فهرست مطالب

Catalysis - Volume:6 Issue: 1, Winter 2016

Iranian Journal of Catalysis
Volume:6 Issue: 1, Winter 2016

  • تاریخ انتشار: 1394/08/02
  • تعداد عناوین: 13
|
  • Rajesh K. Singh, Shikha Sharma, Akshdeep Sandhar, Manpreet Saini, Sahil Kumar Pages 1-21
    1,5-benzodiazepines are regarded as one of the most important classes of heterocyclic compounds as privileged structures and have vast range of applications in the field of medicine and chemistry. They are therefore attractive synthetic targets for organic and medicinal chemist. The current review article mainly covers the multicomponent green chemistry approaches for the synthesis of 1,5-benzodiazepines. The review is organized systematically into types of catalysts used for the 1,5-benzodiazepines synthesis like silica supported catalysts, various Lewis acids, organoacids and miscellaneous catalysts. This article emphasizes on various heterogenous and homogenous catalysts used alongwith their yield and brief description of their mechanism of action. At the end of review, the entire catalysed are organized into tabulated form for quick at a glance review of various catalysts utilized with their yield and time taken for the synthesis.
    Keywords: 1, 5, Benzodiazepines, Multicomponent, Silica, supported catalysts, Organoacids, Catalysts
  • Bi Bi Fatemeh Mirjalili, Abdolhamid Bamoniri, Mohammad Ali Mirhoseini Pages 23-27
    The presence of an imidazole ring in natural products and pharmacologically active compounds has instituted a diverse array of synthetic approaches to these heterocycles. Very recently, we among many others have demonstrated that heterogeneous reagent systems have many advantages such as simple experimental procedures, mild reaction conditions and minimization of chemical wastes as compared to the liquid phase counterparts. Thus, inorganic acidic salts such as Al(HSO4)3, Mg(HSO4)2 and Zr(HSO4)4 could be recommended for above mentioned purposes. Al(HSO4)3 is an efficient, readily available and cheap catalyst for thesynthesis of 1,3-benzo[d]thiazole derivatives by condensation of 2-aminothiophenol and aldehydesunder sonication conditions.This protocol is very simple with easy workup and good to excellent yieldsof products.
    Keywords: 1, 3, Benzo[d]thiazole, Benzothiazoles, Al(HSO4)3, Aluminium hydrogen sulfate, 2, Aminotiophenol, Sonication conditions
  • Mostafa Feyzi, Gelareh Khajavi Pages 29-35
    In the present research work, the kinetics of sunflower oil transesterification reaction in the presence of Ba-Sr/ZSM-5 nanocatalyst which prepared using incipient wetness impregnation method was investigated. The 10wt.%Ba-Sr/ZSM-5 (Sr/Ba=3/2) nanocatalyst was calcined at 600 °C for 6 h with a heating rate of 3 ºC/min. The experimental conditions were the methanol/oil 9/1molar ratio, reaction time (0-180 min) and reaction temperature (323–333 K) with mechanical stirring of 500 rpm. An irreversible pseudo-second order kinetics was considered for triglyceride conversion from the best modeling of experimental data. From the kinetic study, Ea=67.03 kJ/mol and A=9.29×108 1/min were obtained. The yield of the methyl ester products (86.69%) were determined using gas chromatography–mass spectrometry. characterization of the catalysts and precursors was performed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-Ray diffraction (XRD), Transmission electron microscopy (TEM), and N2 adsorption-desorption measurement methods.
    Keywords: Biodiesel, Kinetics, Activation energy, Characterization, Operational conditions, Pseudo, second order
  • Bahar Khodadadi, Maryam Bordbar Pages 37-42
    In this paper, undopedZnO and Co-ZnOnano structureswith different molar ratio of Cobalt have been synthesized by the sonochemical method. Structure have been characterized by Fourier Transform (FTIR) and UV–Vis spectroscopy,Scanning Electron Microscopy (SEM), Energy Dispersive Analytical X-Ray (EDAX), and X-Ray Diffraction (XRD) methods. Moreover, the direct band gap has been calculated by Tauc’s approach.Moreover, mean crystal size has been estimated by Scherrerequaton. Furthermore, photocatalytic activity for all samples has been investigated under UV irradiation in an aqueous medium. Compared with pure ZnO, the band gap of the Co-ZnOhas been shown decrease and it is dependent on the content of dopants. Also, photocatalytic activity improves in the presence of cobalt dopant.
