110577-10-1Relevant articles and documents
Geminal Di(hypersilyl) compounds - The synthesis and structure of bis[tris(trimethylsilyl)silyl]methanol
Gross, Thoralf,Kempe, Rhett,Oehme, Hartmut
, p. 1709 - 1714 (1997)
Tris(trimethylsilyl)silyllithium (1) reacts with methyl formate in diethyl ether (molar ratio 2:1) to give l,2-di(hypersilyl)ethylene 13. The formation of 13 proceeds through the intermediates formyl tris(trimethylsilyl)silane (4) and lithium bis[tris(trimethylsilyl)silyl]methoxide (5). In diethyl ether, the alkoxide 5 spontaneously eliminates lithium trimethylsilanolate thereby generating l,l-bis(trimethylsilyl)-2-[tris{trimethylsilyl)silyl]silene (9), which undergoes a formal [2+2] cycloaddition with the carbonyl compound 4 to afford 13. This was verified by crossover experiments. In pentane, the alkoxide 5 is moderately stable. Thus, the intermediate 5, prepared by reaction of 1 with tert-butyl formate in pentane, was protonated with water to give the di(hypersilyl)methanol 6 in good yield. The structure of 6 was elucidated by an X-ray crystal structure analysis, which expectedly revealed tremendous distortions of the molecular skeleton. Thus, the spatial demand of the two extended hemispherical (Me3Si)3Si groups forces a widening of the Si-C-Si angle at the central sp3 carbon atom to a value of 135.5°. WILEY-VCH Verlag GmbH, 1997.
Electron Donor-Acceptor Complex Enabled Decarboxylative Sulfonylation of Cinnamic Acids under Visible-Light Irradiation
Ge, Qian-Qian,Qian, Jia-Sheng,Xuan, Jun
, p. 8691 - 8701 (2019/08/30)
Visible-light-induced decarboxylative sulfonylation of cinnamic acids with aryl sulfonate phenol esters enabled by the electron donor-acceptor complex is developed. The method offers a mild and green approach for the synthesis of vinyl sulfones with excellent functional group compatibility under photocatalyst and oxidant-free conditions.
Allylsilanes in "tin-free" oximation, alkenylation, and allylation of alkyl halides
Rouquet, Guy,Robert, Frederic,Mereau, Raphael,Castet, Frederic,Landais, Yannick
, p. 13904 - 13911 (2012/01/15)
Tin-free oximation, vinylation, and allylation of alkyl halides have been developed by using allylsilanes as di-tin surrogates. Initiation of the radical process with a peroxide provides the silyl radical, which can abstract a halogen from the corresponding alkyl halide. The resulting carbon-centered radical then adds to various acceptors, including a sulfonyloxime, a vinylsulfone, and an allylsulfone, leading to formation of the desired products along with the corresponding allylsulfone resulting from the reaction of the PhSO2 radical with the allylsilane precursor. Better results were generally obtained with methallylsilane 1b than with 1a. This observation was rationalized by invoking the higher nucleophilicity of 1b and the faster β-fragmentation of the corresponding β-silyl radical intermediate. Calculation of the energy barrier for the β-fragmentation of a series of β-silyl radicals at the DFT level supported this hypothesis. Finally, a second version of these oximation and vinylation reactions, based on the utilization of 3-tris(trimethylsilyl)silylthiopropene, was devised, affording the desired oximes and olefins in reasonable yields. This strategy allowed the title reaction to be performed under milder conditions (AIBN, benzene, 80°C), as a result of the easier β-fragmentation of the C-S bond as compared with the C-Si bond.
