Alcohol Oxidation Catalyst Showing Higher Activity than TEMPO

Recently, environmentally friendly oxidation catalyzed by TEMPO, a nitroxy radical, has been attracting attention. Iwabuchi et al. have reported highly efficient oxidation of alcohols catalyzed by 2-azaadamantan-N-oxyl (AZADO), a nitroxy radical.^1,2,3) AZADO exhibits a higher oxidation ability than TEMPO, which allows it to oxidize even hindered secondary alcohols in high yields. 2-Hydroxy-2-azaadamantane (AZADOL®), developed by Iwabuchi et al., is a more storage-stable catalyst than AZADO. AZADOL® shows the same performance because of having a catalytic reaction mechanism via AZADO in the presence of oxidants. Other oxidation by oxoammonium salts derived from AZADOL® has been also investigated.⁴⁾