Organometallic compounds alkyl group exchange

Methyl, butyl, or trimethylsilylmethyl compounds of Na, K, Rb, or Cs can be used to generate other organometallic compounds by alkyl group exchange. 

Organo-Zn, -Cd and -Hg derivatives can be prepared from other compounds by proton-metal exchange with acidic hydrocarbons by olefin insertion and by metal-metal exchange with other organometallics. In all cases alkyl groups are substituted by other... 

Information for other organometallic compounds is scarce. The corresponding methyl and ethyl derivatives of mercury, tin, and silicon were shown to undergo redistribution to yield random equilibrium mixtures of all possible metal alkyls. Rapid intermolecular exchange of the methyl groups in mixtures of trimethylaluminum-dimethylcadmium and dimethylzinc-dimethylcadmium was also demonstrated by NMR. The redistribution of mercury derivatives was found to be much slower. Further data are also available for thallium. - The four-center intermediate 154 was suggested to explain the observations [Eq. (6.149)] ... 

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