Substituent Exchange Reactions Catalyzed by Peroxides

The hydrogen atom of an alkyl group or of a Si—H bond can be captured by organic radicals such as benzoyl peroxide, etc. The disilanyl radicals formed in this way are readily halogenated. 

Some reactions are known for preparation of halogenated disilanes by the following mechanism  

Di-t-butylperoxide or benzoylperoxide reacts with Si2me6 in CC14 primarily producing Si2mesCH2 radicals which further react with chlorine atoms from the solvent492. In an inert solvent, the radicals are able to react with for example CH2=CH. Si2mes, or, in the absence of another reagent, between themselves to form dimers  

The dimeric compound was also prepared by an independent synthesis492). Similar investigations had been carried out before with ethyl derivatives686). Kinetic measurements are available for the radical H-splitting by t-butylper-oxide486). 

Perbenzoic acid reacts with organic disilanes by oxidation to the corresponding disiloxanes488) in a second-order reaction. A substitution on the phenyl group of the phenylpentamethyl-disilanes increases the nucleophilic reaction rate of the Si-Si oxidation and increases pw— d conjugation from the phenyl-group to the silicon. 

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