Rh( <scp>iii</scp> )-catalyzed oxidative C–H cross-coupling between indoles and thiophenes/furanes

A concise synthesis of biheteroarenes through Rh(III)-catalyzed cross-dehydrogenative coupling (CDC) of indoles with thiophenes/furanes is developed. This reaction is accomplished with the assistance of a quinoline auxiliary, featuring mild reaction conditions, high regioselectivity and broad substrate scope. Some mechanistic details of this reaction have been clarified using a series of control experiments, suggesting a catalytic cycle. The readily accessible gram-scale synthesis, further transformation of products and practical construction of polycyclic heteroaromatic hydrocarbons (PHAHs) demonstrate the potential utility of this strategy.