Showing papers in "The Open Catalysis Journal in 2010"
TL;DR: In this paper, H-Indazolo(2,1-b)phthalazine-1,6,11(13H)-trione derivatives were synthesized in a simple and efficient method from the three-component condensation reaction of phthalhydrazide, dimedone, and aromatic aldehydes by H3PW12O40 in ionic liquid in good to excellent yields and short reaction times.
Abstract: H-Indazolo(2,1-b)phthalazine-1,6,11(13H)-trione derivatives were synthesized in a simple and efficient method from the three-component condensation reaction of phthalhydrazide, dimedone, and aromatic aldehydes by H3PW12O40 in ionic liquid in good to excellent yields and short reaction times. The ionic liquid 1-butyl-3- methylimidazolium tetrafluoroborate ((bmim)BF4) offered the best results in terms of yield of the products. It was observed that a homogeneous reaction medium proved beneficial for the yield of the reaction.
48 citations
17 citations
TL;DR: A series of novel 1,3,5-triaryl-2-pyrazoline derivatives has been synthesized by the reaction of chalcone and phenylhydrazine in high yields as discussed by the authors.
Abstract: A series of novel 1,3,5-triaryl-2-pyrazoline derivatives has been synthesized by the reaction of chalcone and phenylhydrazine in high yields. The structures of compounds obtained were determined by IR and 1 H NMR spectra.
17 citations
TL;DR: Dowex-50W-hyodrgen ion exchange resin was used as a reusable catalyst for the synthesis of oxazoline, imidazoline and thiazoline derivatives as discussed by the authors.
Abstract: Dowex-50W-hyodrgen ion exchange resin was used as a reusable catalyst for the synthesis of oxazoline, imidazoline and thiazoline derivatives through condensation reaction between arylnitriles and 2-aminoalcohol, ethylenediamine or 2-aminoethanthiol. This process provides several advantages such as excellent yields of the products, simple operation, convenient separation and inexpensive and recyclable catalyst.
16 citations
TL;DR: In this paper, a simple and efficient method was developed for the conjugate addition of a variety of aliphatic and aromatic amines to electron deficient alkenes in the presence of a catalytic amount of manganese (II) chloride in methanol-water to produce the corresponding -amino derivatives in excellent yields at room temperature.
Abstract: A simple, general and efficient method has been developed for the conjugate addition of a variety of aliphatic and aromatic amines to electron deficient alkenes in the presence of a catalytic amount of manganese (II) chloride in methanol-water to produce the corresponding -amino derivatives in excellent yields at room temperature.
15 citations
TL;DR: In this article, the performance of Pd-Ni composite electrodes was investigated in the case of methanol, ethanol, ethylene glycol, and glycerol in 1 M KOH at 25°C and showed that adding Ni from 1 to 20% to the pure Pd electrode increases the electrocatalytic activity for each alcohol showing maximum with 10% Ni.
Abstract: Nanostructured (100-x)% Pd -x % Ni (x = 1, 2, 5, 10, and 20) and (90 – y)%Pd-10%Ni-y%C (y = 0.5, 1, 2, 5, and 10) composite films are obtained on glassy carbon electrodes and characterized by XRD, TEM, cyclic voltammetry and chronoamperometric techniques for use as electrocatalysts towards methanol, ethanol, ethylene glycol and glycerol oxidations in 1 M KOH at 25°C. Results show that addition of Ni from 1 to 20% to the pure Pd electrode increases the electrocatalytic activity for electrooxidation of each alcohol showing maximum with 10% Ni. Further, all the Pd-Ni composite electrodes exhibit better electrocatalytic performance in the case of ethanol electrooxidation. The rate of electrooxidation of different alcohols on the active 90%Pd-10 % Ni electrode at E = -0.20 V in 1 M KOH is observed to follow the order: ethanol > methanol> ethylene glycol > glycerol. Incorporation of C from 0.5 to 10% to the active Pd10% Ni composite improves the electrocatalytic performance of the electrode further, the magnitude of improvement being greatest with 5%C. The apparent electrocatalytic activity of the active 90%Pd-10%Ni electrode at E = -0.20 V is enhanced ~ 1.3 to 2.1 times with introduction of 5%C.
13 citations
TL;DR: In this article, a 2-naphthylazo-p-methylphenolate ligand was used for transfer hydrogenation of alkyl and aryl ketones in the presence of 2-propanol and KOH.
Abstract: Recyclable (� 6 -p-cymene)-ruthenium(II) 2-naphthylazo-p-methylphenolate catalyst of formulation (RuCl( 6 -p- cymene)(L)) (where L = mono anionic 2-naphthylazo-p-methylphenolate ligand) is shown to be an efficient catalyst for transfer hydrogenation of a wide range of alkyl and aryl ketones in the presence of 2-propanol and KOH.
11 citations
11 citations
Journal Article•
TL;DR: An efficient and green procedure for the synthesis of 2, 4, 6-triaryl-1H-imidazole in polyethylene glycol under microwave irradiation in excellent yield has been developed.
