The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Ulfh Dolling - One of the best experts on this subject based on the ideXlab platform.
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the expedient synthesis of 4 2 difluoro 5 7 trifluoromethyl imidazo 1 2 a pyrimidin 3 yl biphenyl 2 carbonitrile a gaba α2 3 agonist
Organic Process Research & Development, 2006Co-Authors: Mark Cameron, Bruce S Foster, Joseph E Lynch, Ulfh DollingAbstract:An expedient regioselective synthesis of a GABA α2/3 agonist 1 is described. The key step is an efficient regioselective palladium-catalyzed coupling of 7-trifluoromethylimidazo[1,2-a]pyrimidine (5) to 5‘-chloro-4,2‘-difluorobiphenyl-2-carbonitrile (15). The efficiency of this step was affected by the choice of solvent, ligand, and Tetrabutylammonium Salt additive.
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The Expedient Synthesis of 4,2‘-Difluoro-5‘-(7-trifluoromethyl- imidazo[1,2-a]pyrimidin-3-yl)biphenyl-2-carbonitrile, a GABA α2/3 Agonist
Organic Process Research & Development, 2006Co-Authors: Mark Cameron, Bruce S Foster, Joseph E Lynch, Yao-jun Shi, Ulfh DollingAbstract:An expedient regioselective synthesis of a GABA α2/3 agonist 1 is described. The key step is an efficient regioselective palladium-catalyzed coupling of 7-trifluoromethylimidazo[1,2-a]pyrimidine (5) to 5‘-chloro-4,2‘-difluorobiphenyl-2-carbonitrile (15). The efficiency of this step was affected by the choice of solvent, ligand, and Tetrabutylammonium Salt additive.
Lizhu Wu - One of the best experts on this subject based on the ideXlab platform.
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metal free desulfonylation reaction through visible light photoredox catalysis
European Journal of Organic Chemistry, 2013Co-Authors: Dengtao Yang, Jianji Zhong, Qingyuan Meng, Ming Xiang, Lizhu WuAbstract:The desulfonylation of -arylketosulfones has been achieved in good to excellent yields by using 3-W blue LEDs light, 1 mol-% organic dye eosin Y bis(Tetrabutylammonium Salt) as photocatalyst, and diisopropylethylamine as reducing agent. Mechanistic studies demonstrate that oxidative quenching of the excited eosin Y by -arylketosulfones plays a crucial role in the present photoredox catalytic cycle.
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Metal‐Free Desulfonylation Reaction Through Visible‐Light Photoredox Catalysis
European Journal of Organic Chemistry, 2013Co-Authors: Dengtao Yang, Jianji Zhong, Qingyuan Meng, Ming Xiang, Lizhu WuAbstract:The desulfonylation of -arylketosulfones has been achieved in good to excellent yields by using 3-W blue LEDs light, 1 mol-% organic dye eosin Y bis(Tetrabutylammonium Salt) as photocatalyst, and diisopropylethylamine as reducing agent. Mechanistic studies demonstrate that oxidative quenching of the excited eosin Y by -arylketosulfones plays a crucial role in the present photoredox catalytic cycle.
Mark Cameron - One of the best experts on this subject based on the ideXlab platform.
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the expedient synthesis of 4 2 difluoro 5 7 trifluoromethyl imidazo 1 2 a pyrimidin 3 yl biphenyl 2 carbonitrile a gaba α2 3 agonist
Organic Process Research & Development, 2006Co-Authors: Mark Cameron, Bruce S Foster, Joseph E Lynch, Ulfh DollingAbstract:An expedient regioselective synthesis of a GABA α2/3 agonist 1 is described. The key step is an efficient regioselective palladium-catalyzed coupling of 7-trifluoromethylimidazo[1,2-a]pyrimidine (5) to 5‘-chloro-4,2‘-difluorobiphenyl-2-carbonitrile (15). The efficiency of this step was affected by the choice of solvent, ligand, and Tetrabutylammonium Salt additive.
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The Expedient Synthesis of 4,2‘-Difluoro-5‘-(7-trifluoromethyl- imidazo[1,2-a]pyrimidin-3-yl)biphenyl-2-carbonitrile, a GABA α2/3 Agonist
Organic Process Research & Development, 2006Co-Authors: Mark Cameron, Bruce S Foster, Joseph E Lynch, Yao-jun Shi, Ulfh DollingAbstract:An expedient regioselective synthesis of a GABA α2/3 agonist 1 is described. The key step is an efficient regioselective palladium-catalyzed coupling of 7-trifluoromethylimidazo[1,2-a]pyrimidine (5) to 5‘-chloro-4,2‘-difluorobiphenyl-2-carbonitrile (15). The efficiency of this step was affected by the choice of solvent, ligand, and Tetrabutylammonium Salt additive.
Dengtao Yang - One of the best experts on this subject based on the ideXlab platform.
