Aerobic oxidation of alcohols enabled by nitrogen-doped copper nanoparticle catalysts

Heterogeneous nitrogen-doped carbon-incarcerated copper nanoparticle catalysts have been developed. The catalysts promoted the oxidation of alcohols to the corresponding aldehydes, including aliphatic substrates, in high yield in the presence of an N-oxyl radical co-catalyst. The catalysts were applied to a flow reaction and a long lifetime (up to >5 days) was achieved by tuning the flow rate of oxygen gas. By applying the catalysts, two-step, sequential, continuous-flow synthesis of unsaturated carbonyl compounds was demonstrated, and the product was further converted into a bioactive heterocycle without isolation of intermediates.