Rhodium-Catalyzed Successive C–H Bond Functionalizations To Synthesize Complex Indenols Bearing a Benzofuran Unit

Abstract

An efficient rhodium-catalyzed redox-neutral annulations of N-phenoxyacetamides and ynones via successive double C–H bond activations has been developed. A series of novel and complex indenols bearing a benzofuran unit were generated with moderate to excellent regioselecetivities under mild conditions. Adding N-ethylcyclohexanamine (CyNHEt) could restrict the formation of the mono C–H bond activation byproduct, which is not the intermediate of the reaction demonstrated via the mechanistic investigations.