Patent ID: 7544819

Claim:
Process for preparing stereoisomerically enriched compounds of the formula (I), wherein “*” is a carbon atom having an (R) or (S) configuration and R 1 , R 2 , R 3 and R 4 are each, independently of one another, hydrogen, alkyl, aryl, arylalkyl, haloalkyl or a radical of one of formulae (IIa) to (IIf) A-B-D-E (IIa) A-E (IIb) A-SO 2 -E (IIc) A-B—SO 2 R 6 (IId) A-SO 3 W (IIe) A-COW (IIf) wherein, in the formulae (IIa) to (IIf) A is absent or is an alkylene or haloalkylene radical and B is absent or is oxygen or NR 5 , where R 5 is nitrogen, arylalkyl or aryl, and D is a carbonyl group and E is R 6 , OR 6 , NHR 7 or N(R 7 ) 2 , where R 6 is alkyl, arylalkyl or aryl and the radicals R 7 each, independently of one another, alkyl, arylalkyl or aryl or the moiety N(R 7 ) 2 is a cyclic amino radical having from 4 to 12 carbon atoms and W is OH, NH 2 , or OM, where M is an alkali metal ion, half an equivalent of an alkaline earth metal ion, an ammonium ion or an organic ammonium ion, or two of the radicals R 1 , R 2 , R 3 and R 4 are together part of a 3- to 7-membered ring having a total of from 3 to 16 carbon atoms, comprising reacting compounds of the formula (III), where R 1 , R 2 , R 3 and R 4 are each, independently of one another, as defined above, with compounds of the formula (IV), R 8 —OOH (IV) where R 8 is hydrogen, alkyl or arylalkyl, in the presence of a ruthenium complex which bears as ligands both compounds of the formula (V) where R 9 is hydrogen, halogen, hydroxy, alkoxy, hydroxycarbonyl, alkoxycarbonyl, alkyl, arylalkyl or aryl and L 1 and L 2 are each, independently of one another, a radical of the formula (VI-a) or a radical of the formula (VI-b) where “*1” and/or “*2” and/or “*3” are each an asymmetric carbon atom in the (R) or (S) configuration, the arrow points to the point of bonding to the central pyridine ring and R 10a , R 10b and R 11 are each, independently of one another, alkyl, alkoxyalkyl, trialkylsiloxyalkyl, alkoxycarbonyl, arylalkyl or aryl or R 10a and R 11 or R 10a and R 10b are part of a cyclic radical having a total of from 5 to 16 carbon atoms and R 11 and/or R 10a and/or R 10b may also be hydrogen, and compounds of the formula (VII) where X 1 , X 2 and X 3 are each, independently of one another, N, CH or CR 12 and R 12 is hydrogen, halogen, hydroxy, hydroxycarbonyl, alkoxycarbonyl, alkoxy, alkoxyalkyl, arylalkyl or aryl and n is 0, 1, 2 or 3, preferably 0 or 1 and particularly preferably 0, and wherein the reaction is carried out in the presence of secondary or tertiary alcohols as solvents.