Asymmetric Hydrogenation of α‐Keto Phosphonates with Chiral Palladium Catalysts

Abstract

Abstract Under atmospheric hydrogen pressure, a catalytic amount of palladium(II) trifluoroacetate and ( R )‐MeO‐BIPHEP in 2,2,2‐trifluoroethanol promoted the asymmetric hydrogenation of diisopropyl α‐keto phosphonates 1 to afford the corresponding α‐hydroxy phosphonates 2 in excellent yields and with a moderate enantioselectivities of up to 55 % ee . Racemic α‐aryl‐α‐hydroxy phosphonates can be prepared by using palladium on carbon as the catalyst. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)