The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Masahiro Murakami - One of the best experts on this subject based on the ideXlab platform.
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facile synthesis of 2 5 disubstituted thiazoles from terminal alkynes sulfonyl azides and thionoesters
Organic Letters, 2015Co-Authors: Tomoya Miura, Yuuta Funakoshi, Yoshikazu Fujimoto, Junki Nakahashi, Masahiro MurakamiAbstract:A sequential procedure for the synthesis of 2,5-disubstituted thiazoles from terminal alkynes, sulfonyl azides, and thionoesters is reported. A copper(I)-catalyzed 1,3-dipolar cycloaddition of terminal alkynes with sulfonyl azides affords 1-sulfonyl-1,2,3-Triazoles, which then react with thionoesters in the presence of a rhodium(II) catalyst. The resulting 3-sulfonyl-4-thiazolines subsequently aromatize into the corresponding 2,5-disubstituted thiazoles by elimination of the sulfonyl group.
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nickel catalysed denitrogenative alkyne insertion reactions of n sulfonyl 1 2 3 Triazoles
Chemical Communications, 2009Co-Authors: Tomoya Miura, Motoshi Yamauchi, Masahiro MurakamiAbstract:N-Sulfonyl-1,2,3-Triazoles reacted with alkynes in the presence of a nickel(0)/phosphinecatalyst to give substituted pyrroles, with the extrusion of molecular nitrogen; the triazole moiety isomerised to an α-imino diazo species, and the denitrogenative addition to nickel(0) was followed by the insertion of alkynes and reductive elimination.
Wanzhi Chen - One of the best experts on this subject based on the ideXlab platform.
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one pot three component synthesis of enamine functionalized 1 2 3 Triazoles via cu catalytic azide alkyne click cuaac and cu catalyzed vinyl nitrene transfer sequence
Organic Letters, 2017Co-Authors: Wei Zhou, Min Zhang, Wanzhi ChenAbstract:A number of enamine-functionalized 1,2,3-triazole derivatives have been prepared via the Cu-catalyzed three-component reaction of terminal alkyne, azide, and 2H-azirine. The reaction proceeds through insertion of vinyl nitrene into the C–Cu bond of the triazolyl-Cu species, providing an efficient and step- and atom-economic approach to the enamine-bearing polysubstituted 1,2,3-Triazoles. The resulting Triazoles were easily transformed to trisubstituted pyrazoles in the presence of a Rh catalyst.
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One-Pot Three-Component Synthesis of Enamine-Functionalized 1,2,3-Triazoles via Cu-Catalytic Azide–Alkyne Click (CuAAC) and Cu‑Catalyzed Vinyl Nitrene Transfer Sequence
2016Co-Authors: Wei Zhou, Min Zhang, Wanzhi ChenAbstract:A number of enamine-functionalized 1,2,3-triazole derivatives have been prepared via the Cu-catalyzed three-component reaction of terminal alkyne, azide, and 2H-azirine. The reaction proceeds through insertion of vinyl nitrene into the C–Cu bond of the triazolyl-Cu species, providing an efficient and step- and atom-economic approach to the enamine-bearing polysubstituted 1,2,3-Triazoles. The resulting Triazoles were easily transformed to trisubstituted pyrazoles in the presence of a Rh catalyst
Tomoya Miura - One of the best experts on this subject based on the ideXlab platform.
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facile synthesis of 2 5 disubstituted thiazoles from terminal alkynes sulfonyl azides and thionoesters
Organic Letters, 2015Co-Authors: Tomoya Miura, Yuuta Funakoshi, Yoshikazu Fujimoto, Junki Nakahashi, Masahiro MurakamiAbstract:A sequential procedure for the synthesis of 2,5-disubstituted thiazoles from terminal alkynes, sulfonyl azides, and thionoesters is reported. A copper(I)-catalyzed 1,3-dipolar cycloaddition of terminal alkynes with sulfonyl azides affords 1-sulfonyl-1,2,3-Triazoles, which then react with thionoesters in the presence of a rhodium(II) catalyst. The resulting 3-sulfonyl-4-thiazolines subsequently aromatize into the corresponding 2,5-disubstituted thiazoles by elimination of the sulfonyl group.
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nickel catalysed denitrogenative alkyne insertion reactions of n sulfonyl 1 2 3 Triazoles
Chemical Communications, 2009Co-Authors: Tomoya Miura, Motoshi Yamauchi, Masahiro MurakamiAbstract:N-Sulfonyl-1,2,3-Triazoles reacted with alkynes in the presence of a nickel(0)/phosphinecatalyst to give substituted pyrroles, with the extrusion of molecular nitrogen; the triazole moiety isomerised to an α-imino diazo species, and the denitrogenative addition to nickel(0) was followed by the insertion of alkynes and reductive elimination.
