Cu/PCy₃‐Catalyzed Formal Carbene Insertion into Electron‐Deficient C−H Bonds

Abstract

Abstract A carbene insertion into electron‐deficient C−H bonds of 1,3‐diesters, β‐ketoesters, β‐ketonitriles, and malononitriles was realized by using CuCN/PCy 3 as the catalyst. The reaction provides a straightforward approach to the synthetically important multi‐substituted succinic acid derivatives. A plausible reaction mechanism with cyclopropanation/ring opening as key steps was proposed based on control experiments.