Application of Indolyl Ynones in the Construction of Chiral Carbazoles and Pyrroloindolines by Organo and Metal Sequential Catalysis

The enantioselective synthesis of carbazoles and pyrroloindolines has been achieved through organo-catalyzed and metal sequential-catalyzed one-pot reactions of indolyl ynones. Chiral carbazoles can be synthesized from the reactions of indolyl ynones and nitroolefins through an organo-catalyzed Michael addition followed by a gold-catalyzed Friedel-Crafts reaction/aromatization process. The reactions of indolyl ynones and N-tosyl imines lead to the generation of pyrroloindolines via an organo-catalyzed Mannich reaction and a silver-catalyzed dearomatizing spirocyclization/N,N-acetalization cascade reaction.