Asymmetric NHC-Catalyzed Aza-Diels?Alder Reactions: Highly Enantioselective Route to α?Amino Acid Derivatives and DFT Calculations

摘要

ABSTRACT: A facile N-heterocyclic carbene catalytic enantioselective aza-Diels?Alder reaction of oxodiazenes with α-chloroaldehydes as dienophile precursors is reported, with excellent enantioselectivity (ee > 99%) and excellent yield (up to 93%). DFT study showed that cis-TSa, formed from a top face approach of oxodiazene to cis-IIa, is the most favorable transition state and is consistent with the experimental observations.