New polyunsaturated silahydrocarbons

12-Membered highly unsaturated macrocyclic silahydrocarbon containing exocyclic methyl and benzyl groups is synthesized by the reaction of benzylmethyldi(bromomagnesiumethynyl)silane with dimethyldichlorosilane. Hydrosilylation of benzyl(triethynyl)silane with trichlorosilane with subsequent reaction of the formed adduct with trimethylsilylmagnesium bromide leads to the spherical dendrimer (N_C = 3) containing the benzyl group at the central Si atom, -CH=CH- groups in the inner sphere and numerous triple bonds on periphery. NMR spectra of the obtained compounds were studied.     

Novel Highly Unsaturated Macrocyclic and Macrobicyclic Silahydrocarbons Containing Si-H Bonds and Exocyclic Vinyl Groups

The first representative of cycloorganylhydrosilalkynes (C≡CSiHR)_n, tetramethylcyclotetrasilethyne, was prepared by organomagnesium synthesis. The same procedure was used to synthesize 15-membered polyunsaturated silahydrocarbons containing both triple and double bonds in the ring and an exocyclic vinyl group. Organomagnesium synthesis was also used for preparing previously unknown polyunsaturated macrobicyclic silahydrocarbons containing a -CH₂CH₂- bridge. The ¹H, ¹³C, and ²⁹Si NMR and IR spectra of the synthesized compounds were studied.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 7, 2005, pp. 1157–1160.Original Russian Text Copyright © 2005 by O. Yarosh, Zhilitskaya, Istomina, N. Yarosh, Albanov, Voronkov.     

Cotrimerization of mono- and dinitriles of perfluorocarboxylic acids under high pressures

Cotrimerization of mono- and dinitriles of perfluorocarboxylic acids under high pressures affords oligoperfluoroalkylenetriazines. These oligomers are highly efficient stabilizers of thermooxidative destruction of perfluoropolyethers, when they are contacting with metals at elevated temperatures.Deceased.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1814–1816, September, 1995.     

1,3-Bis[2-(ethynyldimethylsilyl)vinyl]tetramethyldisiloxane and Macrocyclic Polyunsaturated Siloxanes on Its Basis

Hydrosilylation of diethynyldimethylsilane with tetramethyldisiloxane in the presence of chloroplatinic acid give rise to a mixture of three stereoisomers of 1,3-bis[2-(ethynyldimethylsilyl)vinyl]tetramethyldisiloxane: trans-trans, gem-trans, and gem-gem. Hydrolysis of chloro[2-(ethynyldimethylsilyl)vinyl]dimethylsilane provides the trans-trans isomer of 1,3-bis[2-(ethynyldimethylsilyl)vinyl]tetramethyldisiloxane exclusively. Reactions of an organomagnesium derivative of the disiloxane with dichlorodiorganylsilanes allowed synthesis of novel polyunsaturated macrocyclic siloxanes. The ¹H, ¹³C, and ²⁹Si NMR spectra of the products were studied.     

Bromination and iodination of trialkylethynylsilanes

Conclusions The addition of bromine and iodine to trimethyl- and dimethylethylethynylsilanes has been studied. The halogenation of these compounds takes place stepwise. The first molecule of bromine adds at 30–50° and the second at 70–90°. In the case of bromination under UV irradiation, hydrogen bromide is eliminated as a side-reaction. The addition of iodine ceases at the stage of the formation of the diiodovinylsilanes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 693–694, March, 1967.