Pd(II)-catalyzed dehydrogenative olefination of vinylic C-H bonds with allylic esters: general and selective access to linear 1,3-butadienes

This work demonstrates a general and efficient method to prepare conjugated dienes by Pd(II)-catalyzed direct olefination of unactivated alkenes with allylic esters and acrylates via vinylic C-H activation. Various aryl and heteroaryl alkenes as well as aliphatic alkenes all give the desired linear 1,3-butadienes with retention of the traditional leaving groups such as OAc and other carboxylic acid ester groups.