Asymmetric Conjugate Addition of Oxindoles to 2-Chloroacrylonitrile: A Highly Effective Organocatalytic Strategy for Simultaneous Construction of 1,3-Nonadjacent Stereocenters Leading to Chiral Pyrroloindolines
作者:Xin Li、Sanzhong Luo、Jin-Pei Cheng
DOI:10.1002/chem.201002563
日期:2010.12.27
Chiral pyrroloindoles: A highly enantioselective catalytic conjugate addition of 3‐substituted oxindoles with 2‐chloroacrylonitrile has been developed with a readily accessible alkyl bifunctional tertiary amine thiourea catalyst. Excellent stereoselectivity of up to >30:1 diastereomeric ratio and 99 % enantiomeric excess was achieved. The obtained Michael products could be easily converted to chiral
Catalytic Asymmetric Four-Component Reaction for the Rapid Construction of 3,3-Disubstituted 3-Indol-3′-yloxindoles
作者:Changcheng Jing、Dong Xing、Wenhao Hu
DOI:10.1021/acs.orglett.5b02160
日期:2015.9.4
A Rh(II)/chiral phosphoric acid cocatalyzed four-component reaction of indoles, 3-diazooxindoles, arylamines, and ethyl glyoxylate is developed, offering an extremely efficient strategy for the construction of 3,3-disubstituted 3-indol-3'-yloxindoles with excellent diastereoselectivities and high to excellent enantioselectivities. This transformation is proposed to proceed through a Mannichtype trapping of the zwitterionic intermediate generated from a metal carbene and an indole with an iminoester derived from an arylamine and a glyoxylate.