DABCO-catalyzed branched N-allylic substitution of lactams and related unsaturated heteroaromatics

A mild and efficient method for the synthesis of branched N-allylic lactams and related N-heteroaromatics was reported. This strategy involves a DABCO-catalyzed SN2'-SN2' type N-allylic alkylation with Morita−Baylis−Hillman (MBH) carbonates. A wide scope of lactams and related N-heterocycles as well as MBH carbonates are well tolerated, and various branched N-substituted products were obtained in moderate to excellent yields. The utility of this methodology was further demonstrated by the gram-scale synthesis and diverse transformation of the products.