A New and Effective One-Pot Synthesis of Polysubstituted Carbazoles Starting from β-Nitro-β,γ-Unsaturated-Ketones and Indoles

Abstract

Herein, we report a new one-pot synthesis of polysubstituted carbazoles starting from β-nitro-β,γ-unsaturated-ketones and indoles. The process is based on a Friedel-Crafts reaction of indoles to nitroolefins supported by 2,2,2-trifluoroethanol (TFE) followed by an acidic-promoted and microwave-assisted intramolecular cyclization, that involves the elimination of both nitrous acid and water molecules. Products were obtained in satisfactory to good overall yields (55–78%).