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

Abstract

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,-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.

Diverse Synthesis of Fused Polyheterocyclic Compounds via [3 + 2] Cycloaddition of In Situ-Generated Heteroaromatic N-Ylides and Electron-Deficient Olefins

“…For details, see the Supporting Information). Owing to the unique properties of the trifluoromethyl unit in promoting the metabolic stability and bioavailability of many bioactive compounds [62,63], several CF 3 -containing heterocyclic compounds, in particular of trifluoromethyl-substituted pyrrolidines, have been synthesized with [3 + 2] cycloaddition reaction in the past few years [64][65][66][67][68]. To expand the application of benzothiazolium salts in constructing spiro-pyrrolidines, the [3 + 2] cycloaddition between benzothiazolium salts and 3-trifluoroethylidene oxindoles was conducted.…”