    Keywords: Sonochemical method, Band gap, Phptocatalytic activity, ZnO nanostructure
  • Bijan Mombeni Goodajdar, Soghra Soleimani Pages 43-49
    An atom-efficient, eco-friendly, solvent-free, high yielding, multicomponent green strategy to synthesize triazolo[1,2-a]indazole-triones derivatives by the one-pot condensation of aldehyde, dimedone, and phenyl urazole is presented. A series of different substituted aromatic aldehydes including either electron-withdrawing or electron-donating groups used in this reaction participated well and gave the corresponding products in good to excellent yield. Poly (ethylene glycol) based magnetic room temperature dicationic ionic liquid, PEG-MRTDIL, was prepared by mixing PEG-DIL with anhydrous FeBr3 under neat conditions. The catalyst was studied by UV and IR spectroscopy. This method provides several advantages such as environment benign, high yield, simple work up procedure and reusable catalyst.
    Keywords: One, pot, Urazole, Dimedone, Magnetic dicationic ionic liquid, Polyethylene glycol
  • Zahra Lasemi, Bahareh Sadeghi, Fereshteh Amiri Tavasoli Pages 51-55
    Nano silica sulfuric acid as a solid acid, was described to be an effective catalyst for one-pot three-component reaction of kojic acid, aryl aldehydes and indoles for the preparation of 2-substituted aryl (indolyl) kojic acid derivatives. The catalyst was prepared by combination of chlorosulfonic acid to nano silica gel. The size of nanoparticles were observed with SEM.All prepared compounds with melting points, 1H NMR and 13C NMR were characterized. High yields, simple operation, easy-work procedure, mild reaction conditions are some advantages of this protocol. The present method does not involve any hazardous organic solvent. Therefore, this procedure could be classified as green chemistry.
    Keywords: Kojic acid, Indole, Nano silica sulfuric acid, Aldehyde, Multi, component
  • Javad Safari, Leila Javadian Pages 57-64
    In this paper, Fe3O4-chitosan nanoparticles were prepared by the immobilization of chitosan on the surface of Fe3O4 nanoparticles. Then, the 5-substituted hydantoins were synthesized from the condensation of aldehyde derivatives, ammonium carbonate and zinc cyanide as a well-known cyanating agent by the magnetic Fe3O4-chitosan nanoparticles under neat conditions. Fe3O4-Chitosan nanocatalyst as a renewable hybrid catalyst was easily recovered by an external magnet and reused for 4 times without obvious drop in its catalytic activity. The purpose of this research was to provide an easy method for the synthesis of 5-substituted hydantoins in high yields and short reaction times by a robust and magnetic recoverable catalyst.
    Keywords: Fe3O4, Chitosan, Magnetic catalyst, Hydantoin, Zinc cyanide
  • Sahar Shokrollahi, Ali Ramazani, Seyed Jamal Tabatabaei Rezaei, Asemeh Mashhadi Malekzadeh, Pegah Azimzadeh Asiabi, Sang Woo Joo Pages 65-68
    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 that the optimum parameters for synthesis of HBIW were 5% mol with respect to glyoxal for catalyst, acetonitrile-water as solvent, 5 minutes as reaction time and 150 W for ultrasonic power. In general, improvement in rates and yields were observed when the reactions were carried out under sonication in comparison with classic conditions.
    Keywords: Hexabenzylhexaazaisowurtzitane (HBIW), Citric acid, Green chemistry, Ultrasound irradiation
  • Leila Khazdooz, Amin Zarei Pages 69-74
    An efficient, mild and environmentally friendly method was reported for the synthesis of An efficient, mild and environmentally friendly method was reported for the synthesis of pyranopyroles from aryl aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate in the presence of catalytic amounts of Methyl imidazolium hydrogen sulfate ([Hmim][HSO4]) as an efficient catalyst. These syntheses were performed via a one-pot four-component condensation in water/ethanol (50%) at 50 ◦C. This method easily provides the coresponding products in good yield and relatively short reaction times. Also the reusability of the catalyst was investigated, the catalyst could be employed four times, although its activity gradually decreased.
