Abstract: The invention relaters to a process for the production of an (S)- or (R)-4-halo-3-hydroxybutyrate, comprising reacting a 4-haloacetoacetate with hydrogen in the presence of a solvent, the solvent being a solvent mixture, which comprises a first solvent and a second solvent, wherein the first solvent is an aliphatic alcohol, preferably methanol, ethanol or propanol, and the second solvent is aprotic and comprises at least one oxygen atom; and a catalyst of the formula [RuXYZ]X, wherein X is halogen, preferably Cl or Br, or OAc, acetoacetate, allyl or ClO4, Y is a bidentate organic ligand having two phosphine groups, and Z is an arene, preferably cymene, benzene, xylene or toluene, or a polyene, preferably a diene, or an alkene.

Abstract: The invention relaters to a process for the production of an (S)- or (R)-4-halo-3-hydroxybutyrate, comprising reacting a 4-haloacetoacetate with hydrogen in the presence of a solvent, the solvent being a solvent mixture, which comprises a first solvent and a second solvent, wherein the first solvent is an aliphatic alcohol, preferably methanol, ethanol or propanol, and the second solvent is aprotic and comprises at least one oxygen atom; and a catalyst of the formula [RuXYZ]X, wherein X is halogen, preferably Cl or Br, or OAc, acetoacetate, allyl or ClO4, Y is a bidentate organic ligand having two phosphine groups, and Z is an arene, preferably cymene, benzene, xylene or toluene, or a polyene, preferably a diene, or an alkene.

Abstract: The present invention relates to a process for the efficient preparation of enantiomerically enriched beta amino acid derivatives wherein the amino group is unprotected. The product chiral beta amino acid derivatives are useful in the asymmetric synthesis of biologically active molecules. The process comprises an enantioselective hydrogenation of an amine-unprotected prochiral beta-amino acrylic acid or derivative thereof in the presence of a rhodium metal precursor complexed with a chiral mono- or bisphosphine ligand.

Abstract: Compounds of the formula (I) wherein R is phenyl, or phenyl substituted by Cl, Br, C1-C4alkyl or CF3; R1 is H or methyl or ethyl; R2 is H or methyl or acyl; R3 is H or methyl; R?4 is —CH3 or ?CH2; may be obtained in high enantiopurity by hydrogenation of a compound of the formula (II) wherein R and R3 are as in formula (I); A is acyl; and R4 is —CH3 or ?CH2; in the presence of a chiral Rhodium or Ruthenium catalyst. Residues R1 as methyl or ethyl and/or R2 as H or methyl may subsequently be introduced without racemization by deacylation and optional alkylation.

Abstract: The present invention relates to a process for the efficient preparation of enantiomerically enriched beta amino acid derivatives wherein the amino group is unprotected. The product chiral beta amino acid derivatives are useful in the asymmetric synthesis of biologically active molecules. The process comprises an enantioselective hydrogenation of an amine-unprotected prochiral beta-amino acrylic acid or derivative thereof in the presence of a rhodium metal precursor complexed with a chiral mono- or bisphosphine ligand.

Abstract: The present invention is based around the discoveries that novel ligands of formula (4) and the opposite enantiomers thereof, (i) have utility as components of catalysts for asymmetric hydrogenation and (ii) are readily accessible by an efficient general synthetic route. In particular, ruthenium-diamine complexes of the ligands (4) are highly active and selective catalysts for the asymmetric hydrogenation of ketones.