Highly Selective Construction of Medium-Sized Lactams by Palladium-Catalyzed Intramolecular Hydroaminocarbonylation of Aminoalkynes.

A novel palladium-catalyzed intramolecular hydroaminocarbonylation of aminoalkynes has been developed. This direct and operationally simple protocol provides a rapid and reliable approach to a diverse array of valuable seven- and eight-membered lactams with high chemoselectivity and regioselectivity. The high selectivity might be attributed to rational tuning the electronic nature of the amine moiety and the palladium catalyst, which enabled this transformation to proceed in the absence of acidic or any other additives under fairly mild reaction conditions. This method paves the way for the synthesis of medium-sized lactams.