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Weicheng Yuan - One of the best experts on this subject based on the ideXlab platform.
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regio and stereoselective 3 2 cycloaddition reaction access to isoxazole dispirobisOxindoles featuring three contiguous stereocenters
Organic and Biomolecular Chemistry, 2019Co-Authors: Shuang Chen, Guanlian Wang, Minyi Tian, Shengwen Xu, Min Zhang, Weicheng YuanAbstract:A novel methodology toward the diversity-oriented asymmetric construction of densely functionalized isoxazole-dispirobisOxindoles was developed. This approach is distinguished by an organocatalytic stereo- and appealing β-regioselective [3 + 2] cycloaddition reaction of 3-methyl-4-nitro-5-isatylidenyl-isoxazoles and 3-isothiocyanato Oxindoles. Complex polycyclic Oxindoles 3 featuring two different Oxindole moieties and three contiguous stereocenters were smoothly afforded in up to 96% yield, 96% ee, and >20 : 1 dr. The described method, which is different from our previous work of α-regioselective asymmetric annulation of 3-methyl-4-nitro-5-isatylidenyl-isoxazoles, is the first β-regioselective asymmetric annulation.
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Organocatalytic Asymmetric [3 + 2] Cycloaddition of N‑2,2,2-Trifluoroethylisatin Ketimines with β‑Trifluoromethyl Electron-Deficient Alkenes: Access to Vicinally Bis(trifluoromethyl)-Substituted 3,2′-Pyrrolidinyl SpiroOxindoles
2018Co-Authors: Yong You, Xiaomei Zhang, Zhen-hua Wang, Yong-zheng Chen, Weicheng YuanAbstract:N-2,2,2-Trifluoroethylisatin ketimines with β-trifluoromethyl enones, 3-trifluoroethylidene Oxindole, and 3-trifluoroethylidene benzofuranone can undergo asymmetric [3 + 2] cycloaddition, catalyzed by chiral bifunctional squaramide-tertiary amine catalysts, affording a wide spectrum of 3,2′-pyrrolidinyl spiroOxindoles. The significance of this protocol is highlighted by its extremely high efficiency in the construction of the structurally diverse spirocyclic Oxindoles, bearing a vicinally bis(trifluoromethyl)-substituted pyrrolidine moiety, including four contiguous stereocenters, in high yields with excellent stereocontrol
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organocatalytic asymmetric michael cyclization cascade reactions of 3 hydroxyOxindoles 3 aminoOxindoles with α β unsaturated acyl phosphonates for the construction of spirocyclic Oxindole γ lactones lactams
Journal of Organic Chemistry, 2015Co-Authors: Lin Chen, Xiaomei Zhang, Ming-liang Zhang, Deng-feng Yue, Weicheng YuanAbstract:Enantioselective Michael/cyclization cascade reactions of 3-hydroxyOxindoles/3-aminoOxindoles with α,β-unsaturated acyl phosphonates by using a cinchonine derived squaramide as the catalyst were developed. A broad range of spirocyclic Oxindole-γ-lactones/lactams could be obtained in moderate to excellent yields (up to 98%) with good to excellent diastereo- and enantioselectivities (up to >99:1 dr and 97% ee) under mild conditions. This work represents the first example about the α,β-unsaturated acyl phosphonates for the asymmetric construction of spirocyclic Oxindoles.
