Kinetics and mechanism of the oxidation of alkyl substituted phenols and naphthols with tBuOOH in the presence of supported iron phthalocyanine

摘要: 2,3,5-Trimethylbenzoquinone (precursor of vitamin E) and 2-methylnaphthoquinone (vitamin K3) were obtained in good yields by oxidation 2,3,6-trimethylphenol 2-methyl-1-naphthol, respectively, with tBuOOH catalyzed supported iron tetrasulfophthalocyanine. The mechanism this heterogeneous was studied using 18O2labeling experiments, EPR spectroscopy spin traps, kinetic studies, complete analysis reaction products including minor ones. experiments did not indicate the involvement O2 oxidative process. study mixtures 2-methyl-1-naphthol oxidations presence 3,5-dibromo-4-nitrosobenzenesulfonic acid trap showed no formation any radical intermediates. Besides target quinones, epoxyquinones formyldimethyl-1,4-benzoquinones, as over-oxidation have been found. C–C C–O coupling relevant to one-electron pathways detected trace amounts. Based on experimental results, a alkyl-substituted phenols naphthols mediated phthalocyanine catalyst has proposed which involves two successive electron transfers without escape species solution.