نتایج جستجو برای: reusable catalyst
تعداد نتایج: 53437 فیلتر نتایج به سال:
1,1-diacetates(acylals) were prepared by direct condensation of various aldehydes with acetic anhydride using dipyridine cobalt chloride (copy2cl2) as an efficient and green catalyst under solvent-free conditions at room temperature. the important features of this catalyst method are that the catalyst is solid, stable at high temperatures, soluble in water, stable in air, immiscible in common o...
A simple catalytic protocol for the synthesis of novel spiro[indoline-pyranodioxine] derivatives has been developed using ZnO nanoparticle as an efficient, green, and reusable catalyst. The derivatives are obtained in moderate to excellent yield by one-pot three-component reaction of an isatin, malononitrile/ethylcyanoacetate, and 2,2-dimethyl-1,3-dioxane-4,6-dione in absolute ethanol under con...
The 5-alkylthio and 5-arylthiotetrazoles were efficiently synthesized from thiocyanates using Fe3O4 nanoparticles as a magnetically recoverable and reusable catalyst. The main advantages allocated to this method are elimination of hydrazoic acid as a dangerous and harmful reagent, high yields and ease of product isolation. The catalyst can be simply recovered by an external magnet and reused wi...
Easy low-energy-cost preparation of a highly efficient and reusable single-atom-type structured catalyst for alkyne-to-alkene hydrogenation Suzuki coupling.
The Nano-CrY zeolite synthesized and characterized by Fourier transfer infrared (FT-IR), X-ray diffraction (XRD),and Scanning electron microscopy (SEM).The result show that nano catalyst prepared with mainly particles size about 30-80 nm .The XRD show the structure of the zeolite does not collapse. This Nano-CrY zeolite has been used as new, and nontoxic catalyst for catalyzes of synthesis of 2...
A simple and mild method for tetrahydropyranylation of alcohols is reported at room temperature using a catalytic amount of 3-methylimidazolinium hydrogensulfate([Hmim]HSO4) as a green, efficient and reusable catalyst. Using solvent-free conditions, non-toxic and inexpensive materials, modest and clean work-up, short reaction times and high yields of the products are the advantages o...
Silica sulfuric acid as an efficient and reusable heterogeneous catalyst has been used for the preparation of amidines 2 from formimidate 1 by reaction with aromatic amines at room temperature in good to excellent yields. Imidate was prepared by treatment of equimolar quantities of triethyl orthoformate and diaminomaleonitrile in refluxing dioxane. All the compounds were characterized fully by ...
Two simple protocols for the synthesis of 1, 2, 4, 5- tetrasubstitutedimidazoles using nano-SPA as a reusable, eco- friendly, inexpensive, and efficient catalyst are reported. Short reaction times, high yields, scale-up and easy workup are the advantages of these protocols.
A simple and efficient synthetic protocol has been developed for the synthesis of 3-substituted-2H-1,4-benzothiazines by using a novel sulfonic acid functionalized nano-γ-Al2O3 catalyst, devoid of corrosive acidic, and basic reagents. The developed method has the advantages of good to excellent yields, short reaction times, operational simplicity, and a recyclable catalyst. The catalyst can be ...
al-mcm-41 nanoreactors is found to be a remarkable efficient catalyst for one-pot multicomponent cyclocondensation of benzil, aniline or ammonium acetate and aromatic aldehydes for the synthesis of polysubstituted imidazoles under solvent-free conditions. the reaction was efficiently promoted by 10 mg nano-al-mcm-41 and the heterogeneous catalyst was recycled for four runs in this reaction with...
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