Catalytic epoxidation of cyclohexene using Molybdenum complexes

• J. A. Gnecco ^[1] ; G. Borda ^[1] ; P. Reyes ^[1]
  1. [1] Universidad de Concepción

     Universidad de Concepción

     Comuna de Concepción, Chile

     
• Localización: Journal of the Chilean Chemical Society (Boletín de la Sociedad Chilena de Química), ISSN-e 0717-6309, ISSN 0366-1644, Vol. 49, Nº. 2, 2004, págs. 179-184
• Idioma: inglés
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• Resumen

  • Three oxomolybdenum complexes, MoO2(acac)2, MoO2(oxine)2 and MoO2(PDTC)2, were prepared, characterised and essayed as catalysts for the epoxidation of cyclohexene in a batch reactor. The reaction was performed at 60 and 70°C using tert-butylhydroperoxide as oxidant agent and toluene and dichloroethane as solvents. All the complexes exhibit high selectivity to the corresponding epoxide under the studied conditions, being the MoO2(acac)2 the one that exhibits the highest specific rate constant. An enhancement in the specific rate constant is observed at higher reaction temperatures and by using dichloroethane as solvent. A detailed kinetic study showed that the cyclohexene epoxidation is a global second order reaction: order one with respect to cyclohexene and also order one dependence in tert-butylhydroperoxide. A reaction mechanism that explains the experimental results is proposed