Highly Diastereoselective Formation of Ruthenium Complexes for Efficient Catalytic Asymmetric Transfer Hydrogenation

Abstract

Jumping Josiphos! Ruthenium cis-dichloro complexes with matched chiral diphosphane and aminopyridine ligands (see structure) are easily obtained by a one-pot reaction of [RuCl2(PPh3)3] with a Josiphos diphosphane and racemic 1-substituted 1-(pyridin-2-yl)methanamine ligands. These complexes are highly active catalysts for the transfer hydrogenation of ketones, affording turnover frequencies of up to 70 000 h−1 at 60 °C and ee values up to 99 %.