A facile synthesis of 3-hydroxy-3-(trifluoromethyl)-1H-pyrrol-2(3H)-ones with Brønsted acid-catalyzed condensation–cyclization reactions of β-enamino esters and ethyl trifluoropyruvate

A facile synthesis of 3-hydroxy-3-(trifluoromethyl)-1H-pyrrol-2(3H)-ones based on trifluoroacetic acid-catalyzed condensation–cyclization reactions of β-enamino esters and ethyl trifluoropyruvate is described. These reactions afford a series of α-trifluoromethylated γ-lactam compounds in good to excellent yields under mild conditions. A preliminary trial of an asymmetric catalytic version with chiral BINOL-derived phosphoric acid as enantioselective catalyst was conducted and showed promising enantioselectivity of the desired product.

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