Synthesis of Trifluoromethyl- and Ester Group-Substituted α-Carbolines via Iron-Catalyzed Tandem Cyclization Reaction

An efficient approach to prepare trifluoromethyl-alpha-carbolines and ester group-substituted alpha-carbolines via the tandem cyclization reaction of 2-(2-aminophenyl)acetonitriles and trifluoromethyl 1,3-diones or beta,gamma-unsaturated alpha-ketoesters was reported. The transformation proceeded smoothly in the presence of catalytic environmental-benign iron salts, which are used to prepare the desired products in moderate to good yields.