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Please login to access the full content or check if you have access via Variation 4: Formation of Bis(η5-cyclopentadienyl)zirconium–Alkene Complexes

DOI: 10.1055/sos-SD-002-00797

Negishi, E.-i.; Takahashi, T.Science of Synthesis, (20032789.

One of the most useful zirconiumalkene complexes is (η2-but-1-ene)bis(η5-cyclopentadi­enyl)zirconium(II) (382), which is prepared in situ from dibutylbis(η5-cyclopentadienyl)zirconium(IV) (64), commonly referred to as the Negishi reagent. Since the butene ligand is very labile, this complex acts as a Zr(Cp)2 equivalent.[‌209‌] The conversion of dibutyl­bis(η5-cyclopentadienyl)zirconium(IV) (64) into 382 might be rather complicated;[‌332‌,‌333‌] formally, however, β-hydrogen abstraction is the key step for the formation of the butene complex. In the presence of trimethylphosphine, the formation of (η2-but-1-ene)bis(η5-cyclopentadienyl)(trimethylphosphine)zirconium(II) (383) is observed (Scheme 140).[‌208‌,‌334‌]

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