Wouter De Looff - One of the best experts on this subject based on the ideXlab platform.
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bioisosteric replacements of the pyrazole moiety of rimonabant synthesis biological properties and molecular modeling investigations of thiazoles Triazoles and imidazoles as potent and selective cb1 cannabinoid receptor antagonists
Journal of Medicinal Chemistry, 2005Co-Authors: Josephus H M Lange, Herman H Van Stuivenberg, Hein K A C Coolen, Tiny J P Adolfs, Andrew C Mccreary, Hiskias G Keizer, Henri C Wals, Willem Veerman, Alice J M Borst, Wouter De LooffAbstract:Series of thiazoles, Triazoles, and imidazoles were designed as bioisosteres, based on the 1,5-diarylpyrazole motif that is present in the potent CB1 receptor antagonist rimonabant (SR141716A, 1). A number of target compounds was synthesized and evaluated in cannabinoid (hCB1 and hCB2) receptor assays. The thiazoles, Triazoles, and imidazoles elicited in vitroCB1 antagonistic activities and in general exhibited considerable CB1 vs CB2 receptor subtype selectivities, thereby demonstrating to be cannabinoid bioisosteres of the original diarylpyrazole class. Some key representatives in the imidazole series showed potent pharmacological in vivo activities after oral administration in both a CB agonist-induced hypotension model and a CB agonist-induced hypothermia model. Molecular modeling studies showed a close three-dimensional structural overlap between the key compound 62 and rimonabant. A structure−activity relationship (SAR) study revealed a close correlation between the biological results in the imidazo...
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bioisosteric replacements of the pyrazole moiety of rimonabant synthesis biological properties and molecular modeling investigations of thiazoles Triazoles and imidazoles as potent and selective cb1 cannabinoid receptor antagonists
Journal of Medicinal Chemistry, 2005Co-Authors: Josephus H M Lange, Herman H Van Stuivenberg, Hein K A C Coolen, Tiny J P Adolfs, Andrew C Mccreary, Hiskias G Keizer, Henri C Wals, Willem Veerman, Alice J M Borst, Wouter De LooffAbstract:Series of thiazoles, Triazoles, and imidazoles were designed as bioisosteres, based on the 1,5-diarylpyrazole motif that is present in the potent CB(1) receptor antagonist rimonabant (SR141716A, 1). A number of target compounds was synthesized and evaluated in cannabinoid (hCB(1) and hCB(2)) receptor assays. The thiazoles, Triazoles, and imidazoles elicited in vitro( )()CB(1) antagonistic activities and in general exhibited considerable CB(1) vs CB(2) receptor subtype selectivities, thereby demonstrating to be cannabinoid bioisosteres of the original diarylpyrazole class. Some key representatives in the imidazole series showed potent pharmacological in vivo activities after oral administration in both a CB agonist-induced hypotension model and a CB agonist-induced hypothermia model. Molecular modeling studies showed a close three-dimensional structural overlap between the key compound 62 and rimonabant. A structure-activity relationship (SAR) study revealed a close correlation between the biological results in the imidazole and pyrazole series.
Wim Dehaen - One of the best experts on this subject based on the ideXlab platform.
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tandem organocatalyzed knoevenagel condensation 1 3 dipolar cycloaddition towards highly functionalized fused 1 2 3 Triazoles
European Journal of Organic Chemistry, 2015Co-Authors: Jubi John, Joice Thomas, Nikita Parekh, Wim DehaenAbstract:Facile synthesis of fused 1,2,3-Triazoles by a proline-catalyzed reaction of an azido aldehyde and a nitroalkane is elaborated. The present tandem protocol proceeds via an organocatalytic Knoevenagel condensation of the azido aldehyde and nitroalkane followed by intramolecular azide–nitroalkene cycloaddition. The functionalized bicyclic triazole is obtained by elimination of HNO2 from the cycloadduct. Application of this strategy enabled us to synthesize a range of functionalised 5–7 membered ring fused Triazoles. The reaction calls for mild conditions, affords high yields, and results in good regiospecificity while displaying excellent substrate scope.
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a metal free three component reaction for the regioselective synthesis of 1 4 5 trisubstituted 1 2 3 Triazoles
Angewandte Chemie, 2014Co-Authors: Joice Thomas, Jubi John, Nikita Parekh, Wim DehaenAbstract:A metal-free three-component reaction to synthesize 1,4,5-trisubstituted 1,2,3-Triazoles from readily available building blocks, such as aldehydes, nitroalkanes, and organic azides, is described. The process is enabled by an organocatalyzed Knoevenagel condensation of the formyl group with the nitro compound, which is followed by the 1,3-dipolar cycloaddition of the azide to the activated alkene. The reaction features an excellent substrate scope, and the products are obtained with high yield and regioselectivity. This method can be utilized for the synthesis of fused triazole heterocycles and materials with several triazole moieties.