Process for the preparation of substituted fluorenes

摘要

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.