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organocatalytic asymmetric michael friedel crafts cascade reaction of 3 pyrrolyl Oxindoles and α β unsaturated aldehydes for the construction of chiral spiro 5 6 dihydropyrido 1 2 a pyrrole 3 3 Oxindoles
Journal of Organic Chemistry, 2015Co-Authors: Yong You, Xiaomei Zhang, Baodong Cui, Jian Zuo, Jianqiang Zhao, Mingqiang Zhou, Weicheng YuanAbstract:An efficient and unprecedented organocatalytic asymmetric reaction of 3-pyrrolyl-Oxindoles with α,β-unsaturated aldehydes to generate spirocyclic Oxindole compounds was developed. The reactions were catalyzed by diphenylprolinol silyl ether and 2-fluorobenzoic acid via an asymmetric Michael/Friedel–Crafts cascade process, followed by dehydration with p-toluenesulfonic acid to afford a wide variety of structurally diverse spiro[5,6-dihydropyrido[1,2-a]pyrrole-3,3′-Oxindole] derivatives in high yields (up to 93%) and with high to excellent diastereo- and enantioselectivities (up to >99:1 dr and 97% ee).
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organocatalytic asymmetric michael addition of 3 substituted Oxindoles to α β unsaturated acyl phosphonates for the synthesis of 3 3 disubstituted Oxindoles with chiral squaramides
Organic and Biomolecular Chemistry, 2015Co-Authors: Lin Chen, Xiaomei Zhang, Jian Zuo, Yong You, Ming-liang Zhang, Jianqiang Zhao, Weicheng YuanAbstract:A highly enantioselective Michael addition of 3-monosubstituted Oxindoles to α,β-unsaturated acyl phosphonates with chiral squaramides as catalysts is investigated for the first time. A wide range of 3,3'-disubstituted Oxindole adducts bearing adjacent quaternary and tertiary stereogenic centres could be smoothly obtained in good yields (up to 98%), diastereo- (up to >99 : 1 dr) and enantioselectivities (up to 98% ee) with the developed protocols.
Xiaomei Zhang - One of the best experts on this subject based on the ideXlab platform.
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Organocatalytic Asymmetric [3 + 2] Cycloaddition of N‑2,2,2-Trifluoroethylisatin Ketimines with β‑Trifluoromethyl Electron-Deficient Alkenes: Access to Vicinally Bis(trifluoromethyl)-Substituted 3,2′-Pyrrolidinyl SpiroOxindoles
2018Co-Authors: Yong You, Xiaomei Zhang, Zhen-hua Wang, Yong-zheng Chen, Weicheng YuanAbstract:N-2,2,2-Trifluoroethylisatin ketimines with β-trifluoromethyl enones, 3-trifluoroethylidene Oxindole, and 3-trifluoroethylidene benzofuranone can undergo asymmetric [3 + 2] cycloaddition, catalyzed by chiral bifunctional squaramide-tertiary amine catalysts, affording a wide spectrum of 3,2′-pyrrolidinyl spiroOxindoles. The significance of this protocol is highlighted by its extremely high efficiency in the construction of the structurally diverse spirocyclic Oxindoles, bearing a vicinally bis(trifluoromethyl)-substituted pyrrolidine moiety, including four contiguous stereocenters, in high yields with excellent stereocontrol
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organocatalytic asymmetric michael cyclization cascade reactions of 3 hydroxyOxindoles 3 aminoOxindoles with α β unsaturated acyl phosphonates for the construction of spirocyclic Oxindole γ lactones lactams
Journal of Organic Chemistry, 2015Co-Authors: Lin Chen, Xiaomei Zhang, Ming-liang Zhang, Deng-feng Yue, Weicheng YuanAbstract:Enantioselective Michael/cyclization cascade reactions of 3-hydroxyOxindoles/3-aminoOxindoles with α,β-unsaturated acyl phosphonates by using a cinchonine derived squaramide as the catalyst were developed. A broad range of spirocyclic Oxindole-γ-lactones/lactams could be obtained in moderate to excellent yields (up to 98%) with good to excellent diastereo- and enantioselectivities (up to >99:1 dr and 97% ee) under mild conditions. This work represents the first example about the α,β-unsaturated acyl phosphonates for the asymmetric construction of spirocyclic Oxindoles.
