Metallocenes having bicyclic cyclopentadiene derivatives as ligands, processes for their preparation and their use as catalysts

US5268495A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Herbert Riepl · Dachau, DE
• Wolfgang Anton Herrmann · Freising, DE
• Jurgen Rohrmann · Kelkheim, DE

Key dates

• Filing date: Dec 9, 1991
• Grant date: Dec 7, 1993
• Expiry date: Dec 9, 2011

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S526/943
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention relates to a process for the preparation of a compound of the formula XI ##STR1## wherein preferably M.sup.1 is zirconium, the radicals R.sup.1 are alkyl, the radicals R.sup.2 are halogen or alkyl, R.sup.3 is dimethylsilyl or ethylene and n is 2-18, wherein a compound of the formula II ##STR2## is reacted with an alkali metal or alkaline earth metal salt of a malonic ester and then with an alkyl halide, the reaction product is converted by decarboxylation into the corresponding lactone, which is further reacted by known methods to give the compound XI. The compounds of the formula XI, some of which are novel, can advantageously be used as catalysts for olefin polymerization.