Thiourea-Catalyzed Highly Enantio- and Diastereoselective Additions of Oxindoles to Nitroolefins: Application to the Formal Synthesis of (+)-Physostigmine
作者:Tommy Bui、Salahuddin Syed、Carlos F. Barbas
DOI:10.1021/ja903520c
日期:2009.7.1
molecules. Most catalytic methods for the asymmetric syntheses of these compounds rely heavily on the use of transition-metal catalysts. In contrast, alternative catalytic procedures involving organocatalysis are scarce. Herein we disclose a conceptually novel organocatalytic approach to the syntheses of these materials using thiourea-catalyzed asymmetric 1,4-additions of oxindole derivatives to nitroolefins