Methane Catalytic Amidation via a Plausible Copper-Nitrene Intermediate

The catalytic conversion of CH₄ into CH₃X compounds has been reported in a few cases, usually involving dehydrogenative processes in which the H atom is lost. Aiming at expanding this limited set of transformations, we have investigated the methane amidation reaction through metal-catalyzed nitrene transfer reactions, a transformation that remains unreported to date for the lightest hydrocarbon. Herein, we describe the use of copper-based catalysts for the direct, nondehydrogenative amidation reaction of methane via a metal-mediated formal nitrene insertion into the C-H bond, a reaction that is also extended to the series of gaseous alkanes. Mechanistic studies, supported by DFT calculations, a microkinetic model, and experimental evidence have led to the proposal of a metallonitrene intermediate responsible for this C-H amidation process via sequential hydrogen abstraction and rebound steps.