Site-Selective C–H Functionalization of <i>N</i>‑Aryl and <i>N</i>‑Heteroaryl Piperidines, Morpholines, and Piperazines Controlled by a Chiral Dirhodium Tetracarboxylate Catalyst

Rhodium-catalyzed C–H insertion by donor/acceptor carbenes is a useful transformation in organic synthesis. However, the site-selectivity of the C–H transformation on the target molecule is often a major issue. Site-selective C–H functionalizations of challenging substrates like N-aryl- and N-heteroaryl piperidines could be achieved through chiral rhodium carbene intermediates, leading to the formation of highly stereoselective C-2 products. In addition, N-aryl morpholines and piperazines were selectively reacted at the α position to the N-aryl group.