18157-17-0Relevant articles and documents
Silicon-29 NMR spectra of trimethylsilylated alcohols
Kvicalova, Magdalena,Cermak, Jan,Blechta, Vratislav,Schraml, Jan
, p. 816 - 820 (2007/10/03)
29Si NMR spectra of trimethylsilyl (TMS) derivatives of 26 simple alcohols were measured under standardized conditions (i.e., in sufficiently diluted deuteriochloroform solutions). Due to association with the solvent the chemical shifts are in almost all cases larger than those reported earlier for different solutions. This observation is in agreement with the proposed mechanism of steric effects as being due to sterically controlled association with the solvent. The use of chloroform as a solvent enhances steric effects hut at the same time it can reduce small differences due to polar effects in closely related compounds. In the studied class of compounds the gross dependence of the chemical shift on polar effects is not substantially affected by the change of the solvent.
The thermolysis of ε-halodisilanes: A preference for 1,2-Si Si→O rearrangement or Si-O cleavage over Si=O bond formation
Roos, Christopher,McGibbon, Graham A.,Brook, Michael A.
, p. 1470 - 1479 (2007/10/03)
Tris(trimethylsilyl)-2,2,2-trifluoroethoxysilane 6, tris(trimethylsilyl)-2-fluoroethoxysilane 7, and tris(trimethylsilyl)-2-chloroethoxysilane 8 were synthesized and characterized by 1H, 13C and 29Si NMR, IR spectroscopy, and EI and CI mass spectrometry. Thermodynamic considerations would suggest that, as a result of the driving force provided by the formation of a Si-F or Si-Cl bond, the thermolyses of these compounds would lead to the formation of bis(trimethylsilyl)silanone 4. To examine this question, gas chromatography - mass spectrometry was as used a detection technique for products resulting from the high-pressure thermolyses of 6-8. The elimination of (Me3Si)3SiCl appears to be the major thermolytic pathway of decomposition for 8 at ambient or higher pressures, although it is accompanied by the formation of other products, some of which could have arisen from the addition of various halosilanes to a silanone. Neither 6 nor 7 thermolyzed cleanly; the former compound was essentially unreactive under the thermolysis temperatures used (850°C). Of the products produced in the thermolysis of 7, no evidence for the formation of the silanone was obtained. Independently, mass spectrometry was used to study unimolecular reactions of molecular ions derived from 6-8. The major route to solitary ions appears to involve a 1,2-trimethylsilyl migration from Si to O (9→10) prior to decomposition, for example, of the m/z 346 parent ion in the decomposition of 6. The preparation of the ionized silanone may be a minor pathway. Some of the other fragmentation pathways for 6-8 are discussed.
PROTECTION OF ALCOHOLS AND ACIDS WITH ALLYLSILANES CATALYZED BY IODINE OR IODOTRIMETHYLSILANE IN CHLORINATED HYDROCARBON
Hosomi, Akira,Sakurai, Hideki
, p. 85 - 88 (2007/10/02)
Many triorganosilyl ethers and esters were prepared by the reaction of allylsilanes with alcohols catalyzed by iodine or iodotrimethylsilane in excellent yields.Bromine and bromotrimethylsilane were also effective catalysts.
CHLOROETHOXY(TRIMETHYL)SILANE : A HARD-BASE TRAP WHICH PRESERVES TMS ETHER GROUPS AND IMPROVES THE WITTIG METHYLENATION OF GIBBERELLINS
Mander, Lewis N.,Turner, John V.
, p. 4149 - 4152 (2007/10/02)
A reagent, 2-chloroethoxy(trimethyl)silane (CETS), has been devised which ensures the preservation of TMS ether groups during Wittig methylenation in protic media and which makes this formerly capricious reaction with 16-keto gibberellins a reliable and straightforward procedure.
