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

An efficient approach to prepare trifluoromethyl-α-carbolines and ester group-substituted α-carbolines via the tandem cyclization reaction of 2-(2-aminophenyl)­acetonitriles and trifluoromethyl 1,3-diones or β,γ-unsaturated α-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.