نتایج جستجو برای: catalyst free reaction
تعداد نتایج: 924748 فیلتر نتایج به سال:
in this thesis, a better reaction conditions for the synthesis of spirobarbiturates catalyzed by task-specific ionic liquid (2-hydroxy-n-(2-hydroxyethyl)-n,n-dimethylethanaminium formate), calcium hypochlorite ca(ocl)2 or n-bromosuccinimide (nbs) in the presence of water at room temperature by ultrasonic technique is provided. the design and synthesis of spirocycles is a challenging task becaus...
the silica boron sulfuric acid nanoparticles (sbsans) as an efficient heterogeneous solid acid catalyst with both brønsted and lewis acidic sites catalyzed the preparation of bis-4-hydroxycoumarin derivatives using reaction of aldehydes and 4-hydroxycoumarin under mild and solvent-free condition at room temperature. this new and efficient methodology has advantages in comparison with currently ...
This article describe the applicability of 1,4-disulfopiperazine-1,4-diium chloride ([Piper-(SO3H)2].2Cl) as a green, versatile and Brönsted acidic ionic catalyst in the promotion of the synthesis of phthalazine derivatives via one-pot three component reaction between aromatic aldehydes, 1,3-diketone derivatives and phthalhydrazide under solvent-free reaction cond...
A convenient synthetic method for the synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetra substituted imidazole derivatives, has been developed via one-pot condensation reaction in solvent-free condition when aldehyde, ammonium acetate/amine, and 1,2-diketone are reacted using 0.8 mol% of NP-LaMnO3 at 80 °C under solvent free conditions. Catalyst could be recovered and reused in five reaction c...
A convenient synthetic method for the synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetra substituted imidazole derivatives, has been developed via one-pot condensation reaction in solvent-free condition when aldehyde, ammonium acetate/amine, and 1,2-diketone are reacted using 0.8 mol% of NP-LaMnO3 at 80 °C under solvent free conditions. Catalyst could be recovered and reused in five reaction c...
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...
an efficient, simple and convenient route is described for the synthesis of biscoumarin (3,3'-(arylmethylene) bis (4-hydroxy-2h-chromen-2-one)) by using of recyclable catalyst tio2@ksf. in this method, we synthesis biscoumarin derivatives via 3multi-component reactions (3mcrs) of two equivalent 4-hydroxycoumarin with one equivalent of aromatic aldehydes using 20 mg nano tio2@ksf as homogen...
This article describe the applicability of 1,4-disulfopiperazine-1,4-diium chloride ([Piper-(SO3H)2].2Cl) as a green, versatile and Brönsted acidic ionic catalyst in the promotion of the synthesis of phthalazine derivatives via one-pot three component reaction between aromatic aldehydes, 1,3-diketone derivatives and phthalhydrazide under solvent-free reaction cond...
In this research, (Carboxy-3-oxopropylamino)-3-propylsilylcellulose (COPAPSC) as an organocatalyst, has been synthesized by grafting of succinic anhydride on the NH2-modified cellulose (cellulose functionalized with 3- aminopropyltriethoxysilane). The –CO2H group-functionalized cellulose (COPAPSC) is used as a catalyst for the synthesis of coumarin derivatives from the reaction of phenolic subs...
a mild and efficient method has been developed for the preparation of substituted coumarins from reaction of various phenols with different β-ketoesters via pechmann condensation in the presence of brønsted acidic ionic liquid (n-(4-sulfonic acid) butyl triethylammonium hydrogen sulfate) as an effective catalyst under solvent-free conditions. different phenols reacted with ethyl acetoacetate to...
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