6689-38-9Relevant articles and documents
Use of Silylated Formiates as Hydrosilane Equivalents
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Paragraph 0514, (2021/09/26)
The present invention relates to a method for preparing organic compounds of formula (I) by reaction between a silylated formiate of formula (II) and an organic compound in the presence of a catalyst and optionally of an additive. The invention also relates to use of the method for preparing organic compounds of formula (I) for the preparation of reagents for fine chemistry and for heavy chemistry, as well as in the production of vitamins, pharmaceutical products, adhesives, acrylic fibres, synthetic leathers, and pesticides.
Regioselectivity of Hydroxyl Radical Reactions with Arenes in Nonaqueous Solutions
Moores, Lee C.,Kaur, Devinder,Smith, Mathew D.,Poole, James S.
, p. 3260 - 3269 (2019/03/11)
The regioselectivity of hydroxyl radical addition to arenes was studied using a novel analytical method capable of trapping radicals formed after the first elementary step of reaction, without alteration of the product distributions by secondary oxidation processes. Product analyses of these reactions indicate a preference for o- over p-substitution for electron donating groups, with both favored over m-addition. The observed distributions are qualitatively similar to those observed for the addition of other carbon-centered radicals, although the magnitude of the regioselectivity observed is greater for hydroxyl. The data, reproduced by high accuracy CBS-QB3 computational methods, indicate that both polar and radical stabilization effects play a role in the observed regioselectivities. The application and potential limitations of the analytical method used are discussed.
Activation of hexamethyldisilazane (HMDS) by TiO2 nanoparticles for protection of alcohols and phenols: the effect of the catalyst phase on catalytic activity
Azad, Alireza,Dekamin, Mohammad G.,Afshar, Shahrara,Tadjarodi, Azadeh,Mollahosseini, Afsaneh
, p. 2951 - 2963 (2018/04/11)
Anatase TiO2 nanoparticles (TiO2 NPs) were synthesized by the sol–gel method using titanium tetra-isopropoxide (TTIP), isopropyl alcohol, and distilled water and then calcined at 400?°C for 3?h. X-ray diffraction and scanning electron microscopy methods, and Fourier transform infrared spectroscopy were used for characterization of the obtained TiO2 NPs. The obtained anatase TiO2 NPs were used as heterogeneous catalyst for trimethylsilation of various alcohols or phenols with hexamethyldisilazane (HMDS) in CH3CN at room temperature. High to quantitative yields of the products were obtained within short reaction times at room temperature using a very low loading of pure TiO2 NPs without any post-modification with Bronsted or Lewis acid species such as ClSO3H or HClO4. The catalyst can be recycled at least three times without significant loss of its activity. The results of this study provide evidence that the pure anatase phase of TiO2 exhibits higher catalytic activity in terms of catalyst loading and required reaction time compared to a mixture of anatase and rutile phases found in the commercial samples for trimethylsilation of various alcohols or phenols with HMDS.
Application of a novel nano-immobilization of ionic liquid on an MCM-41 system for trimethylsilylation of alcohols and phenols with hexamethyldisilazane
Zolfigol, Mohammad Ali,Sajjadifar, Sami,Ghorbani-Choghamarani, Arash,Tami, Farzaneh
, p. 7093 - 7106 (2018/08/17)
3-[(3-(Trisilyloxy)propyl)chloride]-1-methylimidazolium tribromide ionic liquid supported on MCM-41 [nano-MCM-41@(CH2)3-1-methylimidazole]Br3 as a novel heterogeneous nano-catalyst was easily prepared and characterized usi
Magnetic nanoparticle-supported DABCO tribromide: A versatile nanocatalyst for the synthesis of quinazolinones and benzimidazoles and protection/deprotection of hydroxyl groups
Rostami, Amin,Pourshiani, Omid,Navasi, Yahya,Darvishi, Neda,Saadati, Shaghayegh
, p. 9033 - 9040 (2017/08/29)
1,4-Diazabicyclo[2.2.2]octane tribromide supported on magnetic Fe3O4 nanoparticles (MNPs-DABCO tribromide) as a novel heterogeneous tribromide type compound was found to be an efficient and reusable nanocatalyst for the one-pot synthesis of 2-arylquinazolin-4(3H)-ones and 2-aryl-1H-benzo[d]imidazoles through oxidative cyclization of aldehydes with 2-aminobenzamides and 1,2-phenylenediamine, respectively. Also, MNPs-DABCO tribromide catalyzed trimethylsilylation/tetrahydropyranylation and desilylation/depyranylation of a wide variety of alcohols and phenols through changing the solvent medium at room temperature.
