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

摘要

A facile synthesis of 3-hydroxy-3-(trifluoromethyl)-1H-pyrrol-2(3H)-ones based on trifluoroacetic acid-catalyzed condensation-cyclization reactions of beta-enamino esters and ethyl trifluoropyruvate is described. These reactions afford a series of alpha-trifluoromethylated gamma-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. (C) 2014 Elsevier Ltd. All rights reserved.