Kinetic resolution of racemic alcohols catalyzed by minimal artificial acylases derived from L-histidine

The artificial acylases, tert-butyldiphenylsilyl ether and tris(trimethylsilyl) silyl ether of N(pi)-methyl-N(alpha)-(2,4,6-triisopropyl-benzenesulfonyl)-L- histidinol, are simple and small molecules, which contain only one chiral carbon center that originates from natural L-histidine. Asymmetric acylation of racemic secondary alcohols with isobutyric anhydride induced by these artificial acylases gave optically active isobutyrates and optically active alcohols with an S(k(fast-reacting enantiomer)/k(slow-reacting enantiomer)) value of up to 132. One hydrogen bonding interaction between a sulfonamidyl group of the catalysts and a substrate should be essential for inducing the high level of kinetic resolution through catalytic asymmetric acylation. Furthermore, a reusable polystyrene-bound artificial acylase was developed to examine its practicality. (c) 2007 Elsevier Ltd. All rights reserved.