Pyrrolidine-Camphor Derivative as an Organocatalyst for Asymmetic Michael Additions of α,α-Disubstituted Aldehydes to β-Nitroalkenes: Construction of Quaternary Carbon-Bearing Aldehydes under Solvent-Free Conditions
作者:Chihliang Chang、Ssu-Hsien Li、Raju Jannapu Reddy、Kwunmin Chen
DOI:10.1002/adsc.200800771
日期:2009.6
Abstractmagnified imageA novel pyrrolidine‐camphor organocatalyst 3 was designed, synthesized and proven to be an efficient catalyst for the asymmetric Michael reaction. Treatment of α,α‐disubstituted aldehydes with β‐nitroalkenes in the presence of 20 mol% organocatalyst 3 and 20 mol% benzoic acid under solvent‐free conditions provided the desired Michael product possessing an all‐carbon quaternary center with high chemical yields (up to 99% yield) and high levels of enantioselectivities (up to 95% ee).