Asymmetric Cycloaddition of N-2,2,2-Trifluoroethylisatin Ketimines and Unsymmetrical Dicarbonyl-Activated Alkenes: Construction of 5'-Trifluoromethylated 3,2'-Pyrrolidinyl Spirooxindoles with Three Carbonyl Groups

J Org Chem. 2024 Sep 20;89(18):12924-12934. doi: 10.1021/acs.joc.4c00805. Epub 2024 Aug 28.

Abstract

The asymmetric cycloaddition between N-2,2,2-trifluoroethylisatin ketimines and unsymmetrical dicarbonyl-activated alkenes catalyzed by a bifunctional squaramide has been discovered. The present study demonstrates an efficient approach for the regio-, diastereo-, and enantioselective synthesis of densely functionalized 5'-trifluoromethylated 3,2'-pyrrolidinyl spirooxindoles featuring three different types of carbonyl groups.