Asymmetric Synthesis of Diverse Glycolic Acid Scaffolds via Dynamic Kinetic Resolution of α‑Keto Esters

The dynamic kinetic resolution of α-keto esters
via asymmetric
transfer hydrogenation has been developed as a technique for the highly
stereoselective construction of structurally diverse β-substituted-α-hydroxy
carboxylic acid derivatives. Through the development of a privileged m-terphenylsulfonamide for (arene)­RuCl­(monosulfonamide)
complexes with a high affinity for selective α-keto ester reduction,
excellent levels of chemo-, diastereo-, and enantiocontrol can be
realized in the reduction of β-aryl- and β-chloro-α-keto
esters.