Organocatalyzed Michael–Michael Cascade Reaction: Asymmetric Synthesis of Polysubstituted Chromans
作者:Zhen-Xin Jia、Yong-Chun Luo、Xi-Na Cheng、Peng-Fei Xu、Yu-Cheng Gu
DOI:10.1021/jo400476b
日期:2013.7.5
An enantioselective cascade Michael Michael reaction between chalcones enolates and nitromethane catalyzed by a bifunctional thiourea is developed. This reaction provides a mild but efficient approach to chiral benzopyrans bearing three consecutive stereocenters in high yields with excellent stereoselectivities, and the benzopyrans can be easily transformed to the corresponding tricyclic product.