resumo
The complex IndMo(CO)(3)Me (Ind = eta(5)-C9H7) is an effective catalyst precursor for the epoxidation of DL-limonene using the following oxidant solutions: (i) commercial tert-butylhydroperoxide in decane (TBHPdec), (ii) commercial aqueous TBHP (TBHPaq) pre-mixed with limonene (TBHP_lim), or (iii) TBHPaq pre-mixed with 1,2-dichloroethane (TBHPdce); simple pre-drying treatments of the reaction solutions were applied prior to feeding the catalyst precursor to the batch reactor. The best results were found for the efficiently pre-dried reaction system (iii), which gave higher 1,2-epoxy-p-meth-8-ene yield at 35 min/55 degrees C than (i) (82% and 73% yield, respectively). This approach avoids the undesirable partial oxidation of decane, which would imply costly work-up procedures to remove high boiling point impurities from the epoxides. These results together with studies on the reactivity of different olefins indicate fairly high regioselectivity toward the epoxidation of the internal double bonds. (C) 2011 Elsevier B.V. All rights reserved.
palavras-chave
OLEFIN EPOXIDATION; TUNGSTEN COMPLEXES; ETA(5)-CYCLOPENTADIENYL MOLYBDENUM; CYCLOALKYL MOIETIES; CRYSTAL-STRUCTURES; BRIDGING UNITS; ANSA COMPOUNDS; OXIDATION; DERIVATIVES; REACTIVITY
categoria
Chemistry
autores
Abrantes, M; Bruno, SM; Tome, C; Pillinger, M; Goncalves, IS; Valente, AA
nossos autores
Anabela Tavares Aguiar Valente
Investigador Principal
Isabel Maria de Sousa Gonçalves
Professor associado
Martyn Pillinger
Investigador Principal