RUTHENIUM-CATALYZED OXIDATION OF PRIMARY ALCOHOLS WITH THE NEW OXIDATION SYSTEM N-METHYLMORPHOLINE/HYDROGEN-PEROXIDE

Long chain alcohols such as octanol, dodecanol and hexadecanols are oxidized to the corresponding aldehydes and carboxylic acids in the presence of the homogeneous catalyst tris(triphenylphospine) ruthenium dichloride. The known oxidizing agent N-methylmorpholine N-oxide (MMO) has been compared with a new system involving N-methylmorpholine (MM) and hydrogen peroxide. With the system MM/H2O2 simple recycling of the ruthenium catalyst and of the oxygen transmitter MM is possible by a simple phase separation process. A mechanism is proposed in which the oxygen of the MMO formed in situ serves to convert a dihydrido-ruthenium complex into the catalytically active ruthenium species.