搜索结果: 31-45 共查到“化学反应工程 catalyst”相关记录99条 . 查询时间(0.234 秒)
Silica-bonded N-propylpiperazine sodium n-propionate as recyclable catalyst for synthesis of 4H-pyran derivatives（图）
Silica-bonded n-propylpiperazine sodium n-propionate Heterogeneous solid base catalyst Aldehyde
2013/12/5
Silica-bonded N-propylpiperazine sodium n-propionate (SBPPSP) was found to act as an efficient solid base for the preparation of a series of 4H-benzo[b]pyran derivatives. SBPPSP was used as a recyclab...
Aldol condensations of a variety of different aldehydes and ketones under ultrasonic irradiation using poly(N-vinylimidazole) as a new heterogeneous base catalyst under solvent-free conditions in a liquid-solid system Nader Ghaffari Khaligha, Taraneh Mihankhahb（图）
Ultrasound-assisted reaction Liquid-solid system Poly(N-vinylimidazole) Aldol condensation, Solvent-free
2013/12/5
An ultrasound-assisted aldol condensation reaction has been developed for a range of ketones with a variety of aromatic aldehydes using poly(N-vinylimidazole) as a solid base catalyst in a liquid-soli...
Rice husk ash supported FeCl2·2H2O：A mild and highly efficient heterogeneous catalyst for the synthesis of polysubstituted quinolines by Friedländer heteroannulation（图）
Rice husk ash Supported FeCl2·2H2O, Quinolines 2-Amino benzophenone Solvent-free Friedlä nder heteoannulation
2013/12/5
Rice husk ash was used as a new, green, and cheap adsorbent for FeCl3. Characterization of the obtained reagent showed that rice husk ash supported FeCl2·2H2O was formed. This reagent is efficient at ...
Fe3O4 Nanoparticles as an Efficient and Magnetically Recoverable Catalyst for the Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones under Solvent-Free Conditions（图）
dihydropyrimidinones dihydropyrimidinthiones ferroferric oxide nanoparticle one-pot condensation solvent-free
2013/10/12
The catalytic activity of Fe3O4 nanoparticles (NPs) in a one-pot three component condensation reaction consisting of an aromatic aldehyde, urea or thiourea, and a β-dicarbonyl under solvent-free condi...
Tetrabutylammonium hexatungstate [TBA]2[W6O19]: Novel and reusable heterogeneous catalyst for rapid solvent-free synthesis of polyhydroquinolines via unsymmetrical Hantzsch reaction（图）
Heterogeneous catalysis Polyhydroquinolines Tetrabutylammonium hexatungstate
2013/9/26
A novel, efficient, and environmentally friendly method for the synthesis of polyhydroquinoline derivatives by a one-pot, four-component unsymmetrical Hantzsch condensation of dimedone, aldehydes, eth...
CoFe2O4 nanoparticles：An efficient heterogeneous magnetically separable catalyst for “click” synthesis of arylidene barbituric acid derivatives at room temperature（图）
Magnetically separable catalyst Arylidene barbituric acid derivative Aqueous ethanol Superparamagnetic CoFe2O4 nanoparticle Heterogeneous catalyst
2013/9/25
A coprecipitation method was used to synthesize superparamagnetic CoFe2O4 nanoparticles without using any capping agents/surfactants. The prepared nanoparticles were characterized using Fourier transf...
Magnetically recoverable, nanoscale-supported heteropoly acid catalyst for green synthesis of biologically active compounds in water（图）
Core-shell particle Magnetically recoverable catalyst Heteropoly acid Xanthene Hydroacridine
2013/9/25
12-Tungstophosphoric acid supported on aerosil silica and silica-coated γ-Fe2O3 nanoparticles was prepared and characterized using transmission electron microscopy, scanning electron microscopy, and i...
