Palladium-catalyzed [4 + 3] annulation of 2-bromobiphenyls and epoxides for the assembly of dihydrodibenzo[b,d]oxepines

A palladium-catalyzed [4 + 3] annulation of 2-bromobiphenyls and epoxides for the construction of dihydrodibenzo[b,d]oxepines is reported. This approach involves direct C-H and C-O bond activation followed by a ring annulation and features readily available starting materials, a broad substrate scope, good step economy and good scalability.