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 enantioselective trifluoromethylthiolation of oxindoles using shelf-stable N-(trifluoromethylthio)phthalimide and a cinchona alkaloid catalyst
The organocatalytic enantioselectivetrifluoromethylthiolation of oxindoles employing N-(trifluoromethylthio)phthalimide as a stable, easy to handle CF3S-source has been developed. Optically active products with a quaternary stereogenic center bearing a CF3S-group are obtained in good yields and with good to excellent enantioselectivities.