Phase-transfer-catalyzed Asymmetric Alkylation with Epoxy Triflates as Alkylating Agents: Highly Stereoselective Synthesis of γ,δ-Epoxy-α-amino Acids

Abstract

Abstract Although alkyl sulfonates are commonly used for alkylating agents, there are very few reports on phase-transfer-catalyzed asymmetric alkylation with alkyl sulfonates. Herein, we report that the asymmetric reaction using glycine Schiff base 1 and optically pure epoxy triflates op-2 proceeded smoothly in the presence of phase-transfer catalyst (S,S)-4a to furnish γ,δ-epoxy-α-amino acids 3 in good yield with high enantioselectivity.