Recent Advances in the Development of Chiral Metal Catalysts for the Asymmetric Hydrogenation of Ketones

This review describes recent advances in the development of chiral metal catalysts for the asymmetric hydrogenation of ketones to give chiral alcohols, important building blocks for biologically active substances such as pharmaceuticals and natural products. Chiral ruthenium–diphosphine/diamine complexes have received intensive study and many efficient chiral ruthenium catalysts bearing chiral diphosphine and diamine ligands have been developed over the past few decades. In addition, chiral ruthenium, iridium, osmium, iron, copper, and palladium complexes with various chiral ligands have also emerged as highly efficient chiral metal catalysts for the asymmetric hydrogenation of ketones. A wide range of ketones are hydrogenated using these chiral metal catalysts to give chiral alcohols with excellent enantioselectivity with high turnover numbers (TONs) and turnover frequencies (TOFs). 1 Introduction 2 Chiral Ruthenium Catalysts 3 Chiral Iridium Catalysts 4 Other Chiral Metal Catalysts 5 Conclusion and Outlook