Efficient Oxidative Dehydrogenation of N-Heterocycles over Nitrogen-Doped Carbon-Supported Cobalt Nanoparticles

Catalytic oxidative dehydrogenation of N-heterocyclic compounds has been considered to be an important route to access heteroarenes. In this study, a heterogeneous catalyst by the loading of cobalt nanoparticles on the nitrogen-doped carbon support (Co/MC) was prepared and studied for the oxidation of N-heterocyclic compounds with O2. A variety of reaction parameters were optimized for this transformation, and quinolines with yields from 84.9% to 98.8% were achieved by the oxidation of N-heterocycles at 150 °C under 2.5 bar O2. The oxidation of N-heterocycles underwent via superoxide radical anions (•O2–) as the active species. More importantly, the Co/MC catalyst can be reused and kept its activity. This method provides an environmentally friendly and economical route for the preparation of heteroarenes via the oxidative dehydration of N-heterocyclic compounds.