Palladium-Catalyzed Multicomponent Assembly of (Z)‑Alkenylborons via Carbopalladation/Boronation/Retro-Diels–Alder Cascade Reaction

A palladium-catalyzed multicomponent cascade reaction of aryl iodides, oxanorbornadiene, and diborns to access (Z)-alkenylborons is reported. This transformation proceeds through the sequential carbopalladation/boronation/retro-Diels–Alder domino reaction. The oxanorbornadiene used in this reaction serves as an acetylene surrogate, which is generated via a retro-Diels–Alder reaction. Such a stereoselective and scalable approach has a wide range of functional group tolerance and good substrate universality.