Xylyl silicone

Asymmetric intramolecular hydrosilylation.9 The intramolecular hydrosilyl-ation of allylic alcohols (14, 137) can be enantioselective when catalyzed by Rh(I) complexed with either (R)-BINAP or (R.R)-DIOP. The enantioselectivity is dependent on the groups attached to silicon, being higher with a phenyl than with a methyl group. Highest enantioselectivity (93% ee) was obtained with the di(3,5-xylyl)silyl ether, ROSiH[C6H3(CH3)2-3,5]2. 

Polymer Preparation. In order to prepare silicon containing polymers which include the m-xylyl and dimethylenebiphenyl moieties, two distinct polymerization routes were chosen. The first route consists of condensation of a dichlorodialkyl(or aryl)silane with a dicarbanion, namely 12 or 12. The material which is formed consists of an all silicon-carbon and carbon-carbon backbone. The second polymerization utilizes the bis(silanol) monomers discussed in the previous section. These materials are heated and undergo a self condensation reaction to form polymers which contain silicon-carbon, silicon-oxygen, and carbon-carbon bonds in the backbone. 

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