Probing the effect of nitrate anion in CAN: An additional opportunity to reduce the catalyst loading for aerobic oxidations

Catalyzed by cerium ammonium nitrate (CAN), the oxidative cracking reaction of alkenes occurred to produce carbonyls in good yields under mild conditions. The reaction employed molecular oxygen (O2) as the safe and clean oxidant. The catalyst dosage was reduced to as low as 0.5 mol%, while no additive was required. Thus, it may afford a generally green synthetic approach for introducing oxygen into organic molecules as well as the biomass degradation and the resource recycling from the C=C bond-containing waste polymers. X-ray photoelectron spectroscopy (XPS) analysis and control experiments demonstrated that the process proceeded via a single electron transfer (SET) reaction-initiated free radical reaction mechanism. In the process, both Ce and NO3− acted as the oxygen carrier to promote the oxidation reaction. The application of the abundantly existed nitrate in CAN was found to be the key for reducing the catalyst loading.