نتایج جستجو برای: green catalyst
تعداد نتایج: 182077 فیلتر نتایج به سال:
nanomagnetite-fe3o4 is used as a highly efficient, mild, green and recyclable nanomagnetite catalyst for the synthesis of 4,4´-(arylmethylene)-bis(3-methyl-1-phenyl-1h-pyrazol-5-ol) derivatives in solvent-free conditions. the condensation reaction of 3-methyl-1-phenyl-1h-pyrazol-5(4h)-one with aromatic aldehydes affords the title compounds in high yields and short reaction times. the nanocataly...
cuo-ceo2 nanocomposite is reported as a green and highly efficient recyclable catalyst for the multicomponent synthesis of 3,4-dihydropyrimidin-2(1h)-ones/thiones under solvent-free conditions. the catalyst was synthesized by co-precipitation method and characterized by xrd, bet specific surface area, fesem and eds analysis.
in this study, an efficient and green process for the synthesis of dihydropyrimidin-2(1h)-ones from aromatic benzaldehydes, ethyl acetoacetate and urea using al-mcm-41 as heterogeneous catalyst and microreactor under solvent-free conditions has been developed. the advantages of this method are easy work-up procedure, regeneration of the catalyst, clean and neutral reaction conditions.
4-dodecylbenzenesulfonic acid (dbsa) has been shown to be an efficient, mild, green, stable and chemoselective brønsted acid catalyst for the synthesis of 1, 1-diacetates (acylals) of aldehydes under solvent-free conditions. the mild condition, eco-friendly, excellent yields, short reaction times and using an easily available, inexpensive and reusable catalyst are important features of this met...
A facile, green, and efficient method for the direct oxidative amination of benzoxazoles using heterocyclic ionic liquid as catalyst has been developed. The reaction proceeded smoothly at room temperature and gave the desirable 2-aminobenzoxazoles with good to excellent yields (up to 97%). The catalyst 1-butylpyridinium iodide can be easily recycled and reused with similar efficacies for at lea...
we wish to report a mild and efficient one-pot three-component reaction of an aryl aldehyde, malononitrile and barbituric acid or 4-hydroxycoumarinfor the synthesis ofpyrano[2,3-d]pyrimidine and dihydropyrano[c]chromene derivatives in the presence of iron ore pellet as a natural and reusable catalyst under heterogeneous and green conditions. the present methodology offers several advantages suc...
synthesis of 2,4,5-triaryl-1h-imidazoles using a potent, green and reusable nano catalyst (fhs/sio2)
a simple, green and efficient method for synthesis of 2,4,5-trisubstituted imidazoles is described via three-component cyclocondensation of benzil or benzoin, aldehyde and ammonium acetate by using the nano sio2-supported ferric hydrogen sulfate (fhs/sio2), as a catalyst, under solvent-free conditions. the nano sio2 support and catalyst were characterized by x-ray diffraction (xrd), transmissio...
the condensation of benzylamine with glyoxal leads to hexabenzylhexaazaisowurtzitane (hbiw) in acetonitrile solvent with citric acid as a green catalyst under both conventional stirring and ultrasonic irradiation conditions. the influence of four variables, including the amount of catalyst, solvent, reaction time and ultrasonic power, on the reaction yield was investigated. the results showed t...
a simple and green synthetic strategy to prepare bao/tio2-zro2 as a solid base catalyst was reported. these materials with various amounts of bao were prepared by the adsorption method. the physical and chemical properties of bao/tio2-zro2 were investigated by x-ray diffraction, x-ray fluorescence, specific surface area and bjh pore size distribution, ft-ir spectroscopy, scanning electron micro...
We designed a ceria-vanadia/silica (Ce-V/SiO2) heterogeneous catalyst and used it for the green and efficient synthesis of 2-amino-3-cyano-4H-pyran derivatives. The green reaction was a multicomponent one-pot condensation of 5,5-dimethylcyclohexane-1,3-dione, aromatic aldehyde, and malononitrile in an eco-compatible solvent (ethanol). The catalyst was synthesized and fully characterized by powd...
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