15842-76-9Relevant academic research and scientific papers
Copper-Free Double Silylation of 1,2-Dibromobenzenes Using a Mg/LiCl/DMI System
Kitamura, Tsugio,Yamada, Rin,Gondo, Keisuke,Eguchi, Nobuo,Oyamada, Juzo
, p. 2495 - 2500 (2017/05/22)
The reaction of 1,2-dibromobenzenes with chlorotrimethylsilane efficiently proceeded in the presence of Mg and LiCl in DMI under mild conditions, giving 1,2-bis(trimethylsilyl)benzenes in good to high yields. The reaction of 1,2-dibromobenzenes with chlorodimethylsilane under the same conditions afforded the corresponding 1,2-bis(dimethylsilyl)benzenes in high yields. Functional group transformations of 1,2-bis(trimethylsilyl)benzene were conducted to demonstrate the synthetic utility.
Synthesis of 1,2-bis(trimethylsilyl)benzene derivatives from 1,2-dichlorobenzenes using a hybrid metal Mg/CuCl in the presence of LiCl in 1,3-dimethyl-2-imidazolidinone
Kitamura, Tsugio,Gondo, Keisuke,Katagiri, Toshimasa
, p. 3421 - 3424 (2013/06/26)
A practical and safe synthesis of 1,2-bis(trimethylsilyl)benzene from 1,2-dichlorobenzene and Me3SiCl was achieved by use of a hybrid metal of Mg and CuCl in the presence of LiCl in 1,3-dimethyl-2-imidazolidinone (DMI). This method does not req
A convenient iron-catalyzed method for the preparation of 1,2-bis(trimethylsilyl)benzenes
Bader, Samuel L.,Kessler, Simon N.,Wegner, Hermann A.
experimental part, p. 2759 - 2762 (2010/10/05)
A convenient iron-catalyzed method for the preparation of 1,2-bis(trimethylsilyl)benzenes is presented. Compared to the current procedures, low temperatures and toxic solvents are avoided, allowing large-scale preparation. Additionally, a variety of subst
Remote trimethylsilyl groups interfering with the ortho deprotonation of fluoroarenes and chloroarenes
Heiss, Christophe,Marzi, Elena,Mongin, Florence,Schlosser, Manfred
, p. 669 - 675 (2007/10/03)
(2-Fluorophenyl)trimethylsilane (2-F) and (2-chlorophenyl)-trimethylsilane (2-Cl) react with sec-butyllithium or lithium 2,2,6,6-tetramethylpiperidide under permutational hydrogen/metal interconversion (metalation) more slowly than, respectively, the corr
meta- rather than ortho-directed metalations: Buttressing effects prejudicing the proton abstraction from (2,6-dihalophenyl)silanes
Heiss, Christophe,Cottet, Fabrice,Schlosser, Manfred
, p. 5236 - 5241 (2007/10/03)
(2,6-Dichlorophenyl)trimethyl- and -triethylsilane exhibit untypical reactivity patterns toward strong bases. When treated at -100°C with lithium 2,2,6,6-tetramethylpiperidide, they give rise to two, with sec- or tert-butyllithium even three, different organometallic intermediates which can be intercepted with standard electrophiles. The trialkylsilyl group intervenes in two respects. Exerting steric pressure on the neighboring chlorine atoms, it facilitates the permutational displacement of one of them against lithium, a side reaction which occurs whenever alkyllithium compounds are employed. At the same time it impedes the attack of hydrogen atoms by the base in the immediate vicinity of the halogens due to relay transmission of steric hindrance. As a consequence, deprotonation occurs preferentially or exclusively at the 5-("meta") rather than the 4-("ortho")position. 4-Lithiated species, generated as by-products or separately by permutational halogen/metal interconversion, eliminate lithium chloride at -75°C to set free didehydrobenzenes ("arynes") which are trapped by their aryllithium precursors. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
Multinuclear NMR spectroscopic studies of aryltrimethylsilanes and aryldimethylphosphaneboranes
Albanese, Joseph A.,Gingrich, Diane E.,Schaeffer, Charles D. Jr.,Coley, Suzanne M.,Otter, Julie C.,et al.
, p. 23 - 36 (2007/10/02)
Proton, boron-11, carbon-13, silicon-29, and phosphorus-31 NMR chemical shifts and coupling constants are reported for nine ortho- and 2,6-disubstituted aryltrimethylsilanes and five similarly substituted aryldimethylphosphaneboranes.Resonances in the natural-abundance carbon-13 NMR spectra for both sets of derivatives are assigned on the basis of additivity relationships, proton-coupled spectra, and relative magnitudes of 31P-13C)> coupling constants.Carbon-13 chemical shifts and 1J(13C-1H)> coupling constants indicate that the P(BH3)(CH3)2 group is electron-withdrawing.The 13C chemical shifts of aryl C(5) carbons can be attributed to steric inhibition of resonance of about the same magnitude as that produced by ortho-Si(CH3)3.Chemical shift and coupling constant data from previous work are expanded in terms of Taft's dual substituent constants ?1 and ?R0.Least squares solutions of these equations for aryldimethylphosphaneborane derivatives provide values of 0.41 for ?1 and 0.04 for ?R0 for the P(BH3)(CH3)2 group.These constants produce reasonable agreement wit observed 13C chemical shifts and coupling constants in the ortho derivatives.
Mechanism of Base-Catalyzed Desilylations of Aryl- and Heteroaryltrimethylsilanes
Effenberger, Franz,Spiegler, Wolfgang
, p. 3872 - 3899 (2007/10/02)
The influence of different bases on the cleavage of silicium-carbon bonds in aryl- and heteroaryltrimethylsilanes is investigated in the presence of benzaldehyde as electrophilic scavenger for the aryl and heteroaryl anions formed in this process.A reactivity gradation of the various basic catalysts employed is determined from the reactions with 2-(trimethylsilyl)benzothiazole (1).The increase of catalytic activity of the anions parallels that of their ion potential.Attack of the base at the Si atom is postulated as the first step in this reaction sequence, with subsequent dissociation of the pentacoordinated intermediate in the rate-determining step.The carbanion thus liberated rapidly reacts with benzaldehyde.In the differently substituted aryltrimethylsilanes 13, 13', and 13'' the dependency of aryl anion stability in the base-catalyzed carbodesilylation was investigated.The relative rates of reaction correlate with Hammett's ?-constants rather than with the corresponding aryl anion stabilities.
