-12-276) is subject to reporting under...

  15. 40 CFR 721.10474 - Substituted amino ethane sulfonic acid salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted amino ethane sulfonic acid... Specific Chemical Substances § 721.10474 Substituted amino ethane sulfonic acid salt (generic). (a... generically as substituted amino ethane sulfonic acid salt (PMN P-04-107) is subject to reporting under...

  16. 40 CFR 721.10633 - Aromatic sulfonic acid amino azo dye salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aromatic sulfonic acid amino azo dye... Specific Chemical Substances § 721.10633 Aromatic sulfonic acid amino azo dye salts (generic). (a) Chemical... as aromatic sulfonic acid amino azo dye salts (PMN P-12-276) is subject to reporting under...

  17. 40 CFR 721.9674 - Sulfonated-copper phthalocyanine salt of a triarylmethane dye (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sulfonated-copper phthalocyanine salt... Significant New Uses for Specific Chemical Substances § 721.9674 Sulfonated-copper phthalocyanine salt of a... chemical substance identified generically as sulfonated-copper phthalocyanine salt of a triarylmethane...

  18. 40 CFR 721.9674 - Sulfonated-copper phthalocyanine salt of a triarylmethane dye (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Sulfonated-copper phthalocyanine salt... Significant New Uses for Specific Chemical Substances § 721.9674 Sulfonated-copper phthalocyanine salt of a... chemical substance identified generically as sulfonated-copper phthalocyanine salt of a triarylmethane...

  19. 40 CFR 721.9674 - Sulfonated-copper phthalocyanine salt of a triarylmethane dye (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Sulfonated-copper phthalocyanine salt... Significant New Uses for Specific Chemical Substances § 721.9674 Sulfonated-copper phthalocyanine salt of a... chemical substance identified generically as sulfonated-copper phthalocyanine salt of a triarylmethane...

  20. 40 CFR 721.9674 - Sulfonated-copper phthalocyanine salt of a triarylmethane dye (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Sulfonated-copper phthalocyanine salt... Significant New Uses for Specific Chemical Substances § 721.9674 Sulfonated-copper phthalocyanine salt of a... chemical substance identified generically as sulfonated-copper phthalocyanine salt of a triarylmethane...