Exchange Reactions of Galliozirconocene Complexes

The complex Cp2Zr(p-r 1 n2-C6HR)(jj-CH3)GaMe2 112 reacts readily with norbornene at room temperature to give trimethylgallium and the metallacyclic product 121. The norbor-nene/(r 2-cyclohexyne)ZrCp2 addition product was tentatively identified on the basis of its spectroscopic data [194], 

Complex 115 reacts analogously with ethene. At ambient temperatures, trimethylgallium is rapidly liberated. At the same time, the remaining (r 2-aryne)zirconocene fragment takes up 1 equivalent of ethene to form the metallaindane system 122. Compound 122 was identified by comparison with an authentic sample [194], Prolonged exposure of the reaction mixture to ethene eventually led to the formation of 123. 

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