Recyclable MeOPEG-clicked TEMPO catalyst for one-pot aerobic double dehydrogenation of alcohols to nitriles

Abstract

In this study, TEMPO was efficiently grafted on MeOPEG support by copper-catalyzed (3 + 2) cycloaddition reaction. The newly immobilized MeOPEG-clicked TEMPO catalyst was characterized by NMR, IR, and MALDI-TOF. Subsequently, it was used for one-pot aerobic double dehydrogenation of alcohols to nitriles using aqueous ammonia as the nitrogen source and O2 (1 atm) as the terminal oxidant. The catalytic efficiency was also reported with various benzyl, alkyl, and heteroaromatic alcohols. The reactivity of this catalyst is comparable with that of unmodified TEMPO. Furthermore, the new MeOPEG-clicked TEMPO catalyst could be easily recovered by precipitation and recycled up to five runs.