In situ generated acylimidazolium acetate as an efficient catalyst and acylating agent for the acetylation of alcohols, phenols, and amines at ambient temperature（图）
Acetylation Acylimidazolium acetate Imidazole Ionic liquid
2013/9/25
Acylimidazolium acetate was readily prepared in situ from the reaction of imidazole with acetic anhydride and subsequently acted as a catalyst and acylating agent for the efficient acetylation of alco...
{[K.18-Crown-6]Br3}n：A tribromide catalyst for the catalytic protection of amines and alcohols（图）
{[K.18-Crown-6]Br3}n Trimethylsilylation Tetrahydropyranylation Alcohol Organic tribromide N-boc protection of amine
2013/9/25
{[K.18-Crown-6]Br3}n, a unique tribromide-type catalyst, was utilized for the N-boc protection of amines and trimethylsilylation (TMS) and tetrahydropyranylation (THP) of alcohols. The method is gener...
Dehydration of xylose to furfural using a Lewis or Brönsted acid catalyst and N2 stripping（图）
Lewis acid, Brö nsted acid Reaction mechanism Xylose dehydration Furfural Nitrogen stripping
2013/9/26
The activity of Lewis (Nb2O5) and Brönsted (Amberlyst 70) acid catalysts for the cyclodehydration of xylose to furfural was studied. The nature of the acidity resulted in significant changes in t...
Combustion-derived CuO nanoparticles: An effective and environmentally benign catalyst in the synthesis of aromatic nitriles from aromatic aldehydes（图）
Copper oxide, Nanoparticle Solution combustion'Nitrile Aldehyde, Hydroxyl amine
2013/9/27
CuO nanoparticles were synthesized using an energy-efficient and rapid solution combustion technique with malic acid employed as a fuel. The combustion-derived CuO nanoparticles were used as catalysts...
A succinimide-N-sulfonic acid catalyst for acetylation reactions in absence of a solvent（图）
Succinimde-N-sulfonic acid Protection Acetylation Chemoselective reaction Solvent-free condition
2013/9/27
A small amount of succinimide-N-sulfonic acid efficiently catalyzed the acetylation of a variety alcohols, phenols, thiols, amines and aldehydes with acetic anhydride at room temperature under solvent...
1,3,5-Tris(hydrogensulfato) Benzene: A New and Efficient Catalyst for Synthesis of 4,4'-(arylmethylene)bis(1H-pyrazol-5-ol) Derivatives（图）
1,3,5-trisbenzene aromatic aldehydes 1-phenyl-3-methylpyrazol-5-one 4,4'-bis ethanol multicomponent reaction
2013/10/4
1,3,5-Tris(hydrogensulfato) benzene (THSB) was easily prepared by the reaction between phloroglucinol and chlorosulfonic acid in dichloromethane at room temperature. This compound was then used as an ...
Silica-Bonded N-Propylpiperazine Sodium n-Propionate as Recyclable Basic Catalyst for Synthesis of 3,4-Dihydropyrano[c]chromene Derivatives and Biscoumarins（图）
silica-bonded N-propylpiperazine sodium n-propionate silica-bonded N-propylpiperazine methyl n-propionate aromatic aldehydes 3,4-dihydropyrano[c]chromenes biscoumarins
2013/10/4
A simple and efficient procedure for the preparation of silica-bonded N-propylpiperazine sodium n-propionate (SBPPSP) by the hydrolysis of silica-bonded N-propylpiperazine methyl n-propionate (SBPPMP)...
Nano-Fe3O4 Encapsulated-Silica Particles Bearing Sulfonic Acid Groups as a Magnetically Separable Catalyst for Highly Efficient Knoevenagel Condensation and Michael Addition Reactions（图）
magnetic nanoparticle silica Knoevenagel condensation Michael addition cyclic diketone
2013/10/4
Sulfonic acid-functionalized silica-coated nano-Fe3O4 particles (Fe3O4@SiO2-SO3H) have been prepared as a novel heterogeneous acid using a facile process. The material was subsequently identified as a...