Patent ID: 8071802

Claim:
Process for preparing bridged, stereorigid, diastereomerically pure dialkoxide metallocenes and diaryl oxide metallocenes of the general formula Q(Cp)(Cpâ€²)M(OR 3 ) 2 , in which Cp=a cyclopentadienyl, an indenyl or a fluorenyl radical, Cpâ€²=one of the Cp groups, Q=a single- or multimembered bridge (R 1 â€”Zâ€”R 2 )b between Cp and Cpâ€², in which R 1 and R 2 may be the same or different and are each a hydrogen atom, a C 1 -C 10 -alkyl group or a C 6 -C 10 -aryl group, and Z is carbon, silicon or germanium where b=1, 2 or 3, M=a transition metal of group 4, O=oxygen R 3 =a C 1 -C 10 -alkyl group or a C 6 -C 10 -aryl group, where the alkyl group may be branched or unbranched and may be substituted by aryl groups, and the aryl group may contain further substituents, characterized in that, in the first stage, a bridged, stereorigid metallocene dihalide in the form of a diastereomeric rac/meso mixture, said metallocene dihalide having the general formula Q(Cp)(CpOM(X) 2 , in which Cp=a cyclopentadienyl, an indenyl or a fluorenyl radical, Cpâ€²=one of the Cp groups, which may be different or the same, Q=a single- or multimembered bridge (R 1 â€”Zâ€”R 2 )b between Cp and Cpâ€², in which R 1 and R 2 may be the same or different and are each a hydrogen atom, a C 1 -C 10 -alkyl group or a C 6 C 10 -aryl group, and Z is carbon, silicon or germanium where b=1, 2 or 3, M=a transition metal of group 4, X=a halogen, is reacted with an alkylating reagent of the general formula R 4 -Mâ€²-(X)n, in which R 4 =a C 1 -C 10 -alkyl group or a C 6 -C 10 -aryl group, Mâ€²=Mg, Na or Li X=halogen, n=the oxidation number of M reduced by 1, and then the resulting reaction mixture or the intermediately isolated dialkylmetallocene is reacted with an alcohol or an aryl alcohol of the general formula .HOâ€”R 3 , in which HO=a hydroxyl group, R 3 =a C 1 -C 10 -alkyl group or a C 6 -C 10 -aryl group, where the alkyl group may be branched or unbranched and may be substituted by aryl groups, and the aryl group may contain further substituents.