摘要 |
Process for preparing bridged, stereorigid, stereomerically pure dialkoxide metallocenes, diaryl oxide metallocenes and diphenoxide metallocenes of formula Q(Cp)(Cp′)M(OR3)2 in which Cp and Cp′ are independently cyclopentadienyl, indenyl or fluorenyl; Q is a bridge between Cp and Cp′; M is a group 4 transition metal, especially Zr, Hf or Ti; R3 is C1-C10 alkyl, optionally substituted by aryl groups, or optionally substituted C6-C10 aryl, characterized in that, a bridged, stereorigid metallocene dihalide Q(Cp)(Cp′)M(X)2, in the form of a rac/meso mixture, is reacted with an alkylating reagent R4-M-(X)n wherein R4 is C1-C10 alkyl or C6-C10 aryl; M is an alkali metal or alkaline earth metal; X is halogen; n is the oxidation number of M reduced by 1; and the resulting reaction mixture or isolated dialkylmetallocene is reacted with an alcohol, an aryl alcohol or a phenol of the general formula HO—R3. |