Phosphine-Catalyzed Enantioselective γ-Addition of 3-Substituted Oxindoles to 2,3-Butadienoates and 2-Butynoates: Use of Prochiral Nucleophiles
作者:Tianli Wang、Weijun Yao、Fangrui Zhong、Guo Hao Pang、Yixin Lu
DOI:10.1002/anie.201307757
日期:2014.3.10
first phosphine‐catalyzed enantioselective γ‐addition with prochiral nucleophiles and 2,3‐butadienoates as the reaction partners has been developed. Both 3‐alkyl‐ and 3‐aryl‐substitutedoxindoles could be employed in this process, which is catalyzed by a chiral phosphine that is derived from an amino acid, thus affording oxindoles that bear an all‐carbon quaternary center at the 3‐position in high yields
highly carbon‐selective difluoromethylation of soft carbon nucleophiles including β‐ketoesters, malonates, oxindoles, benzofuranones and ketenesilylacetals with a difluoromethylated sulfonium ylide under mild conditions was described. Mechanistic studies suggest that these difluoromethylating reactions proceed via a difluorocarbene pathway.
Asymmetric Organocatalytic Synthesis of 3-Diarylmethine-Substituted Oxindoles Bearing a Quaternary Stereocenter via 1,6-Conjugate Addition to <i>para</i>-Quinone Methides
作者:Kun Zhao、Ying Zhi、Ai Wang、Dieter Enders
DOI:10.1021/acscatal.5b02519
日期:2016.2.5
A highly stereoselective organocatalytic 1,6-conjugate addition of 3-substituted oxindoles to para-quinone methides to construct all-carbon quaternary stereocenters is described. In the presence of 10 mol % of a bifunctional squaramide organocatalyst, this 1,6-addition reaction occurs with excellent yields, diastereoselectivities and very good enantioselectivities, providing an efficient approach to
Chiral Phosphine Catalyzed Asymmetric Michael Addition of Oxindoles
作者:Fangrui Zhong、Xiaowei Dou、Xiaoyu Han、Weijun Yao、Qiang Zhu、Yuezhong Meng、Yixin Lu
DOI:10.1002/anie.201208285
日期:2013.1.14
Bifunctional phosphines derived from amino acids mediate the asymmetric Michaeladdition of 3‐substituted oxindoles to activated alkenes (see scheme). Biologically relevant chiral 3,3‐disubstitutedoxindoles were thus prepared in high yields and with excellent enantioselectivities from 3‐aryl‐ and 3‐alkyl‐substituted oxindoles and various activated alkenes.
Bifunctional Quaternary Ammonium Salts Catalyzed Stereoselective Conjugate Addition of Oxindoles to Electron-Deficient β-Haloalkenes
作者:Qiaowen Jin、Changwu Zheng、Gang Zhao、Gang Zou
DOI:10.1021/acs.joc.7b00571
日期:2017.5.5
A highly Z-selective asymmetric conjugate addition of 3-substitutedoxindoles to β-haloalkene ketones/esters catalyzed by readily available chiral bifunctional quaternary ammonium salts is reported. This reaction provides efficient access to a range of 2-oxoindole derivatives bearing a thermodynamically unstable Z-olefin structure and a chiral quaternary carbon center in high yields (up to 90%) and