Palladium-catalyzed [2+1+1] annulation of norbornenes with (z)-bromostyrenes: synthesis of bismethylenecyclobutanes via twofold C(sp2)–H bond activation

Abstract

The first Pd-catalyzed intermolecular [2+1+1] annulation reaction of (Z)-bromostyrene derivatives and norbornenes has been realized. Bismethylenecyclobutane derivatives were obtained with high yields. The domino coupling reaction involves a double Heck-type coupling process, twofold C(sp²)–H bond activation and formation of three carbon–carbon bonds.