Clean and selective oxidation of alcohols with n-Bu4NHSO5 catalyzed by ionic liquid immobilized TEMPO in ionic liquid [bmim][PF6]

An efficient oxidation of alcohols with tetra-n-butylammonium peroxymonosulfate catalyzed by ionic liquid immobilized TEMPO in ionic liquid [bmim][PF6] was reported. TEMPO-IL serves as a homogeneous catalyst to enhance the reaction remarkably. The oxidation proceeded to afford aldehydes or ketones in excellent yields and high selectivity without remarkable over-oxidation to carboxylic acids. It is noteworthy to mention that the catalyst and solvent could easily be recycled and reused without loss of activity. A possible mechanism for the oxidation is proposed.