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organocatalytic asymmetric michael friedel crafts cascade reaction of 3 pyrrolyl Oxindoles and α β unsaturated aldehydes for the construction of chiral spiro 5 6 dihydropyrido 1 2 a pyrrole 3 3 Oxindoles
Journal of Organic Chemistry, 2015Co-Authors: Yong You, Xiaomei Zhang, Baodong Cui, Jian Zuo, Jianqiang Zhao, Mingqiang Zhou, Weicheng YuanAbstract:An efficient and unprecedented organocatalytic asymmetric reaction of 3-pyrrolyl-Oxindoles with α,β-unsaturated aldehydes to generate spirocyclic Oxindole compounds was developed. The reactions were catalyzed by diphenylprolinol silyl ether and 2-fluorobenzoic acid via an asymmetric Michael/Friedel–Crafts cascade process, followed by dehydration with p-toluenesulfonic acid to afford a wide variety of structurally diverse spiro[5,6-dihydropyrido[1,2-a]pyrrole-3,3′-Oxindole] derivatives in high yields (up to 93%) and with high to excellent diastereo- and enantioselectivities (up to >99:1 dr and 97% ee).
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organocatalytic asymmetric michael addition of 3 substituted Oxindoles to α β unsaturated acyl phosphonates for the synthesis of 3 3 disubstituted Oxindoles with chiral squaramides
Organic and Biomolecular Chemistry, 2015Co-Authors: Lin Chen, Xiaomei Zhang, Jian Zuo, Yong You, Ming-liang Zhang, Jianqiang Zhao, Weicheng YuanAbstract:A highly enantioselective Michael addition of 3-monosubstituted Oxindoles to α,β-unsaturated acyl phosphonates with chiral squaramides as catalysts is investigated for the first time. A wide range of 3,3'-disubstituted Oxindole adducts bearing adjacent quaternary and tertiary stereogenic centres could be smoothly obtained in good yields (up to 98%), diastereo- (up to >99 : 1 dr) and enantioselectivities (up to 98% ee) with the developed protocols.
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quinine catalyzed asymmetric domino mannich cyclization reactions of 3 isothiocyanato Oxindoles with imines for the synthesis of spirocyclic Oxindoles
Tetrahedron, 2015Co-Authors: Mei Bai, Xiaomei Zhang, Baodong Cui, Jian Zuo, Yong You, Yong-zheng Chen, Jianqiang Zhao, Weicheng YuanAbstract:Abstract A range of structurally diverse chiral spiro[imidazolidine-2-thione-4,3′-Oxindole] compounds could be obtained via a domino Mannich-cyclization reaction of 3-isothiocyanato Oxindoles and imines with commercial quinine as catalyst under mild conditions. The protocol is significantly characterized by simple process, easily available catalyst, high reactivity, low catalyst loading (1 mol %), and good to excellent diastereo- and enantioselectivity (up to>99:1 dr and 97% ee). A plausible dual activation working model was tentatively proposed to account for the stereochemistry of the domino Mannich-cyclization process.
Lin Chen - One of the best experts on this subject based on the ideXlab platform.
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organocatalytic asymmetric michael cyclization cascade reactions of 3 hydroxyOxindoles 3 aminoOxindoles with α β unsaturated acyl phosphonates for the construction of spirocyclic Oxindole γ lactones lactams
Journal of Organic Chemistry, 2015Co-Authors: Lin Chen, Xiaomei Zhang, Ming-liang Zhang, Deng-feng Yue, Weicheng YuanAbstract:Enantioselective Michael/cyclization cascade reactions of 3-hydroxyOxindoles/3-aminoOxindoles with α,β-unsaturated acyl phosphonates by using a cinchonine derived squaramide as the catalyst were developed. A broad range of spirocyclic Oxindole-γ-lactones/lactams could be obtained in moderate to excellent yields (up to 98%) with good to excellent diastereo- and enantioselectivities (up to >99:1 dr and 97% ee) under mild conditions. This work represents the first example about the α,β-unsaturated acyl phosphonates for the asymmetric construction of spirocyclic Oxindoles.
