The development of phosphine-free "tethered" ruthenium(II) catalysts for the asymmetric reduction of ketones and imines

In this account, we describe the design, synthesis and applications of tethered versions of the Ru(II)/N‐tosyl‐1,2‐diphenylethylene‐1,2‐diamine (TsDPEN) class of catalyst that are commonly used for asymmetric transfer hydrogenation and asymmetric hydrogenation of ketones and imines. The review covers key aspects of the reaction mechanisms and examples of applications, including industrial applications to pharmaceutically important target molecules. In addition, closely related catalysts based on Rh(III) and Ir(III) are also described

pH-Independent Transfer Hydrogenation in Water: Catalytic, Enantioselective Reduction of β‑Keto Esters

A pH-independent asymmetric transfer hydrogenation of β-keto esters in water with formic acid/sodium formate is described. The reaction is conducted open to air and gives access to β-hydroxy esters in excellent yields and selectivities

Transfer Hydrogenation in Water: Enantioselective, Catalytic Reduction of (<i>E</i>)-β,β-Disubstituted Nitroalkenes

A mild catalytic asymmetric transfer hydrogenation of β,β-disubstituted nitroalkenes is reported. Formic acid is used as a reductant in combination with an Ir catalyst. The reaction is conducted in water at low pH and open to air to give adducts in preparatively useful yield and selectivity

Transfer Hydrogenation in Water: Enantioselective, Catalytic Reduction of α-Cyano and α-Nitro Substituted Acetophenones

Catalytic reduction of α-substituted acetophenones under conditions involving asymmetric transfer hydrogenation in water is described. The reaction is conducted in water and open to air, and formic acid is used as reductant