Ionic liquids improve citronellyl ester synthesis catalyzed by immobilized Candida antarctica lipase B in solvent-free media

Several citronellyl esters ( acetate, propionate, butyrate, caprate and laurate) were synthesized by immobilized Candida antarctica lipase B ( Novozym) in high yields (> 99%) using equimolar mixtures of citronellol and alkyl vinyl ester as substrates in solvent-free medium. The best results were obtained for citronellyl butyrate synthesis (17.4 mu mol min(-1) mg IME-1) at 70 degrees C, which could be improved up to two-fold by coating the biocatalyst particles with alkyl imidazolium-based ionic liquids, which favoured partitioning of the substrate and product molecules.