A direct and selective synthesis of α,β-unsaturated piperidones by a new palladium-catalyzed cascade carbonylation is described. In the presented protocol, easily available propargylic alcohols react with aliphatic amines to provide a broad variety of interesting heterocycles. Key to the success of this transformation is a remarkable catalytic cleavage of the present carbon–carbon triple bond by using
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. lactam- cyclization - electrophilic addition -acid catalyst - microwave