resumo
Following our approach on the use of metalloporphyrins as catalysts and hydrogen peroxide as oxidant in the oxidation of organosulfur compounds (e.g. sulfides, benzothiophenes and dibenzothiophenes), herein the excellent catalytic performance of a homogeneous iron(III) porphyrin complex is demonstrated. Beyond the better results obtained, when compared with those with manganese(III) complexes, the present procedure involves a cleaner approach because ethanol is used as solvent and a co-catalyst is not required. For all the studied substrates (1-10), conversions higher than 95% were achieved with Fe(TF4NMe2PP)Cl (I). More significantly, catalyst (I) is also efficient in the oxidation of a model fuel, constituted by a mixture of benzothiophene (3), 3-methylbenzothiophene (5), 4-methyldibenzothiophene (8) and 4,6-diethyldibenzothiophene (10) in hexane, affording an overall conversion of 84%. (C) 2014 Elsevier B.V. All rights reserved.
palavras-chave
HYDROGEN-PEROXIDE; MANGANESE(III) PORPHYRINS; AMMONIUM ACETATE; DESULFURIZATION; METALLOPORPHYRINS; EPOXIDATION; SULFOXIDES; CHEMISTRY; CATALYSTS; SULFIDES
categoria
Chemistry; Engineering
autores
Pires, SMG; Simoes, MMQ; Santos, ICMS; Rebelo, SLH; Paz, FAA; Neves, MGPMS; Cavaleiro, JAS
nossos autores
agradecimentos
We would like to thank Fundacao para a Ciencia e a Tecnologia (FCT, Portugal), the European Union, QREN, FEDER, COMPETE, for funding the Organic Chemistry Research Unit (QOPNA) (PEst-C/QUI/UI0062/2013) and CICECO (PEst-C/CTM/LA0011/2013). Authors also acknowledge the Portuguese National NMR Network, supported with funds from FCT. S.L.H. Rebelo thanks project NORTE-07-0124-FEDER-000067-nanochemistry for her grant. S.M.G. Pires also thanks FCT for her PhD Grant (SFRH/BD/64354/2009) and F.A.A. Paz would like to thank FCT for the financial support towards the purchase of the single-crystal diffractometer.