Hydrosilylation halogenated alkenes

The asymmetric hydrosilylation of alkenes mentioned earlier (Scheme 1) can be used to prepare optically active bromides by halogenation of the alkyl-pentafluorosilicate intermediates (1) with inversion of configuration using N-bromosuccinimide. Treatment of organoboranes with ICl provides a rapid mild route from alkenes to anti-Markovnikov iodides (Scheme 37), although all three alkyl groups of the organoborane do not react with the ICl. " ... 

Trichlorosilanes are readily transformed to the pentafluorosilicate compounds (100) and (101) by reaction with excess potassium fluoride. The C—Si bond of the hexavalent organosilicon species is converted into a C—X (X = halogen or heteroatom like hydroxy and alkoxy) or a C—C bond. Thus, through the hydrosilylation reaction net transformations of alkenes and alkynes to halides, ethers and alcohols, as well as the construction of carbon frameworks, is easily achieved (Scheme 18). ... 

In the presence of HjPtClg, hydrosilanes add to various 1-alkenes to give the corresponding terminal adducts in high yields ". Halogenated olefins such as 3,4-dichlo-robut-l-ene , 3,3,3-trifluoropropene , perfluoroethylene , and 1,1-difluoroethene are also readily hydrosilylated. 1,1-Difluoroethene is hydrosilylated regioselectively to give... 

Anti-Markownikoff hydrobromination of alkenes. This reaction can be carried out by hydrosilylation of an aikene followed by conversion to an organopenta-fluorosilicate, in which the C—Si bonds arc highly reactive to halogens. The method can also be used for preparation of alkenyl halides (last example). ... 

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