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metal free desulfonylation reaction through visible light photoredox catalysis
European Journal of Organic Chemistry, 2013Co-Authors: Dengtao Yang, Jianji Zhong, Qingyuan Meng, Ming Xiang, Lizhu WuAbstract:The desulfonylation of -arylketosulfones has been achieved in good to excellent yields by using 3-W blue LEDs light, 1 mol-% organic dye eosin Y bis(Tetrabutylammonium Salt) as photocatalyst, and diisopropylethylamine as reducing agent. Mechanistic studies demonstrate that oxidative quenching of the excited eosin Y by -arylketosulfones plays a crucial role in the present photoredox catalytic cycle.
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Metal‐Free Desulfonylation Reaction Through Visible‐Light Photoredox Catalysis
European Journal of Organic Chemistry, 2013Co-Authors: Dengtao Yang, Jianji Zhong, Qingyuan Meng, Ming Xiang, Lizhu WuAbstract:The desulfonylation of -arylketosulfones has been achieved in good to excellent yields by using 3-W blue LEDs light, 1 mol-% organic dye eosin Y bis(Tetrabutylammonium Salt) as photocatalyst, and diisopropylethylamine as reducing agent. Mechanistic studies demonstrate that oxidative quenching of the excited eosin Y by -arylketosulfones plays a crucial role in the present photoredox catalytic cycle.
Kumaresh Ghosh - One of the best experts on this subject based on the ideXlab platform.
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Naphthyridine amide–urea conjugate: a case toward selective fluorometric sensing of N-acetyl proline carboxylate
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2011Co-Authors: Kumaresh Ghosh, Tanmay SarkarAbstract:A simple neutral naphthyridine-based chemosensor 1, which selectively recognizes the Tetrabutylammonium Salt of N-acetyl-l-proline over the other N-acetyl-l-amino acid Salts studied in CHCl3 containing 0.1% DMSO, has been designed and synthesized. Moreover, the complexation-induced change in emission characteristics of 1 distinguishes the amino acid Salts examined from their conjugate acids. Interaction studies were performed by UV–vis, fluorescence and NMR spectroscopic methods. A simple neutral naphthyridine –based chemosensor 1, which selectively recognizes the Tetrabutylammonium Salt of N-acetyl-l-proline in CHCl3 containing 0.1% DMSO, has been designed and synthesized. The complexation-induced change in emission characteristics of 1 distinguishes the amino acid Salts from their conjugate acids.
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anthracene appended pyridinium amide urea conjugate in selective fluorometric sensing of l n acetylvaline Salt
Beilstein Journal of Organic Chemistry, 2010Co-Authors: Kumaresh Ghosh, Tanmay Sarkar, Asoke P ChattopadhyayAbstract:A new anthracene labeled pyridinium amide–urea conjugate 1 has been designed and synthesized. The receptor shows a different fluorometric response with L-N-acetylvaline and L-N-acetylalanine Salts in CH3CN in contrast to the other Salts of L-N-acetyl α-amino acids and (S)-α-hydroxy acids studied. Upon complexation of the Tetrabutylammonium Salt of L-N-acetylvaline, the emission of 1 increases accompanied by the formation of a new band at higher wavelength and this characteristic change distinguishes it from other anionic substrates studied. The binding interaction has been studied by 1H NMR, fluorescence and UV titration experiments.
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Anthracene appended pyridinium amide–urea conjugate in selective fluorometric sensing of L-N-acetylvaline Salt
Beilstein journal of organic chemistry, 2010Co-Authors: Kumaresh Ghosh, Tanmay Sarkar, Asoke P ChattopadhyayAbstract:A new anthracene labeled pyridinium amide-urea conjugate 1 has been designed and synthesized. The receptor shows a different fluorometric response with L-N-acetylvaline and L-N-acetylalanine Salts in CH₃CN in contrast to the other Salts of L-N-acetyl α-amino acids and (S)-α-hydroxy acids studied. Upon complexation of the Tetrabutylammonium Salt of L-N-acetylvaline, the emission of 1 increases accompanied by the formation of a new band at higher wavelength and this characteristic change distinguishes it from other anionic substrates studied. The binding interaction has been studied by ¹H NMR, fluorescence and UV titration experiments.
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Naphthyridine-based symmetrical and unsymmetrical pyridinium amides in sensing of biotin Salt
Supramolecular Chemistry, 2009Co-Authors: Kumaresh Ghosh, Avik Ranjan Sarkar, Tanushree SenAbstract:Two naphthyridine-based receptors have been designed and synthesised for biotin Salt. The compounds serve as good hosts for the detection of biotin carboxylate rather than biotin ester. The correct dispositions of the binding groups under an isophthaloyl spacer enable the receptors to bind both the cyclic urea and the carboxylate ends simultaneously with moderate binding constant values. The receptors are effective for the binding of Tetrabutylammonium Salt of biotin with a concomitant increase in the fluorescence of naphthyridine and show appreciable binding of biotin Salt in CH3CN containing 1.2% DMSO. The binding was monitored in CH3CN containing 1.2% DMSO and DMSO using 1H NMR, UV–vis and fluorescence spectroscopic methods.