Conversion Dependence of Enantioselective Hydrogenation of (<i>E</i>)-<i>α</i>-Phenylcinnamic Acid on Cinchonidine-Modified Pd/TiO2 Catalyst

Abstract

Abstract The enantioselectivity of a cinchonidine-modified Pd/TiO2 catalyst varied with the extent of conversion in the hydrogenation of (E)-α-phenylcinnamic acid. The incremental enantioselectivity reached a maximum at an early stage of the reaction. Under optimized reaction conditions, optical yields of up to 72 %e.e. of (S)-(+)-2,3-diphenylpropionic acid were obtained at 100 % conversion.