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organocatalytic asymmetric michael addition of 3 substituted Oxindoles to α β unsaturated acyl phosphonates for the synthesis of 3 3 disubstituted Oxindoles with chiral squaramides
Organic and Biomolecular Chemistry, 2015Co-Authors: Lin Chen, Xiaomei Zhang, Jian Zuo, Yong You, Ming-liang Zhang, Jianqiang Zhao, Weicheng YuanAbstract:A highly enantioselective Michael addition of 3-monosubstituted Oxindoles to α,β-unsaturated acyl phosphonates with chiral squaramides as catalysts is investigated for the first time. A wide range of 3,3'-disubstituted Oxindole adducts bearing adjacent quaternary and tertiary stereogenic centres could be smoothly obtained in good yields (up to 98%), diastereo- (up to >99 : 1 dr) and enantioselectivities (up to 98% ee) with the developed protocols.
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Organocatalytic Asymmetric Michael/Cyclization Cascade Reactions of 3‑HydroxyOxindoles/3-AminoOxindoles with α,β-Unsaturated Acyl Phosphonates for the Construction of Spirocyclic Oxindole-γ-lactones/lactams
2015Co-Authors: Lin Chen, Xiaomei Zhang, Ming-liang Zhang, Deng-feng Yue, Weicheng YuanAbstract:Enantioselective Michael/cyclization cascade reactions of 3-hydroxyOxindoles/3-aminoOxindoles with α,β-unsaturated acyl phosphonates by using a cinchonine derived squaramide as the catalyst were developed. A broad range of spirocyclic Oxindole-γ-lactones/lactams could be obtained in moderate to excellent yields (up to 98%) with good to excellent diastereo- and enantioselectivities (up to >99:1 dr and 97% ee) under mild conditions. This work represents the first example about the α,β-unsaturated acyl phosphonates for the asymmetric construction of spirocyclic Oxindoles
Jian Zuo - One of the best experts on this subject based on the ideXlab platform.
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organocatalytic asymmetric michael friedel crafts cascade reaction of 3 pyrrolyl Oxindoles and α β unsaturated aldehydes for the construction of chiral spiro 5 6 dihydropyrido 1 2 a pyrrole 3 3 Oxindoles
Journal of Organic Chemistry, 2015Co-Authors: Yong You, Xiaomei Zhang, Baodong Cui, Jian Zuo, Jianqiang Zhao, Mingqiang Zhou, Weicheng YuanAbstract:An efficient and unprecedented organocatalytic asymmetric reaction of 3-pyrrolyl-Oxindoles with α,β-unsaturated aldehydes to generate spirocyclic Oxindole compounds was developed. The reactions were catalyzed by diphenylprolinol silyl ether and 2-fluorobenzoic acid via an asymmetric Michael/Friedel–Crafts cascade process, followed by dehydration with p-toluenesulfonic acid to afford a wide variety of structurally diverse spiro[5,6-dihydropyrido[1,2-a]pyrrole-3,3′-Oxindole] derivatives in high yields (up to 93%) and with high to excellent diastereo- and enantioselectivities (up to >99:1 dr and 97% ee).
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organocatalytic asymmetric michael addition of 3 substituted Oxindoles to α β unsaturated acyl phosphonates for the synthesis of 3 3 disubstituted Oxindoles with chiral squaramides
Organic and Biomolecular Chemistry, 2015Co-Authors: Lin Chen, Xiaomei Zhang, Jian Zuo, Yong You, Ming-liang Zhang, Jianqiang Zhao, Weicheng YuanAbstract:A highly enantioselective Michael addition of 3-monosubstituted Oxindoles to α,β-unsaturated acyl phosphonates with chiral squaramides as catalysts is investigated for the first time. A wide range of 3,3'-disubstituted Oxindole adducts bearing adjacent quaternary and tertiary stereogenic centres could be smoothly obtained in good yields (up to 98%), diastereo- (up to >99 : 1 dr) and enantioselectivities (up to 98% ee) with the developed protocols.
