Cinchona-alkaloid-based catalysts, and asymmetric alcoholysis of cyclic anhydrides using them
申请人:Deng Li
公开号:US20050043353A1
公开(公告)日:2005-02-24
One aspect of the present invention relates to cinchona-alkaloid-based catalysts. A second aspect of the invention relates to a method of preparing a derivatized cinchona alkaloid catalyst by reacting a cinchona-alkaloid with base and a compound that has a suitable leaving group. Another aspect of the present invention relates to a method of preparing a chiral, non-racemic compound from a prochiral cyclic anhydride or a meso cyclic anhydride, comprising the step of: reacting a prochiral cyclic anhydride or a meso cyclic anhydride with a nucleophile in the presence of a catalyst; wherein said prochiral cyclic anhydride or meso cyclic anhydride comprises an internal plane of symmetry or point of symmetry or both; thereby producing a chiral, non-racemic compound; wherein said catalyst is a derivatized cinchona-alkaloid. Yet another aspect of the present invention relates to a method of kinetic resolution, comprising the step of: reacting a racemic cyclic anhydride with an alcohol in the presence of a derivatized cinchona-alkaloid catalyst.
Elucidation of the active conformation of cinchona alkaloid catalyst and chemical mechanism of alcoholysis of meso anhydrides
作者:Hongming Li、Xiaofeng Liu、Fanghui Wu、Liang Tang、Li Deng
DOI:10.1073/pnas.1004439107
日期:2010.11.30
Complementary to enantioselective transformations of planar functionalities, catalyticdesymmetrization of meso compounds is another fundamentally important strategy for asymmetric synthesis. However, experimentally established stereochemical models on how a chiral catalyst discriminates between two enantiotopic functional groups in the desymmetrization of a meso substrate are particularly lacking