Cu(i)-Catalyzed asymmetric exo-selective synthesis of substituted pyrrolidines via a 1,3-dipolar cycloaddition reaction

Abstract

An (R)-DM-BINAP/Cu(CH₃CN)₄BF₄ complex catalyzed exo-selective asymmetric 1,3-dipolar cycloaddition (1,3-DCA) reaction of imino esters with α,β-unsaturated pyrazoleamides has been developed. A series of highly functionalized pyrrolidines with multiple stereogenic centers were obtained with good yields and diastereoselectivities and excellent enantioselectivities (up to 99% ee).