Electrochemical C─H Amination From a Primary Amine via a Cobalt Nitrene Intermediate

Metal nitrene transfer catalysis is an efficient method for the direct formation of C─N bonds, but currently requires prefunctionalized, hazardous nitrene precursors. To expand the use of metal nitrene transfer catalysis, a method that generates the desired metal nitrene intermediate from an unfunctionalized nitrogen source is imperative. In this work, we demonstrate that a cobalt nitrene intermediate can be generated from 4‐phenylbutylamine under electrochemically oxidative conditions, supported by electron paramagnetic resonance (EPR) and high‐resolution mass spectrometry (HR‐MS) measurements. Constant potential electrolysis allowed C─H amination of 4‐phenylbutylamine to 2‐phenylpyrroline, a cyclic imine, formed via oxidation of 2‐phenylpyrrolidine. This method provides proof of principle to unlock the use of unfunctionalized amines as nitrene precursor alternatives, thereby extending the applicability of metal nitrene transfer catalysis .