The effect of the migrating group structure on enantioselectivity in lipase-catalyzed kinetic resolution of 1-phenylethanol.

We have studied the effects of the acyl moiety on the enantioselectivity of three lipases: Candida antarctica B , Pseudomonas cepacia and Candida cylindracea , frequently used in kinetic resolutions by acylation or hydrolysis. The size of the acyl group was examined using various enol esters during the transesterification of 1-phenylethanol and the hydrolysis of the corresponding phenylethylesters. C. antarctica-B lipase showed the highest selectivity in the transesterification of 1-phenylethanol with isopropenyl and vinyl acetate, vinyl decanoate, vinyl laurate, ( E > 200). The esters 1-phenyl -ethyl-acetate, decanoate and laurate are also hydrolyzed with high selectivities ( E > 150) with CAL-B. The results can be correlated to the three-dimensional form of each lipase. The effect of the migrating group on the reactivity and selectivity of the lipases are discussed for both reactions. [ABSTRACT FROM AUTHOR]