Synthesis of chiral epichlorohydrin by chloroperoxidase-catalyzed epoxidation of 3-chloropropene in the presence of an ionic liquid as co-solvent

Asymmetric epoxidation of 3-chloropropene can be catalyzed by chloroperoxidase (CPO) from Caldariomyces fumago to prepare (R)-epichlorohydrin (ECH) in homogenous phosphate buffer/ionic liquid mixtures using t-butyl hydroperoxide (TBHP) as O2 donor.Reaction conditions were optimized by the investigation of the choice of oxidants, the presence of ionic liquids (ILs), pH effect and CPO consumption. The best ECH yield reached 88.8% within a duration of 60 min with high enantiomeric excesses (e.e. 97.1%) at pH 5.5 and room temperature, using 1-ethyl-3-methylimidazolium [EMIM][Br] as co-solvent. The ILs with shorter carbon chain was more efficient on chiral ECH preparation.