Silylation of O-H bonds by catalytic dehydrogenative and decarboxylative coupling of alcohols with silyl formates
Chauvier, Clément,Godou, Timothé,Cantat, Thibault
supporting information, p. 11697 - 11700 (2017/11/03)
The silylation of O-H bonds is a useful methodology in organic synthesis and materials science. While this transformation is commonly achieved by reacting alcohols with reactive chlorosilanes or hydrosilanes, we show herein for the first time that silylformates HCO2SiR3 are efficient silylating agents for alcohols, in the presence of a ruthenium molecular catalyst.
TENOFOVIR PRODRUG AND PHARMACEUTICAL USES THEREOF
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Paragraph 0036, (2015/07/15)
The invention relates to a tenofovir prodrug and pharmaceutical uses thereof. In particular, the invention relates to a compound as shown in general formula (I) and its isomer, pharmaceutically acceptable salt, hydrate or solvate, as well as their uses in
Selective silylation of alcohols, phenols and oximes using N-chlorosaccharin as an efficient catalyst under mild and solvent-free conditions
Aghapour, Ghasem,Moghaddam, Ali Kazemi,Nadali, Samaneh
, p. 197 - 203 (2015/05/12)
Efficient silylation of OH group in alcohols, phenols and oximes is described using a catalytic amount of N-chlorosaccharin and hexamethyldisilazane (HMDS) under mild and solvent-free conditions. This silylation reaction can be carried out with excellent and interesting various selectivities.
Polystyrene-gallium trichloride complex: A mild, highly efficient, and recyclable polymeric lewis acid catalyst for chemoselective silylation of alcohols and phenols with hexamethyldisilazane
Rahmatpour, Ali,Vakili, Ali,Azizian, Setare
, p. 443 - 451 (2013/12/04)
Polystyrene-supported gallium trichloride (PS/GaCl3) as a highly active and reusable heterogeneous Lewis acid effectively activates hexamethyldisilazane (HMDS) for the efficient silylation of alcohols and phenols at room temperature. In this he
Br?nsted acid-controlled [3 + 2] coupling reaction of quinone monoacetals with alkene nucleophiles: A catalytic system of perfluorinated acids and hydrogen bond donor for the construction of benzofurans
Hu, Yinjun,Kamitanaka, Tohru,Mishima, Yusuke,Dohi, Toshifumi,Kita, Yasuyuki
, p. 5530 - 5543 (2013/07/26)
We have developed an efficient Br?nsted acid-controlled strategy for the [3 + 2] coupling reaction of quinone monoacetals (QMAs) with nucleophilic alkenes, which is triggered by the particular use of a specific acid promoter, perfluorinated acid, and a solvent, fluoroalcohol. This new coupling reaction smoothly proceeded with high regiospecificity in regard with QMAs for introducing π-nucleophiles to only the carbon α to the carbonyl group, thereby providing diverse dihydrobenzofurans and derivatives with high yields, up to quantitative, under mild conditions in short reaction times. The choice of Br?nsted acid enabled us to avoid hydrolysis of the QMAs, which gives quinones, and the formation of discrete cationic species from the QMAs. Notably, further investigations in this study with regard to the acid have led to the findings that the originally stoichiometrically used acid could be reduced to a catalytic amount of 5 mol % loading or less and that the stoichiometry of the alkenes could be significantly improved down to only 1.2 equiv. The facts that only a minimal loading (5 mol %) of perfluoroterephthalic acid is required, readily available substrates can be used, and the regioselectivity can be controlled by the acid used make this coupling reaction very fascinating from a practical viewpoint.