Organocatalytic Enantioselective Amination of 2-Substituted Indolin-3-ones: A Strategy for the Synthesis of Chiral α-Hydrazino Esters.

An efficient enantioselective α-amination of 2-substituted 3-indolinones has been achieved for the first time using hydroquinidine as a chiral catalyst through an aza-Michael reaction. The desired α-hydrazino esters are obtained in excellent yields with high enantiomeric excess leading to a quaternary stereocenter with a broad substrate scope.