Anaerobic oxidation of metal carbenoids

Herein we report anaerobic oxidation of metal carbenoids generated from aryl diazo esters under ball milling with heterocyclic N-oxide in the presence of catalytic copper(I) to afford 1,2-dicarbonyls in excellent yield. Efficiently progressing across a diverse spectrum of substrates, the reaction demonstrates exceptional tolerance to a variety of functional groups, under mild reaction conditions, at low catalyst loading and minimum volume of solvent as a Liquid-Assisted Grinding (LAG) auxiliary thereby demonstrating a practical strategy to generate these molecules.