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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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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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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
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Highly regioselective synthesis of 3-alkenyl-oxindole ring-fused 3,3'-disubstituted Oxindoles via direct gamma-substitution of Morita-Baylis-Hillman carbonates of isatins with 3-substituted Oxindoles.
Organic & biomolecular chemistry, 2014Co-Authors: Feng Tingting, Ying Zhou, Xiongli Liu, Huang Xuan, Jing Dehong, Xiong-wei Liu, Feng-ming Guo, Weicheng YuanAbstract:The first phase transfer-catalysed direct γ-substitution of Morita–Baylis–Hillman carbonates of isatins with 3-substituted Oxindoles has been developed, which affords 3-alkenyl-oxindole ring-fused 3,3′-disubstituted Oxindoles in up to 83% yield under mild reaction conditions. Furthermore, their biological activity has been preliminarily demonstrated by in vitro evaluation against human prostate cancer cells PC-3 and human leukemia cells K562, using MTT-based assays with the commercially available standard drug Cisplatin as a positive control. Gratifyingly, compounds 3aa, 3ba and 3ca exhibited comparable in vitro inhibitory activities against human prostate cancer cells (PC-3) to Cisplatin. What's more, 3ba also had a good inhibition ability against human leukemia cells K562. These results indicate that 3-alkenyl-oxindole ring-fused 3,3′-disubstituted oxindole analogs may be potential lead compounds for further biological screening.
Rui Wang - One of the best experts on this subject based on the ideXlab platform.
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Recent Advances in Asymmetric Organocatalytic Construction of 3,3′‐Spirocyclic Oxindoles
Advanced Synthesis & Catalysis, 2013Co-Authors: Liang Hong, Rui WangAbstract:The asymmetric organocatalysis is definitely one of the most powerful and versatile tools for the rapid construction of various spirocyclic Oxindoles. In the past few years, a number of successful strategies based on organocatalysis have been developed for the construction of 3,3′-spirocyclic Oxindoles in high yields and excellent enantioselectivities under mild conditions. In this review, recent advances in this area are summarized and classified according to the spiro ring fused at the 3-position of the oxindole core.
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an asymmetric approach toward chiral multicyclic spiroOxindoles from isothiocyanato Oxindoles and unsaturated pyrazolones by a chiral tertiary amine thiourea catalyst
Chemical Communications, 2013Co-Authors: Qiao Chen, Jinyan Liang, Shoulei Wang, Dong Wang, Rui WangAbstract:The first organocatalytic Michael-cyclization cascade reaction between isothiocyanato Oxindoles and unsaturated pyrazolones has been developed. The multicyclic spiro[oxindole/thiobutyrolactam/pyrazolone] core structures containing three contiguous stereogenic centers, including two spiro quaternary centers, were prepared with excellent diastereo- (up to >20 : 1) and enantioselectivities (up to 99% ee).
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).
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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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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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
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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.
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highly efficient synthesis of spiro oxazolidine 2 thione Oxindoles with 3 isothiocyanato Oxindoles and aldehydes via an organocatalytic cascade aldol cyclization reaction
Tetrahedron, 2013Co-Authors: Wenbing Chen, Xiaomei Zhang, Wenyong Han, Yanyan Han, Weicheng YuanAbstract:Abstract A highly efficient method for the construction of a family of spiro[oxazolidine-2-thione-Oxindoles] with 3-isothiocyanato Oxindoles and aldehydes via a cascade aldol-cyclization process has been developed. This method provides access to spiro[oxazolidine-2-thione-oxindole] derivatives bearing two vicinal quaternary/tertiary stereocenters in up to 95% yield, 98:2 dr, and 89% ee with a chiral bifunctional thiourea–tertiary amine organocatalyst based on DPEN scaffold. Good reactivity was observed and the reaction could be completed within 1.0 min.
Amarnath Natarajan - One of the best experts on this subject based on the ideXlab platform.
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face selective reduction of the exocyclic double bond in isatin derived spirocyclic lactones
Organic and Biomolecular Chemistry, 2013Co-Authors: Sandeep Rana, Amarnath NatarajanAbstract:We report an unusual face selective reduction of the exocyclic double bond in the α-methylene-γ-butyrolactone motif of spiro-oxindole systems. The spiro-Oxindoles were assembled by an indium metal mediated Barbier-type reaction followed by an acid catalyzed lactonization.
