Rhodium(III)-Catalyzed Oxidative Cross-Coupling of Unreactive C(sp)-H Bonds with C(sp)-H Bonds.

The development of the oxidative cross-coupling of unreactive C(sp)-H bonds with (hetero)arene C(sp)-H bonds is considerably appealing, yet conceptually and practically challenging. Here, we disclose the rhodium-catalyzed oxidative heteroarylation of unactivated C(sp)-H bonds with heteroarene C(sp)-H bonds. This method provides a step-economic route to β-heteroarylated 2-ethylpyridine derivatives, which exhibits relatively broad substrate scope, high tolerance level of sensitive functional groups, and high selectivity. The protocol can also be extended to the coupling reaction between 8-methylquinoline derivatives and heteroarenes.