    Keywords: Four, component reaction, Pyranopyrazole, Aldehydes, Hydrazine hydrate, Methyl imidazolium hydrogen sulfate
  • Zinat Gordi, Mohammad Vazan Pages 75-80
    Substituted 2, 4- diphenyl quinolines were synthesized by a multicomponent domino reaction of anilines, aldehydes and terminal aryl alkynes. The synthetic pathway involves the formation of an imine, followed by the intermolecular addition of an alkyne to the imine. This intermediate immediately undergoes ring closure and oxidative aromatization. The reaction is catalyzed by natural kaolin, a strong, environmentally benign solid acid. In this procedure natural kaolin is used without any supporting. This catalyst- assisted microwave irradiation has oxidizing ability that leads to aromatization of final intermediate and produces the aromatic substituted quinolines without any other oxidizing agents. The multicomponent approach yields the products in excellent yields in a matter of minutes. The use of microwave activation reduces the reaction time significantly. No side-products are formed significantly. In addition one of the synthesized substituted quinolines is a new compound. However, this catalyst can be used for the synthesis of a variety of important heterocycles such as pyrrazoles, oxazolines, benzodiazepines and quinoxalines.
    Keywords: Kaolin, Heterogeneous catalyst, 2, 4, Disubstituted quinolines, Solvent, free
  • Seyed Ali Hosseini Pages 81-88
    LaMnO3 and LaMnO3/ZSM-5 nano catalysts were synthesized by Pechini method and their physical-chemical properties were characterized using XRD, FTIR, SEM-EDX, UV-vis DRS, BET surface area and TPR. The correlation between characteristic properties and activity of catalysts were investigated. The catalytic performance of the catalysts was evaluated in combustion of 2-propanol and compared with 1% Pt/Al2O3 performance. The results of SEM and UV-Vis DRS of LaMnO3/ZSM-5 indicated the well dispersion of the perovskite oxide on the support. The results of TPR indicated no direct correlation between the activity and reducibility of the catalysts. The catalytic studies revealed that the supporting of LaMnO3 increased the conversion rate of 2-propanol, which is ascribed to higher surface area, more availability of catalytic sites to probe molecules. In addition, the stability of LaMnO3/ZSM-5 was higher than that of LaMnO3 during a 10 h time on stream. The conversion rate of 2-propanol on the LaMnO3/ZSM-5 was higher even than that on the industrial 1%Pt/Al2O3 catalyst. The study showed that the perovskite/zeolite catalyst could be promising catalysts in the removal of VOCs.
    Keywords: Nano perovskite, Conversion rate, Catalytic combustion, UV, Vis DRS, 2, Propanol
  • Surekha N. Deshmukh, Jitendra B. Gujar, Ramrao A. Mane, Murlidhar S. Shingare Pages 89-94
    A rapid and efficient one-pot, four-component protocol towards the synthesis of polyhydroquinoline derivatives has been developed. The condensation of aldehyde, dimedone, ethyl acetoacetate and ammonium acetate in presence of stannous chloride was carried out under solvent free condition to synthesize a variety of polyhydroquinoline derivatives in good to excellent yields. Stannous chloride was proved to be an efficient heterogeneous Lewis acid catalyst, which could be relatively non-toxic, inexpensive, possess good thermal stability and easy to handle. The present method provides several advantages such as mild reaction conditions, green methodology, inexpensive catalyst, simple work-up procedure, short reaction time and high yields.
    Keywords: Polyhydroquinoline, Stannous chloride, One, pot synthesis, Solvent, free conditions
  • Javad Afsar Pages 95-97
    Javad Afsar was born in 1988 in Hamedan, Iran. He obtained his B.Sc. (2011) and M.Sc. in Organic Chemistry (2013) from Bu-Ali Sina University, Hamedan, Iran. Currently, he is working towards his Ph.D. under the supervision of Prof. Mohammad Ali Zolfigol and Prof. Ardashir Khazaei at the same university. His research involves design, Synthesis and applications of new catalyst in organic synthesis.