Abstract: An efficient and green procedure for the synthesis of 2, 4, 6-triaryl-1H-imidazole in polyethylene glycol under microwave irradiation in excellent yield has been developed. Polyethylene glycol is non toxic, reusable, inexpensive and easily available.
10 citations
TL;DR: In this article, a simple and efficient approach towards one step synthesis of 6-amino-5-cyano-4-phenyl-2-mercapto pyrimidine and its hydroxyl derivatives was developed by three component condensation of aromatic aldehydes.
Abstract: A simple and efficient approach towards one step synthesis of 6-amino-5-cyano-4-phenyl-2-mercapto pyrimidine and its hydroxyl derivatives have been developed by three component condensation of aromatic aldehydes, malononitrile and thiourea/urea in presence of phosphorus pentoxide (Scheme 1).
10 citations
TL;DR: In this article, a simple and efficient method is developed for the zinc catalyzed Claisen rearrangement of allyl aryl ethers to o-allyl phenols by stirring in an oil-bath at 55 °C in liquid phase.
Abstract: A simple and efficient method is developed for the zinc catalyzed Claisen rearrangement of allyl aryl ethers to o-allyl phenols by stirring in an oil-bath at 55 °C in liquid phase. Moreover, zinc powder is re-cyclable up to six times use without much loss of significant activity. In addition to it, the products are obtained in good to excellent yields and are in a state of high purity. The structures of the products are confirmed by 1 H NMR, 13 CNMR, IR and mass spectral data and comparison with authentic samples prepared according to the literature methods.
Journal Article•
TL;DR: In this paper, the effect of carbon nanotubes on the electrocatalytic activity of binary nano-composites of Pt and nano-carbon (NC) was investigated.
Abstract: Binary nano-composites of Pt and nano-carbon (NC) and Pt and multiwalled carbon nanotube (MWCNT) have
been prepared with varied compositions ranging between 20 and 80wt% Pt and investigated them as electrocatalysts for
methanol oxidation. The study shows that with the increase in wt% of NC, the apparent electro-catalytic activity of the
composite catalyst increases initially, reaches maximum at about 40wt% NC and decreases thereafter. However, the
anodic peak current value, estimated as per mg of Pt present in the composite, increases gradually with increasing wt% of
NC in the composite. The electrochemical active surface area (EASA) value for Pt in the composite electrode also
increases with increasing the carbon composition in the composite. Almost similar effect of the MWCNT addition on the electro-catalytic activity is also observed in the case of Pt-MWCNT composite. Results have shown that an incorporation of carbon (NC/MWCNT) improves both the geometrical as well as the electronic properties of Pt.
Journal Article•
TL;DR: In this paper, a simple general and efficient method was developed for the conjugate addition of a variety of aliphatic and aromatic amines to electron deficient alkenes in the presence of a catalytic amount of manganese (II) chloride in methanol-water to produce the corresponding amino derivatives in excellent yields at room temperature.
Abstract: A simple, general and efficient method has been developed for the conjugate addition of a variety of aliphatic and aromatic amines to electron deficient alkenes in the presence of a catalytic amount of manganese (II) chloride in methanol-water to produce the corresponding � -amino derivatives in excellent yields at room temperature.
TL;DR: In this paper, a gem-dithiolato-bridged rhodium (I) (Rh2(μ-S2CBn2)(cod)2) complex (cod = 1,5-cyclooctadiene, Bn2CS2 2� = 1.3-diphenyl-2,2-Dithiolatopropane) dissolved in toluene in the presence of monodentate phosphite P-donor ligand (P(OPh)3) under carbon monoxide/hydrogen (1
Abstract: This work focuses on the use of a gem-dithiolato-bridged rhodium(I) (Rh2(μ-S2CBn2)(cod)2) complex (cod = 1,5-cyclooctadiene, Bn2CS2 2� = 1,3-diphenyl-2,2-dithiolatopropane) dissolved in toluene in the presence of monodentate phosphite P-donor ligand (P(OPh)3) under carbon monoxide/hydrogen (1:1, syngas) atmosphere as an effective catalyst for hydroformylation of some olefins (oxo-reactions). The capability of this system to catalyze the hydroformylation of hex-1-ene, cyclohexene, 2,3-dimethyl-but-1-ene and 2-methyl-pent-2-ene and their quaternary mixture (synthetic naphtha) has been demonstrated. This innovative method to perform the in situ hydroformylation of the olefins present in naphthas to oxygenated products would be a promissory work for a future industrial catalytic process applicable to gasoline improving based on oxo-reactions. An important observation is that variation of CO/H2 pressure (6.8 34.0 atm), temperature (60 80 oC), reaction time (2 10 h), rhodium concentration ((1.0 1.8)x10 -3 mol/L) affect hydroformy- lation reaction rates. Optimal conversion to oxygenated products were achieved under (Rh) = 1.8 x10 -2 mol/L, P(CO/H2) = 34 atm (CO/H2 = 1:1) at 80 oC for 10 h.
TL;DR: In this article, the optimal conditions for crystallization were: dissolving temperature, 15°C, initial temperature in crystallization, 30°C; cooling temperature, 0°C and adding 1,2-propanediol as adjuvant agent with a volume ratio 0.2 of water solution.
