Methods for the preparation of fluorenyl-type ligand structures and
substituted fluorenyl groups which may be employed in metallocene-type
olefin polymerization catalysts. There is provided a
2,2'-dihalogen-diphenylmethylene having a methylene bridge connecting a
pair of phenyl groups. Each phenyl group has a halogen on a proximal
carbon atom relative to the methylene bridge. The halogenated
diphenylmethylene is reacted with a coupling agent comprising a Group 2
or 12 transition metal in the presence of a nickel or palladium-based
catalyst to remove the halogen atoms from the phenyl groups and couple
the phenyl groups at the proximal carbon atoms to produce a fluorene
ligand structure. The coupling agent may be zinc, cadmium or magnesium
and the catalyst may be a monophosphene nickel complex. The halogenated
diphenylmethylene may be an unsubstituted ligand structure or a
monosubstituted or disubstituted ligand structure. The halogenated
diphenylmethylene may be monosubstituted with a tertiary butyl group or
may be a dialkyl diphenylmethylene having alkyl substituents at the
directly distal positions of the phenyl groups relative to the methylene
bridge.