Preparation of a Bridged Verbenindenyl Ligand for Metallocenes

Abstract

The preparation of an annulated verbenyl indene is described. Reduction of the verbenone oxo group and water elimination provided a verbenylindene with an embedded fulvene unit, which was reduced to an annulated verbenylindene, a fluorene derivative. The ansa‐bridge was constructed between the fluorene 9‐position and 6,6‐dimethylfulvene by way of the lithiated indene. Dilithiation of the ligand and treatment with ZrCl₄ yielded the corresponding zirconocene.

Keywords:

• annulated indene
• ansa ligand
• fulvenes
• verbenylindene

Acknowledgment

We thank Dirk Petersen at the Department Chemistry, University of Oslo, for the NOESY experiments, which led to the assignment of structure 8 for the zirconation product.