C–H bond activation of ethylene by a zirconacycle.

The reaction of C2H4 and β-SiH containing azasilazirconacycle Cp2Zr{κ2-N(SiHMe2)SiHMeCH2} (3), formed via a γ-abstraction reaction of Cp2Zr{N(SiHMe2)2}H (1), follows an unusual pathway in which a rare σ-bond metathesis reaction of ethylene generates a vinyl intermediate. That species undergoes a β-hydrogen abstraction under the reaction conditions to form a zirconium silanimine ethylene adduct en route to the metallacyclopentane product. [ABSTRACT FROM AUTHOR]