Oxidation of saturated hydrocarbons catalyzed by metal porphyrin complexes

Abstract

The present developed oxidation of saturated hydrocarbons could beperformed at room temperature and atmospheric pressure using metalporphyrin complex as a catalyst, zinc grit/air as an oxidant in apyridine-acetic acid media. Ketone was obtained as a major productselectively. From the screening for appropriate metalloporphyrin, Fe(II)-porphyrin complex provided the best result. The variation of thesubstituent on a phenyl ring revealed thattetra(3,4,5-trimethoxyphenyl)-porphyrin iron (II) complex was the promisingcatalyst in this developed system. Chemoselectivity study disclosed thatadditives in this system affected ketone/alcohol ratio and the amount ofthe desired products. From chemical evidence, possibly alkyl hydroperoxidewas an intermediate of the reaction and believed not to take place ~ivia~iradical pathway. In addition, regioselectivity study on the oxidation ofl~iert~i-butylcyclohexane and ~in~i-pentane exhibited that the oxidationreaction under this particular condition occurred more selectively compared withthat using TBHP as an oxidant.