Dipl.-Chem. Johannes Schäffer
- Ionic liquids (ILs) in catalysis
- Micellar-catalytic epoxidation of cyclooctene using ionic liquids
Epoxidation is an important step in the valorisation of olefins since epoxides are highly useful as intermediates for the manufacture of high-value industrial products. In industry, not only ethylene oxide and propylene oxide, but also epoxides derived from longer-chain olefins are of interest, e.g. as reactive diluents, plasticisers or as reactants for fine chemicals production . During epoxidation of these olefins, H2O2, which is a commonly employed oxidant, is in the aqueous phase while the hydrophobic olefins form a second organic phase. The low solubility of olefins in the aqueous phase and that of the oxidant in the organic phase limit the overall reactivity. Thus the choice of an appropriate catalytic and solvent system is crucial to attain satisfactory catalytic activity. Phase transfer catalysis is a conventional approach to tackle this issue [2, 3]. Alternatively, micellar catalytic systems that improve catalyst or substrate solubility by micelle formation in the aqueous phase can lead to higher catalytic activity . In 2013, Markovits et al. reported for the first time that the catalytically inactive perrhenate anion gains largely in activity for epoxidation of cyclooctene with hydrogen peroxide when used as anion in an imidazolium-based ionic liquid [5, 6]. Our focus is on the mechanistic and kinetic description of the perrhenate-catalysed epoxidation and on its possible industrial implementation.
 G. Sienel, R. Rieth, K. Rowbottom: Epoxides, in: Ullmann’s Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2012.
 E. V. Dehmlow, S. S. Dehmlow, Phase Transfer Catalysis, Wiley-VCH, Weinheim, 1993.
 S.-S. Wang, G.-Y. Yang, Chem. Rev. 2015, 115, 4893-4962.
 J. H. M. Heijnen et al., Chem. Eng. Proc. 2003, 42, 223-230.
 I. I. E. Markovits et al., Chem. Eur. J. 2013, 19, 5972-5979.
 M. Cokoja et al., ChemSusChem 2016, 9, 1773-1776.
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