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Please login to access the full content or check if you have access via Method 8: Bis(η5-cyclopentadienyl)zirconium(II)-Catalyzed C—C Bond Formation

DOI: 10.1055/sos-SD-002-00797

Negishi, E.-i.; Takahashi, T.Science of Synthesis, (20032794.

The first catalytic cycle of a CC bond formation reaction involving a zirconium(II)alkene complex was reported in 1990.[‌262‌,‌263‌] This catalytic cycle was found from a study on the stoichiometric reaction of ethylmagnesium bromide with a zirconacyclopentane, which was prepared by the reaction of bis(η5-cyclopentadienyl)(η2-ethene)zirconium(II) (384) with alk-1-enes. The catalytic cycle involves (1) coupling of bis(η5-cyclopentadi­enyl)(η2-ethene)zirconium(II) (384) and an alkene to give zirconacyclopentane 411, (2) transmetalation of the zirconacyclopentane by reaction with ethylmagnesium bromide,[‌262‌,‌263‌] and (3) β-hydrogen abstraction from the ethyl group of 412 to give 413 with concomitant regeneration of the zirconium(II)ethene complex 384[‌12‌] (Scheme 149).

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