Rh(III)-Catalyzed [4 + 2] Annulation and Dehydrogenative Annulation of N-Chloroimines with Maleimides

We herein report a Rh(III)-catalyzed C–H bond coupling of N-chloroimines with maleimides, in which the [4 + 2] annulation and dehydrogenative annulation processes can be selectively achieved by simply adjusting the reaction conditions. This protocol is compatible with various functional groups, shows exquisite selectivity, and presents a concise synthetic procedure to respective products in moderate to good yields. With all these merits, this strategy may be applicable in the construction of related azaheterocyclic skeletons.