- (Iodomethyl)fluorosilanes: Synthesis and Reactions
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The methods of synthesis of bifunctional (iodomethyl)fluorosilanes of general formula ICH2SiMenF3–n (n = 0, 2) have been elaborated; the structure was proved by 1H, 13C, 29Si NMR spectroscopy. The reaction of (iodomethyl)dimethylfluorosilane with O-trimethylsilyl derivative of N,N'-dimethylhydrazide of trifluoroacetic acid gives rise to the formation of 2,2,4,4-tetramethyl-6-(trifluoromethyl)-3,4-dihydro-2Н-1,4,5,2-oxadiasilin-4-ium iodide with tetracoordinate silicone atom.
- Gostevskii,Lazareva
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- Synthesis and properties of functionalized alkylalkoxysilanes
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A method of chloroalkylalkoxysilanes synthesis scalable to pilot production has been proposed. Morpholinotrialkoxysilanes have been prepared and studied as vulcanizing agents for low-molecular silicone rubbers. The reaction of N-morpholinomethyltrialkoxysilanes with triethanolamine has afforded N-[(silatranyl)-methyl]morpholine; it has been studied by X-ray analysis.
- Lebedev,Minas’yan,Abramkin,Sheludyakov,Kuzmina,Lebedeva,Surikov,Rybakov
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p. 1859 - 1863
(2016/10/04)
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- New Zwitterionic λ5-Spirosilicates: Syntheses, Single-Crystal X-Ray Structure Analyses, and Solid-State NMR Studies
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The zwitterionic spirocyclic λ5-silicates bissilicate (5; and its monohydrate 5*H2O) and bissilicate (6) were synthesized by various methods including Si-C bond cleavage reactions.The crystal structures of 5, 5*H2O, and 6 were investigated by X-ray diffraction.Furthermore, 5, 5*H2O, 6, and the related zwitterionic λ5-spirosilicates 1*1/4 CH3CN, 2*CH3CN, 3*CH3CN, and 4 were characterized by solid-state NMR spectroscopy (29Si and 15N CP/MAS).The pentacoordinate silicon atoms of 5, 5*H2O (two crystallographically independent zwitterions and two crystallographically independent water molecules), and 6 (two crystallographically independent zwitterions) are surrounded by four oxygen atoms and one carbon atom.The coordination polyhedrons around the silicon atoms of 5 and 6 can be described as distorted (5) or nearly ideal (6) trigonal bipyramids, the carbon atoms being in equatorial positions. 5 forms intramolecular and 6 intermolecular (-> formation of dimeric units) N-H...O hydrogen bonds.The coordination polyhedrons around the two crystallographically independent silicon atoms of 5*H2O can be described as a nearly ideal and slightly distorted square pyramid, respectively, the carbon atoms being in the apical positions.In the crystal lattice of 5*H2O, intermolecular N-H...O and O-H...O hydrogen bonds between the zwitterions and water molecules are observed.The results obtained by X-ray diffraction and solid-state NMR spectroscopy are consistent for each compound studied. Key Words: Spirosilicates, zwitterionic / Silicon, pentacoordinate / Bond cleavage, Si-C / Solid-state NMR, 29Si and 15N
- Tacke, Reinhold,Lopez-Mras, Angel,Sperlich, Joerg,Strohmnann, Carsten,Kuhs, Werner F.,et al.
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p. 851 - 862
(2007/10/02)
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- HETEROGENEOUS REACTIONS VII. FURTHER STUDIES ON THE HETEROGENEOUS GAS/SOLID REACTIONS OF SOLID ALKOXIDE BASES WITH VAPORIZED CHLOROMETHYLDIMETHYLHALOSILANES
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The results of the heterogeneous gas/solid reactions of chloromethyldimethylchloro (and fluoro)silane with solid lithium, sodium and potassium methoxide in the temperature range from 80-160 deg C are presented and discussed.Reaction with lithium methoxide serves as a clean, efficient high yield synthesis of chloromethyldimethylmethoxysilane without the complicating factors of side products or solvent to separate.The reactions of both the sodium and potassium methoxides lead to the displacement of halogen from silicon and to the displacement of the chloromethyl group.New evidence for the mechanism of the latter reaction is presented.With the potassium compound methylethyldimethoxysilane also is formed and a carbene, sila-olefin addition mechanism is suggested.Surprisingly, lithium t-butoxide did not react with the chlorosilane but did react with the fluorosilane to produce chloromethyldimethyl-t-butoxysilane in high purity and excellent yield.The reaction with potassium t-butoxide was more complicated, giving substitution for halogen and the chloromethyl group at silicon as well as t-butyl methyl ether.
- Hopper, Steven P.,Tremelling, Michael J.,Goldman, Emma W.
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p. 247 - 256
(2007/10/02)
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