Ferrocene diphosphines as ligands for homogeneous catalysts

A compound of formula I ##STR7## wherein R.sub.1 is C.sub.1 -C.sub.8 alkyl, phenyl or phenyl which is substituted by 1 to 3 C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy groups;

• R.sub.2 and R.sub.3 are each independently of the other C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.12 cycloalkyl, phenyl, C.sub.1 -C.sub.4 alkyl- or C.sub.1 -C.sub.4 alkyl- or C.sub.1 -C.sub.4 alkoxy-substituted C.sub.5 -C.sub.12 cycloalkyl, or phenyl which is substituted by one to three identical or different members selected from the group consisting of C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, --SiR.sub.4 R.sub.4 R.sub.6, halogen, --SO.sub.3 M, --CO.sub.2 M, --PO.sub.3 M, --NR.sub.7 R.sub.8 and --[.sup..sym. NR.sub.7 R.sub.8 R.sub.9 ]X.sup..crclbar. ;
• or the group --PR.sub.2 R.sub.3 is a radical of formula II ##STR8## and R.sub.4, R.sub.5 and R.sub.6 are each independently of one another C.sub.1 -C.sub.12 alkyl or phenyl, R.sub.7 and R.sub.8 are H, C.sub.1 -C.sub.12 alkyl, phenyl or R.sub.7 and R.sub.8, taken together, are tetramethylene, pentamethylene or 3-oxa-1,5-pentylene, R.sub.9 is H or C.sub.1 -C.sub.4 alkyl, R.sub.10 and R.sub.11 are identical and are C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.12 cycloalkyl, C.sub.1 -C.sub.4 alkyl-or C.sub.1 -C.sub.4 alkoxy-substituted C.sub.5 -C.sub.12 cycloalkyl or phenyl which is substituted by 1 to 3 identical or different members selected from the group consisting of C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, --SiR.sub.4 R.sub.4 R.sub.6, halogen, --SO.sub.3 M, --CO.sub.2 M, --PO.sub.3 M, --NR.sub.7 R.sub.8 or --[.sup..sym. NR.sub.7 R.sub.8 R.sub.9 ]X.sup..crclbar. ;
• or R.sub.10 and R.sub. 11 are different and are C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.12 cycloalkyl, C.sub.1 -C.sub.4 alkyl- or C.sub.1 -C.sub.4 alkoxy-substituted C.sub.5 -C.sub.12 cycloalkyl, phenyl or phenyl which is substituted by 1 to 3 identical or different members selected from the group consisting of C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, --SiR.sub.4 R.sub.5 R.sub.6, halogen, --SO.sub.3 M, --CO.sub.2 M, --PO.sub.3 M.sub.2, --NR.sub.7 R.sub.8 or --[.sup..sym. NR.sub.7 R.sub.8 R.sub.9 ]X.sup..crclbar. ;
• or the group --PR .sub.10 R.sub.11 is a radical of formula II ##STR9## M is H or an alkali metal, X.sup..crclbar. is the anion of a monobasic acid, and * is a stereogenic carbon atom, in the form of the racemates or diastereoisomers thereof or of a mixture of diastereoisomers.