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quinine catalyzed asymmetric domino mannich cyclization reactions of 3 isothiocyanato Oxindoles with imines for the synthesis of spirocyclic Oxindoles
Tetrahedron, 2015Co-Authors: Mei Bai, Xiaomei Zhang, Baodong Cui, Jian Zuo, Yong You, Yong-zheng Chen, Jianqiang Zhao, Weicheng YuanAbstract:Abstract A range of structurally diverse chiral spiro[imidazolidine-2-thione-4,3′-Oxindole] compounds could be obtained via a domino Mannich-cyclization reaction of 3-isothiocyanato Oxindoles and imines with commercial quinine as catalyst under mild conditions. The protocol is significantly characterized by simple process, easily available catalyst, high reactivity, low catalyst loading (1 mol %), and good to excellent diastereo- and enantioselectivity (up to>99:1 dr and 97% ee). A plausible dual activation working model was tentatively proposed to account for the stereochemistry of the domino Mannich-cyclization process.
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preparation of 3 sulfonylated 3 3 disubstituted Oxindoles by the addition of sulfinate salts to 3 haloOxindoles
Journal of Organic Chemistry, 2015Co-Authors: Jian Zuo, Xiaomei Zhang, Jianqiang Zhao, Mingqiang Zhou, Weicheng YuanAbstract:An efficient method for the preparation of 3-sulfonylated 3,3-disubstituted Oxindole derivatives has been developed. The protocol involves a base-catalyzed addition of sulfinate salts to 3-haloOxindoles, affording a wide range of 3-sulfonylated 3,3-disubstituted Oxindoles in good to excellent yields under mild conditions. A preliminary trial of asymmetric catalytic version was conducted and gave promising enantioselectivity. The mechanism for the reaction was tentatively explored with the help of mass spectrometric analysis.
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quinine catalyzed asymmetric domino michael cyclization reaction for the synthesis of spirocyclic Oxindoles bearing two spiro quaternary centers and three consecutive stereocenters
Tetrahedron, 2014Co-Authors: Baodong Cui, Xiaomei Zhang, Jian Zuo, Weicheng YuanAbstract:An efficient organocatalytic diastereo- and enantioselective method for the construction of spirocyclic Oxindole derivatives bearing two Spiro quaternary centers and three consecutive stereocenters via a domino Michael/cyclization process has been developed. Using commercially available quinine as catalyst, the reactions of 3-isothiocyanato Oxindoles with unsaturated pyrazolones and unsaturated isoxazolones proceeded smoothly under mild reaction conditions for giving two classes of spirocyclic Oxindole compounds in high to excellent yields with moderate to good diastereoselectivities and enantioselectivities. A plausible dual activation working model was tentatively proposed to account for the stereochemistry of the domino Michael/cyclization process. (C) 2014 Published by Elsevier Ltd.
Jinpei Cheng - One of the best experts on this subject based on the ideXlab platform.
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asymmetric michael addition reaction of 3 substituted n boc Oxindoles to activated terminal alkenes catalyzed by a bifunctional tertiary amine thiourea catalyst
Organic and Biomolecular Chemistry, 2010Co-Authors: Sanzhong Luo, Jinpei ChengAbstract:The current article reports an organocatalytic strategy for the asymmetric catalysis of chiral Oxindoles bearing 3-position all-carbon quaternary stereocenters. Accordingly, highly enantioselective Michael addition reactions of 3-substituted Oxindoles to terminal alkenes have been developed by utilizing a bifunctional tertiary-amine thiourea catalyst. The reactions accommodate a number of Michael donor compounds (different substituted 3-aryl or methyl Oxindoles), and Michael acceptor compounds (vinyl ketones and vinyl sulfones) to give the desired Oxindole products with moderate to excellent yields (up to 99%) and moderate to excellent enantioselectivities (up to 91% ee).
