Convergent Synthesis of Diverse Nitrogen Heterocycles via Rh(III)-Catalyzed C-H Conjugate Addition/Cyclization Reactions.

The development of Rh(III)-catalyzed C-H conjugate addition/cyclization reactions that provide access to synthetically useful fused bi- and tricyclic nitrogen heterocycles is reported. A broad scope of C-H functionalization substrates and electrophilic olefin coupling partners is effective, and depending on the nature of the directing group, cyclic imide, amide, or heteroaromatic products are obtained. An efficient synthesis of a pyrrolophenanthridine alkaloid natural product, oxoassoanine, highlights the utility of this method.