Patent ID: 7473792

Claim:
A process for transition metal-catalyzed asymmetric hydrogenation of acrylic acid derivatives of the formula (I) in which R1 is H or an optionally substituted C 1 -C 20 -alkyl, C 5 -C 20 -aryl or C 5 -C 20 -heteroaryl radical, R2 is an optionally substituted C 1 -C 20 -alkyl, C 5 -C 20 -aryl or C 5 -C 20 -heteroaryl radical, and R3 is H or a C 1 -C 6 -alkyl radical, which comprises hydrogenating compounds of the formula (I), optionally in a solvent, in the presence of one or more hydrogen donors, using a catalyst system which comprises a transition metal from the group of ruthenium, rhodium and iridium and a combination of a chiral phosphorus ligand of the formula (II) in which Cn, together with the two oxygen atoms and the phosphorus atom, forms an optionally substituted ring having from 2 to 6 carbon atoms and R4 is an optionally substituted alkyl, aryl, alkoxy or aryloxy radical or NR5R6 where R5 and R6 may each independently be H or an optionally substituted alkyl, aryl, aralkyl or alkaryl radical, or, together with the nitrogen atom, may form a ring, and an achiral phosphine ligand of the formula (III) P(R) 3 in which R is an optionally substituted alkyl or aryl radical, to the corresponding compounds of the formula (IV) in which R1, R2 and R3 are each as defined above.