Hydrosilylation functional material synthesis

The hydrosilylation processes of carbon-carbon multiple bonds, applied in the field of polymer chemistry and materials science, are described in part three (section 4) of this article. It includes functionalization (and cross-linking) of polysiloxanes and (poly)silsesquioxanes as well as hydrosilylation polymerization of difunctional organosilicon monomers besides the application of hydrosilylation in the synthesis of silicon-containing dendrimers and hybrid organic-inorganic materials. 

Just as the hydrosilylation reaction is important in the synthesis of silanes, so it also serves as a useful route to functional polysiloxanes. The same variety of chemistry as previously described for silanes is available and two further examples are given in equations 82 and 83. One of the main advantages of this route is that the silicon hydride prepolymers are well characterized and readily available materials, which in turn leads to well-defined organofunctional products. A disadvantage is the low efficiency in the use of the precious metal catalyst and the difficulty of its recovery. This is particularly true for systems containing a low level of functionality but this can be partially overcome by using recyclable platinum catalysts on solid supports216,217. 

Modifications of organic polymers with organosilicon compounds were reviewed by McGrath and co-workers (32). Synthesis and properties of silicon-containing dendrimers including hydrosilylation were the subjects of the review by Majoral and Caminade (33). Functionalization of silsesquioxanes via hydrosilylation (34,35) and production of new composite materials (36) were also presented. 

Allyl derivatives of hydrocarbons with functional group were often used as starting materials. The hydrosilylation of allylperfluoroethers with methyl(chloro)silanes is a frequently used method for synthesis (after hydrolysis and polycondensation) of fluorine-containing polymers (162). Unsaturated esters of unsaturated carboxylic acids in the reaction of hydrosilylation give silyl derivatives of carboxylic acid (e.g., 3-methacryloxypropyltriethoxysilane). 

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