The Separation Of Chiral α-Trifluoromethyl Aryl Alcohols By HPLC And Kinetic Resolution Cyanohydrins

Kinetic resolution (KR) is a powerful means for the preparation of enantiomerically pure compounds. KR of secondary alcohols catalyzed by acyl transfer organocatalysts has made remarkable progress.Synthesis of chiral fluoroorganic compounds is important in chemistry in view of the unique biological and mechanical properties imparted by fluorine atom to the molecules. In the study of kinetic resolution of a series of 2,2,2-trifluoro-1-aryl ethanols, the e. e. value of the products were tested by HPLC(OJ-H or OD-H) after optimization of testing conditions ( including the composition of flowing phase, the temperature, flowing rate, etc.).Enantiomerically pure (or enriched) cyanohydrins are versatile synthetic intermediates as they bear a hydroxyl group and a cyano group on one chiral carbon. They therefore provide a wide space for transformation into a large number of chiral molecules, which are important in the synthesis of biologically active molecules.A enzyme catalyzed kinetic resolution system was established after screening several kinds of lipases and optimization the reaction conditions, in which by using lipase PS-30 as catalyst, Vinyl acetate and Ether were the preferred acyl donor and solvent. The reaction rate was slowed down with the addition of water . When the reaction was carried out under the above optimum conditions, the conversion of mandelonitrile was 42 % and e.e. was 98%, after 24 h.the kinetic resolution of a series of racemic cyanohydrins has been achieved via enantioselective acylation.