Direct anti-selective asymmetric hydrogenation of α-amino-β-keto esters through dynamic kinetic resolution using Ru-axially chiral phosphine catalysts—stereoselective synthesis of anti-β-hydroxy-α-amino acids
摘要:
The asymmetric hydrogenation of alpha-amino-beta-keto esters using ruthenium (Ru) anti-selectively proceeds via a dynamic kinetic resolution to afford anti-beta-hydroxy-alpha-amino acids with high enantiomeric purities, which are important chiral building blocks for the synthesis of medicines and natural products. A mechanistic investigation has revealed that the Ru-catalyzed asymmetric hydrogenation takes place via the hydrogenation of the double bond in the enol tautomer of the substrate. (C) 2009 Elsevier Ltd. All rights reserved.
The stereoselectivesynthesis of anti β-hydroxy α-amino esters by iridium–SYNPHOS-catalyzed asymmetric hydrogenation of α-amino β-keto ester hydrochlorides is reported. The reaction proceeded through dynamic kinetic resolution to afford a variety of β-hydroxy α-amino ester derivatives with good yields and high level of diastereo- and enantioselectivities (de up to 99%, ee up to 92%).