Ferrocenyl diphosphines as ligands for homogeneous catalysts

摘要

Compounds of formula I (I) wherein R1 is C1-C8alkyl, phenyl or phenyl which is substituted by 1 to 3 C1-C4alkyl or C1-C4alkoxy groups; R2 and R3 are identical and are C1-C12alkyl, C5-C12cycloalkyl or C1-C4alkyl- or C1-C4alkoxy-substituted C5-C12cycloalkyl, or phenyl which is substituted by one to three identical or different members selected from the group consisting of C1-C4alkyl, C1-C4alkoxy, -SiR4R5R6, halogen, -SO3M, -CO2M, -PO3M,-NR7R8 and -[(+)NR7R8R9]X(-); or R2 and R3 are different and are C1-C12alkyl, C5-C12cycloalkyl, C1-C4alkyl- or C1-C4alkoxy-substituted C5-C12cycloalkyl, phenyl or phenyl which is substituted by one to three identical or different members selected from the group consisting of C1-C4alkyl, C1-C4alkoxy, -SiR4R5R6, halogen, -SO3M, -CO2M, -PO3M2, -NR7R8 and -[(+)NR7R8R9]X(-); or the group -PR2R3 is a radical of formula II (II) and R4, R5 and R6 are each independently of one another C1-C12alkyl or phenyl, R7 and R8 are H, C1-C2alkyl, phenyl or R7 and R8, taken together, are tetramethylene, pentamethylene or 3-oxa-1,5-pentylene, R9 is H or C1-C4alkyl, M is H or an alkali metal, X(-) is the anion of a monobasic acid, and * is a stereogenic carbon atom, in the form of their racemates and diastereoisomers or mixtures of diastereoisomers. Rhodium and iridium complexes with these ligands are suitable for use as homogeneous enantioselective catalysts for the hydrogenation of prochiral compounds containing carbon double bonds or carbon/hetero atom double bonds.