Using Conveniently Designed α‐Amino Ketones in Michael Reactions under Iminium Catalysis: Enantioselective Synthesis of γ‐Lactams and γ‐Amino‐δ‐keto Esters

Abstract

AbstractThe behaviour of aminoacetophenones as Michael donors in catalytic enantioselective Michael reactions with α,β‐unsaturated aldehydes under iminium activation has been studied. These compounds react with each other in the presence of catalytic amounts of a chiral secondary amine through a Michael/hemiaminal formation cascade process which proceeds with high yields and enantiocontrol. Elaboration of these adducts by oxidation allows the easy access to chiral disubstituted γ‐lactams and other synthetically useful chiral building blocks such as γ‐amino‐δ‐keto esters or β‐substituted δ‐oxoamides are accessible from the obtained adducts by simple transformations.