Ming-Phos/Copper(I)-Catalyzed Asymmetric Intermolecular [3+2] Cycloaddition of Azomethine Ylides with Trifluoromethyl Enones

Chiral pyrrolidine skeletons containing trifluoromethyl group are core structural motifs in many natural products and medicines. As a consequence, extensive studies have been conducted on the exploitation of efficient methods for the asymmetric synthesis of such compounds. In this paper, Ming-Phos/Cu(I)-catalyzed asymmetric intermolecular [3+2] cycloaddition reaction of azomethine ylides and beta-trifluoromethyl-alpha,beta-unsaturated ketone was reported. A broad substrate scope was observed with high yield and enantioselectivity (up to 99% yield and 98% ee). The method is featured by its mild conditions, simple operation, easily available ligands and good functional group compatibility.