Importance of Product Desorption in Enantioselective Hydrogenation of (E)-(alpha)Phenylcinnamic Acid with a Cinchonidine-Modified Pd/TiO2 Catalyst: Effect of Additives

Addition of amines, especially benzylamine, to the reaction mixture of (E)-(alpha)-phenylcinnamic acid with a cinchonidinemodified palladium catalyst resulted in much enhanced activities and fairly increased enantioselectivities. The preferential acceleration of the selective reaction is attributable to the effective desorption, assisted by the added base, of the hydrogenated molecules from the modified sites.