نتایج جستجو برای: brønsted acidic ionic liquid
تعداد نتایج: 285773 فیلتر نتایج به سال:
The most acidic OH groups in silica-aluminas (zeolites, clays, amorphous silica-aluminas) can be made to react selectively with C(6)D(6) to give acidic OD groups; quantification by IR spectroscopy shows that differences in the overall Brønsted acidity of aluminosilicates are dominated by differences in the density of sites of similar acid strength.
3-methyl-1-(4-sulfobuthyl)-1-h-imidazol-3ium hydrogen sulfate, as a dual acidic ionic liquid (dail), was found to be an efficient catalyst for the simple, rapid and green synthesis of substituted trisphenols from the condensation of different substituted phenols and 2,6-bis (methylol) phenols (bmp). dail catalyst efficiently promoted the reaction between phenols and bmps with a variety of funct...
Catalytic activities of eight sulfonic acid group functionalized ionic liquids in water were compared for the hydrolysis of Sigmacell cellulose (DP ~ 450) in the 150-180°C temperature range by measuring total reducing sugar (TRS) and glucose produced. The catalytic activity of acidic ionic liquids with different cation types decreases in the order imidazolium > pyridinium > triethanol ammonium ...
An efficient, mild and environmentally friendly method was developed for the Strecker reaction to synthesize α-aminonitriles in the presence of methyl imidazolium hydrogen sulfate ([Hmim][HSO4]) as an efficient catalyst. These syntheses were performed via a one-pot three-component condensation of aldehydes (or ketones), amines, and trimethylsilyl cyanide under mild and solvent free c...
In a straightforward and fast protocol, a mixture of 1,3-dimethylimidazolium fluoride ([DMIM]F) and 1-butylimidazolium tetrafluoroborate ([Hbim]BF₄) efficiently catalyzed the reaction of epoxides with ketene silyl acetals (KSA) to give various γ-lactones under metal-free conditions. Diverse kinds of the desired γ-lactones were directly prepared with high regioselectivities and yields in a simpl...
Two different ionic liquids have been tested in the electrochemical fabrication of anodic porous alumina in an aqueous solution of oxalic acid. It was found that during galvanostatic anodization of the aluminum at a current density of 200 mA/cm2, addition of 0.5% relative volume concentration of 1-butyl-3-methylimidazolium tetrafluoborate resulted in a three-fold increase of the growth rate, as...
در این پایان نامه در راستای اهداف شیمی سبز از مایعات یونی به عنوان حلال و کاتالیست در واکنش های هسته دوستی و حلقه زایی استفاده شده است. ضمن اینکه به واکنش کلیک، واکنش چندجزیی و واکنش بدون حلال به منظور توجه به مسایل زیست محیطی پرداخته شده است. قابل بازیابی برای تهیه تری آزول ها از آزید های آلی و آلکین های انتهایی (i) در ابتدا، یک مایع یونی حاوی مس معرفی گردید که این کاتالیست در حلال های مخت...
DFT calculations have demonstrated that the unconventional bifunctional Brønsted-Lewis acid activation mode is generally applicable to a range of nucleophilic conjugate additions catalyzed by bicyclic guanidine catalysts. It competes readily with the conventional bifunctional Brønsted acid mode of activation. The optimal pro-nucleophiles for this unconventional bifunctional activation are acidi...
A rapid, green and efficient method for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthene derivatives through a one-pot condensation of 2-naphthol with various aromatic aldehydes in the presences of several acidic ionic liquids including [PSMIM]Cl, [BMIM]HSO4, [BMIM]Cl, [BMIM]Br, and [BMIM]BF4 as organocatalysts and task-specific acidic ionic liquids (AILs) under solvent-free conditions is desc...
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