Preparation of α,β-Unsaturated Lactams through Intramolecular Electrophilic Carbamoylation of Alkenes

Abstract

A general synthetic method for the preparation of α,β-unsaturated lactams starting from alkenylchloroformamides has been developed. The reaction was complete within five minutes at 150 ˚C in N-methylpyrrolidone with a catalytic amount of HBr under microwave irradiation. Not only six-membered lactams, but also five- and seven-membered lactams were obtained in high yields.