Copper-Catalyzed Tandem O-Vinylation of Arylhydroxylamines/[3,3]-Rearrangement/Cyclization: Synthesis of Highly Substituted Indoles and Benzoindoles

Herein, we developed a copper-catalyzed O-vinylation of arylhydroxylamine using vinyliodonium salts as vinylation reagents to generate a transient O-vinyl-N-arylhydroxylamine that rapidly undergoes a [3,3]-sigmatropic rearrangement and subsequent cyclization/rearomatization to form a substituted indole. A wide range of highly substituted indoles and benzoindoles can be afforded in good yields. This approach is readily scalable, and the scope and application of this process are presented.