Enantioselective Hydrogenation of Simple Ketones

Enantioselective reduction of prochiral ketones to optically active secondary alcohols is an important, fundamental subject in synthetic organic chemistry, because the resulting chiral alcohols are versatile building blocks for synthesis of natural or unnatural biological active compounds as well as functional materials. Asymmetric hydrogenation is particularly useful for a large-scale reduction because of the operational simplicity, economical advantage, and environmental consciousness. Enantioselective hydrogenation of simple ketones which have no heteroatoms near carbonyl groups has remained difficult. This review describes the recent development in this area. Certain chiral Ru (II) complexes exhibit an excellent catalytic activity and enantiodifferentiation ability in asymmetric hydrogenation of simple ketones in homogeneous phase.