Research Advances of the Chiral Binap-Ru(II) Catalysts in Asymmetric Hydrogenation Reactions

Chiral 2,2'-bis(diphenylphosphino)-1,1'-binapthyl (Binap) ligand consists of a pair of 2-diphenylphosphinonaphthyl groups connected at the 1 and 1' positions, being of the nature of the C-2-axial chirality with optical activity of +/- 234 degrees. The Binap can coordinate with many transitional metals to form stable chelation complexes, effecting the chirality transfer to the metal center for function in asymmetrically catalytic reactions. This contribution is focused on the Binap-Ru(II) catalytic system that covers the various substrates, reaction conditions, enantioselectivity of the products, reaction mechanism, and others on the basis of the prepared stable Binap-Ru(II) complexes as the clue in the text. This study will give a deep understanding of this system especially concerning the applied catalytic synthesis of the useful organic molecules.