Palladium‐Catalyzed α‐Selective Halogenation of Triptycene Using Sulfur Directing Group

Abstract Functionalized triptycene derivatives have attracted significant research interest because of their potential applications in many research fields. Although the conventional Diels‐Alder reaction of anthracenes with benzynes has been a versatile synthetic tool for functionalized triptycenes, it is hardly possible to control the product regioselectivity. In this report, we demonstrate the selective synthesis of 1,8,13‐trisubstituted triptycenes by Pd‐catalyzed α‐bromination. As for the directing group, SMe group was the most effective to facilitate the halogenation of the proximal three benzene rings. The obtained product was further derivatized through allylation and Rh‐catalyzed hydroboration reactions.