Dosage delivery of chiral ruthenium catalysts using non-ionic surfactants for asymmetric transfer hydrogenation reactions in aqueous media

Abstract

In this study, non-ionic surfactants, namely Synperonic®F108 and Tween®F108, were used as media to dissolve [RuCl(p-cymene)(R,R)-Ts-DPEN] for the dosage delivery and recycling of chiral ruthenium catalysts in asymmetric transfer hydrogenation reactions of ketones in water. The non-ionic surfactant-based catalytic systems bearing ruthenium catalysts in microgram scale can be used directly to conduct transfer hydrogenation reactions in nano-sized micelle structures (60–90 nm) in water under an air atmosphere. The micellar catalyst in the aqueous phase can be recycled from the reaction mixture and can be used up to 8 times in asymmetric transfer hydrogenation reactions of acetophenone.