Catalytic Enantioselective Halocyclizations to Access Benzoxazepinones and Benzoxazecinones.

We report a catalytic asymmetric halocyclization protocol to furnish benzoxazepinones and benzoxazecinones using (DHQ)2PHAL as the catalyst. Various halogenated benzoxazepinones and benzoxazecinones were achieved in excellent yields and enantioselectivities under mild conditions. A cocrystal structure of the substrate and the catalyst was studied.