Highly Regio‐, Diastereo‐, and Enantioselective Synthesis of Tetrahydroazepines and Benzo[ b ]oxepines through Palladium‐Catalyzed [4+3] Cycloaddition Reactions

A novel Pd 0 ‐catalyzed asymmetric [4+3] annulation reaction of two readily accessible starting materials has been developed for building seven‐membered heterocyclic architectures. The potential [3+2] side pathway could be suppressed though fine tuning of the conditions. A broad scope of cycloaddition donors and acceptors participated in the transformation with excellent chemo‐, regio‐, diastereo‐, and enantioselectivtities, leading to valuable tetrahydroazepines and benzo[ b ]oxepines.