Halogen-Containing Bonds

Besides the ones discussed in the previous sections, the only other silylene insertion reaction involving silicon-containing bonds is the reaction of SiClj with halo-substituted polysilanes as shown in equation (93).  

The apparent insertions of SiF2 into the C-F bonds of fluoroethylenes and fluorobenzenes as indicated in both Tables 5 and 6 were believed not to be direct insertion processes. Interactions of SiF2 with the double bonds may be the primary processes followed by rearrangements to give the products finally observed. 

It is also believed that SiF2 may insert into HF to give SiHF, and SiCl2 may insert into HCl to give SiHCl3.  

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Because only one stable electroactive product arises from the reduction of /7-chlorobenzonitrile, the interpretation of the cyclic voltammetric behavior is relatively straightforward. The fact that electron attachment to halogen-containing compounds frequently results in the cleavage of the carbon-halogen bond immediately suggests benzonitrile as a possible product. The similarity between the cyclic voltammetric behavior of benzonitrile and that of the p-chlorobenzo-nitrile reduction product supports this prediction (see Fig. 21.1). 

Interactions of C02 with alkyl halogenides or with compounds containing halogen-nitrogen bonds take place as dissociative electron captures. As a result, free radicals are formed according to Scheme 1-88 ... 

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