Copper-Catalyzed Enantioselective Conjugate Addition of Grignard Reagents to alpha,beta-Unsaturated Esters

摘要

The development of catalyst systems for the enantioselective conjugate addition of organometallic reagents to a,p-unsatu-rated compounds has been the subject of intensive research over the past few decades.Whereas extraordinary advances have been made in asymmetric 1,4-additions to enones,lactones,and nitroalkenes,in the case of acyclic alpha,beta-unsaturated esters the progress has been limited,despite the enormous synthetic potential of the resulting enantiopure [3-substituted esters as building blocks for natural product synthesis.