Studies On The Nitroxyl Radicals-catalyzed Selective Oxidation Of Alcohols

Simple, mild, efficient and high selective methods for nitroxyl radical-catalysed alcohol oxidation were developed in the paper.Initial experiment showed that TEMPO/FeCl₃ can catalyze the selective, quantitative aerobic oxidation of alcohols in the presence of NaNO₂. The effect of various conditions (such as solvent, counterion, temperature, oxygen pressure and so on) on the reaction was studied. Under optimum condition, TEMPO/FeCl₃/NaNO₂ catalysed the selective and mild aerobic oxidation of a broad range of alcohols, which may bear N and S heteroatoms or carbon–carbon double bond, to the corresponding aldehydes and ketones with high yield. On the base of experiments, the roles of TEMPO, NaNO₂ and Fe were confirmed and a plausible mechanism was proposed.Instead of Fe, TEMPO/Cu/NaNO₂ and TEMPO/Cr/NaNO₂ can also catalyze the selective aerobic oxidation of alcohols. Similarly, the effect of various conditions (such as solvent, counterion, temperature, oxygen pressure and so on) on the reaction was studied. PEG-supported TEMPO was successfully used as a catalyst for the oxidation of benzylic alcohol in the presence of TEMPO/FeCl₃. Forthermore, we investigated the recycleability of the catalyst.Alcohols were oxidized to corresponding aldehydes and ketones in the presence of catalytic amount of N–Hydroxysuccinimide with...