Journal of Chemical Technology and Biotechnology, Vol.84, No.7, 1051-1055, 2009
Fluorous biphase oxidation of ethyl benzene and benzyl alcohol catalyzed by perfluoroalkyl phthalocyanine complexes
BACKGROUND: Ketones and aldehydes are important organic chemicals as intermediates for the pharmaceutical and fine-chemical industries. The existing oxidation reactions to obtain ketones and aldehydes are no longer sustainable because of the large amount of waste generated and use of stoichiometric reagents: a cleaner catalytic oxidation system needs to be developed. RESULTS: The experimental results show that cobalt (II) tetra-(perfluorohexyl) phthalocyaninate delivered a high catalytic activity for the oxidation of ethyl benzene (35% conversion and 86% selectivity to acetophenone) at 90 degrees C under ambient pressure of oxygen. The catalyst could be recycled for at least four runs. For the oxidation of benzyl alcohol to benzaldehyde, a conversion of 6% was achieved but with a selectivity of 100% at 90 degrees C under 2 x 10(5) Pa O-2. CONCLUSION: Perfluoroalkyl metallophthalocyanines can be used for the fluorous biphasic oxidation of ethyl benzene and benzyl alcohol with molecular oxygen. The cobalt (II) tetra-(perfluorohexyl) phthalocyaninate exhibited the highest catalytic activity for the oxidation of ethyl benzene. The catalytic oxidation of benzyl alcohol using our method may be feasible in industrial applications. (C) 2009 Society of Chemical Industry
Keywords:perfluoroalkyl phthalocyanines;fluorous biphasic catalysis;oxidation;ethyl benzene;benzyl alcohol