- Epoxidation and Baeyer-Villiger oxidation using hydrogen peroxide and a lipase dissolved in ionic liquids
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Epoxidation and Baeyer-Villiger oxidation of olefins and (cyclic) ketones were successfully carried out in hydrogen-bond-donating (HBD) ionic liquids, using a lipase-catalysed cascade and hydrogen peroxide as the terminal oxidant. The effect of the ionic liquids turned out to be twofold. The HBD ionic liquids exhibited a substantial positive solvent effect on the second step of the cascade, namely the oxygen transfer by peracid. In addition, we found that the Candida antarctica B lipase (CaLB) dissolved in 1-(3-hydroxypropyl)-3-methyl imidazolium nitrate 1a and 1-butyl-3-methylimidazolium nitrate 2a. This stable enzyme-ionic liquid solution opens the possibility for continuous chemical processing.
- Kotlewska, Aleksandra J.,Van Rantwijk, Fred,Sheldon, Roger A.,Arends, Isabel W.C.E.
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experimental part
p. 2154 - 2160
(2011/10/09)
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- Tris(2-hydroxyethyl)ammonium salts: 2,8,9-Trihydroprotatranes
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New method of synthesis of tris(2-hydroxyethyl)ammonium salts, 2,8,9-trihydroprotatranes X-[HN(CH2CH2OH) 3]+, based on the reaction of tris(2-hydroxyethyl)amine (triethanolamine) with ammonium salts NH4X (X = F, Cl, Br, I, NO 3, ClO4) was developed. 1H, 13C, 15N NMR and IR spectra of these protatranes were investigated, as well as those of their analogs with X = RCH2COO (R = H; 2-MeC 6H4O; 2-Me-4ClC6H3O; 2-MeC 6H4S; 4-ClC6H4S; 4-ClC 6H4SO2; 3-IndS; 3-(PhCH2-IndS) prepared from the corresponding acids RCH2COOH and triethanolamine. The parameters of IR and NMR spectra of the studied protatranes were governed by the nature of substituent X, which also determined the character of the intra and intermolecular hydrogen bonds NH...O and OH...O in the protatrane framework.
- Voronkov,Albanov,Aksamentova,Adamovich,Chipanina,Mirskov,Kochina,Vrazhnov,Litvinov
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experimental part
p. 2339 - 2346
(2010/05/15)
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