Chlorosilanes: hydrolytic condensation

The hydrolytic condensation of tert-butyltrichlorosilane ISu SiC l, in water was performed in a 25-fold up-scaling of the HTE synthesis. Bu SiCh is a solid at room temperature since the HTE workstation employed can only handle liquids, the tri-chlorosilane was dissolved in a minimum of acetonitrile. The same procedure was used for the up-scaled synthesis. After 18 h of reaction at 50 °C, the reaction mixture contained a white precipitate, which was isolated by filtration (fraction A). 

After our report of all-cis cyclic silanols, Shchegolikhina s group reported the synthesis of cyclic silanols via sodium or potassium cyclic silanolates from substituted trialkoxysilanes (1). Overall yields are better than those by hydrolytic condensation of tri-chlorosilanes. Kawakami s group applied this method and reported the synthesis of phenyl and isobutyl cyclic silanols (2). We slightly modified Kawakami s method and obtained all-cis-[/-PrSi 0H)0]4 in 74% yield. 

In addition to the unconventional methods of the formation of siloxane bonds such as those discussed earlier, the non-hydrolytic reactions of chlorosilanes in the presence of dimethyl sulfoxide, 7 and the reaction of dichlorosilanes with metal oxides,111 a new method has recently been discovered which involves the condensation of alkoxysilanes with organohydrosilanes with the release of hydrocarbon.112... 

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