Copper(I)‐Catalyzed Asymmetric [3+2]‐Cycloaddition of α ‐Substituted Iminoesters with α ‐Trifluoromethyl α, β ‐Unsaturated Esters

Reported herein is an example of highly regio‐, diastereo‐ and enantioselective Cu(I)‐catalyzed intermolecular [3+2] cycloaddition reaction of α ‐substituted iminoesters with α ‐trifluoromethyl α,β ‐unsaturated esters. This novel strategy provided a facile access to pyrrolidines with two skipped (aza)quaternary stereocenters including a CF 3 all‐carbon quaternary stereocenter. A broad substrate scope was observed and high yields (up to 94%) with excellent diastereoselectivity (up to >20 : 1 d.r .) and enantioselectivity (up to 98% ee ) were obtained.