Speedy and clean hypervalent iodine/nitroxyl radical mediated oxidation of alcohols using recyclable adamantane reagent with highly active 2-azaadamantane-N-oxyl organocatalyst.

By utilizing a specific solvent and highly active 2-azaadamantane-N-oxyl (AZADO) as an organocatalyst, we have improved the recycling protocol of the adamatane reagent 1 to be faster and more operationally simple for the hypervalent iodine/nitroxyl radical mediated alcohol oxidation. This very mild system can efficiently mediate the oxidation of a range of alcohols to carbonyl compounds with a broad substrate scope, and after the reactions, the reduced adamantane tetraiodide 1', which automatically precipitated from the reaction mixtures as the reactions progresses, could be directly recovered by filtration.