A Dual-Catalysis Approach to the Asymmetric Steglich Rearrangement and Catalytic Enantioselective Addition of O-Acylated Azlactones to Isoquinolines

A dual-catalysis approach, namely the combination of an achiral nucleophilic catalyst and a chiral anion-binding catalyst, was applied to the Steglich rearrangement to provide alpha,alpha-disubstituted amino acid derivatives in a highly enantioselective fashion. Replacement of the nucleophilic co-catalyst for isoquinoline resulted in a divergent reaction pathway and an unprecedented transformation of O-acylated azlactones. This strategy provided highly substituted alpha,beta-diamino acid derivatives with excellent levels of stereocontrol.