Reaction of alkylzirconocene cation complexes with (R-C=C-)2SiR2 reagents: Preparation of heterodimetallic compounds containing a μ-alkyayl ligand bridge between zirconium and silicon

Article abstract of DOI:10.1002/cber.19961290103

The methylzirconocene cation, employed as the [Cp₂ZrCH₃(THF)]⁺BPh₄^- reagent la reacts with (R′C=C)₂SiR₂ substrates (6a-d) by means of carbometallation of an alkynyi group to yield the mixed metal ring systems 8a-d, containing both a 1,1-disubstituted ,u-alkenyl and an alkynyi bridge between zirconium and silicon (e.g. shown by X-ray crystal structure analyses of complexes 8a and 8c). A similar addition reaction takes place upon treatment of the (butadiene)zirconocene/tris(pentafluorophenyl)borane 1:1 addition product 9 with (CH₃-C=C)₂Si(CH₃)₂ (6c) to give 10. Here the incipient alky] zirconocene cation character of the metallocene/borate betaine complex 9 shows up in the alkynyl silane carbometallation reaction.