Organocatalytic Enantioselective Michael Addition of 3‐Indolinone‐2‐Carboxylates to Maleimides

Abstract

An organocatalyzed asymmetric conjugate addition of 2‐substituted 3‐indolinones to maleimides has been developed by using a chiral bifunctional squaramide derived from quinidine to promote the reaction. This method provides easy access to 3‐indolinone‐2‐carboxylate‐succinimide adducts in high yields with excellent diastero and entantioselectivities and is a useful approach for the construction of vicinal quaternary‐tertiary chiral centers. In addition, product 4l was successfully converted into a chiral indoline‐pyrrolidine adduct.