Rh(III)-Catalyzed Selective Olefination of N-Carboxamide Indoles with Unactivated Olefins at Room Temperature via an Internal Oxidation

A mild, convenient, and effective Rh(III)-catalyzed site-selective C2-alkenylation of N-carboxamide indoles with unactivated alkenes at room temperature via an internal oxidation is described. The present olefination reaction was well-studied with plentiful indole N-carboxamides as well as unfunctionalized/functionalized unactivated alkenes. In this reaction, the directing group containing N-OMe acts as an internal oxidant. A possible reaction mechanism involving C-H activation/insertion/internal oxidation followed by protonation is proposed and supported by the deuterium-labeling studies.