Reactivity of vinyl and alkynyl zirconium complexes with the di- ansa-[1,1′,2,2′-bis(dimethylsilanediyl) dicyclopentadienyl] ligand

Abstract

Vinylation of the chloro–ethyl and dichloro zirconium complexes [Zr(CpSi 2Cp)ClX] (CpSi 2Cp=1,1′,2,2′-(SiMe 2) 2(η 5-C 5H 3) 2; X=Et, Cl) with one or two equivalents of Mg(CHCH 2)Cl gave the new zirconacyclopentane [Zr(CpSi 2Cp){η 2-CH 2(CH 2) 2CH 2}] and (η 4-butadiene)zirconium [Zr(CpSi 2Cp){η 4-(butadiene)}] complexes, respectively. Addition of a toluene solution of PhCCPh to the zirconacyclopentane compound afforded the zirconacyclopentadiene derivative [Zr(CpSi 2Cp){η 2-(CPhCPhCPhCPh)}]. Reaction of the chloro–ethyl zirconium complex with LiCCPh afforded the alkynyl compound [Zr(CpSi 2Cp)Et(CCPh)] which reacted with CN(2,6-Me 2C 6H 3) to give the insertion product [Zr(CpSi 2Cp)(CCPh){η 2-C(Et)N(2,6-Me 2C 6H 3)}]. Reactions of the chloro–ethyl [Zr(CpSi 2Cp)EtCl] and alkynyl-ethyl [Zr(CpSi 2Cp)Et(CCPh)] complexes with the Lewis acid B(C 6F 5) 3 yielding various cationic species have been monitored by 1H-NMR spectroscopy. The new complexes reported and their intermediates have been identified by IR and 1H- and 13C-NMR spectroscopy.