Rh(III)-catalyzed Oxidative C-H Cross-Coupling between Indoles and Thiophenes/Furanes

Abstract

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