Catalyst- and Solvent-Free Aerobic Oxidative Coupling of Amines to Imines: Revisiting a Misunderstood Transformation

The synthesis of imines is a fundamental transformation in organic chemistry. Despite its significance, the development of efficient protocols that eliminate the need for catalysts and solvents has remained a longstanding challenge. In this study, we report a catalyst-, additive-, and solvent-free method for imine synthesis via aerobic oxidative coupling of amines. This atom-economical, environmentally benign process eliminates solvent-related waste and challenges the traditional reliance on catalysts, offering mechanistic insight into the intrinsic reactivity of aerobic amine coupling.