Palladium-Catalyzed Hydroalkynylation of 1,3-Dienes: Access to 1,5-Enynes

Herein, we report an efficient strategy for palladium-catalyzed hydroalkynylation of 1,3-dienes using haloalkynes (X = Cl, Br) as alkynylating reagents and HCOONa as an economical hydrogen donor, successfully constructing synthetically valuable 1,5-enyne skeletons. This method demonstrates operational simplicity, mild reaction conditions, and scalability. Mechanistic investigations revealed that the formation of a π-allyl Pd(II) intermediate effectively suppressed β-H elimination, endowing the reaction with excellent regioselectivity and chemoselectivity control. The application potential in complex molecule construction was validated through the diverse derivatization of products.