SCpRh(III)-Catalyzed Enantioselective Synthesis of Atropisomers by C2-Arylation of Indoles with 1-Diazonaphthoquinones

The Rh(III)-catalyzed highly enantioselective C2-arylation of indole derivatives with 1-diazonaphthoquinones is reported. In the presence of 2.5 mol % SCpRh complex and 20 mol % AgNO3, the C2-arylation reactions of indoles proceeded smoothly, affording a wide range of C2-arylated indole atropisomers in good yields and enantioselectivity (<= 96% yield, <= 97% ee) under mild conditions. The method displays a broad substrate scope and good functional group tolerance.