A NOVEL OXIDIZING REAGENT BASED ON POTASSIUM FERRATE(VI)

A new, efficient preparation has been devised for potassium ferrate(VI )(K2FeO4). The ability of this high-valent iron salt for oxidizing org anic substrates in nonaqueous media was studied. Using benzyl alcohol as a model, the catalytic activity of a wide range of microporous adso rbents was ascertained. Among numerous solid supports of the aluminosi licate type, the K10 montmorillonite clay was found to be best at achi eving quantitative formation of benzaldehyde, without any overoxidatio n to benzoic acid, The roles of the various parameters (reaction time and temperature, nature of the solvent, method of preparation of the s olid reagent) were investigated. The evidence points to a polar reacti on mechanism. The ensuing procedure was applied successfully, at room temperature, to oxidation of a series of alcohols to aldehydes and ket ones, to oxidative coupling of thiols to disulfides, and to oxidation of nitrogen derivatives. At 75 degrees C, the reagent has the capabili ty of oxidizing both activated and nonactivated hydrocarbons. Toluene is turned into benzyl alcohol (and benzaldehyde), Cycloalkanes are als o oxidized, in significant (30-40%) yields, to the respective cycloalk anols (and cycloalkanones). Thus, potassium ferrate, used in conjuncti on with an appropriate heterogeneous catalyst, is a strong and environ mentally friendly oxidant.