Activation of Lipase by Chiral Imidazolium Cetyl-PEG10-Sulfate

Significance

The chiral pyrrolidine-substituted imidazolium cetyl-PEG10-sulfate (d-ProMe, 3a) was prepared as an activating agent of Burkholderia cepacia lipase (lipase PS). Thus, the ion exchange reaction of chiral pyrrolidine-substituted imidazolium bromides 1a,b with 2 (1.0 equiv) gave the corresponding imidazolium cetyl-PEG10-sulfate 3a,b (eq. 1). Coating treatment of lipase PS with 3a by the lyophilization process afforded the coated enzyme d-ProMe-PS (eq. 2). Transesterification of ()-1-phenylethanol (4) with vinyl acetate (1.5 equiv) was carried out in the presence of d-ProMe-PS to afford a mixture of (R)-5 (37% yield, >99% ee) and unreacted (S)-4 (39% yield, 97% ee) (eq. 3).