Abstract: Cefradine crystallization was studied under different conditions. The optimal conditions for crystallization were: dissolving temperature, 15°C; initial temperature in crystallization, 30°C; cooling temperature in crystallization, 0°C; and adding 1,2-propanediol as adjuvant agent with a volume ratio 0.2 of water solution. The yield of cefradine crystallization is about 92% under these conditions. The purity of cefradine crystals is over 98% under the same conditions. The average size of cefradine crystal is 500 μm. The content of cefalexin in crystal is reduced to only 0.36%.
TL;DR: In this paper, the conversion of methane into higher hydrocarbons and aromatics on potassium doped modified zeolite Zr:Mo catalysts under non oxidizing conditions have been studied in a fixed bed catalytic reactor system at 450 0 C and at atmospheric pressure.
Abstract: The conversion of methane into higher hydrocarbons and aromatics on potassium doped modified zeolite Zr:Mo catalysts under non oxidizing conditions have been studied in a fixed bed catalytic reactor system at 450 0 C and at atmospheric pressure. The potassium addition reduces the formation of carbon during the catalytic reaction. This also results in the stability of the catalyst system and increased aromatics production. This is due to electronically modified active sites and increase in Bronsted acidity.
TL;DR: In this paper, the structural characteristics, surface and the catalytic properties of pure and variously doped solids were examined by using XRD, N2 adsorption at- 196°C and isopropanol conversion carried out at 140-280°C using a flow technique under atmospheric pressure.
Abstract: Mn2O3/Al2O3 system was prepared by the impregnation method using finely powdered Al(OH)3 and a calculated amount of Mn(NO3)2 dissolved in the smallest amount of distilled water followed by drying and calcination at 400-600°C. Six doped solids were prepared by impregnating powdered Al(OH)3 Solids with different amounts of Zn(NO3)2 or (NH4)6Mo7O24.4H2O followed by drying, then impregnating with Mn(NO3)2. The doped solids were calcined at 400-600°C. The dopant concentrations were 0.75, 1.5, and 3 mol% ZnO or MoO3. The structural characteristics, surface and the catalytic properties of pure and variously doped solids were examined by using XRD, N2 adsorption at- 196°C and isopropanol conversion carried out at 140-280°C using a flow technique under atmospheric pressure. The obtained results revealed that the pure solids investigated and those doped with 0.75 and 1.5mol% ZnO or MoO3 calcined at 500°C, consisted of a mixture of nanosized MnO2 (Pyrolusite) and Mn2O3 (Partridgeite phase) together with � -Al2O3. Increasing the calcination temperature of the variously doped solids to 600°C led to the complete conversion MnO2(Pyrolusite) to nanosized Mn2O3 (Partridgeite phase). The crystallite size of manganese oxide phases varied between 3 and 56 nm. All surface characteristics of the system investigated were much affected by calcination temperature and dopant concentration. Isopropanol conversion carried out over pure and doped system calcined at different temperatures proceeded via dehydration and dehydrogenation yielding propene and acetone, respectively. The activity and selectivity of the various solids were much affected by the reaction temperature, calcination temperature and dopant concentration.
Journal Article•
TL;DR: In this article, the effect of a range of operating variables such as the pressure, temperature and H2/CO molar feed ratio on the catalytic performance of fused catalyst was investigated.
Abstract: The catalyst containing 80%Co/20%Ce/15wt%SiO2 was prepared using fusion procedure and studied for the conversion of synthesis gas to light olefins. The effect of a range of operating variables such as the pressure, temperature and H2/CO molar feed ratio on the catalytic performance of fused catalyst was investigated. It was found that the best operating conditions are H2/CO=2/1, T=350˚C and P=2 bar. The results are interpreted in terms of the structure of active catalyst. Characterization of both precursor and calcined catalysts was carried out using Powder X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and BET surface area measurements.
TL;DR: In this article, the authors used a heterogeneous cobalt nickel (oxide) bimetallic catalyst for the polymerization of butadiene gas in toluene, n-hexane and ethanol in a Parr reactor system.
Abstract: The polymerization of butadiene was studied using heterogeneous cobalt nickel (oxide) bimetallic catalyst. The prepared catalyst was subjected to calcination at different temperatures. This treatment results in the formation of different phases with multiple oxidation states. The characterization of the catalyst was carried out by XRD, SEM, EDX, TGA, FTIR and TPR/TPD. The catalytic activity was studied for the polymerization of butadiene gas in toluene, n-hexane and ethanol in a Parr reactor system. The products obtained, were characterized by FTIR, GC/MS, 1 H and 13 C NMR spectroscopy, Laser Light Scattering (LLS) and GPC. The best activity was achieved on the catalyst sample calcined at 1173 K in ethanol solvent. The product contains aliphatic and aromatic carbonyl compounds and polybutadiene terminated by OH group. The GPC and LLS studies indicates that polydispersity of the products are in the narrow range and high molecular weight product. The study reflects that the catalytic reaction conditions, the calcinations temperatures which control the oxidation state, phase of the catalyst and stability of the catalyst are mainly responsible for the change in products selectivity.
Journal Article•
TL;DR: In this article, a new Pt-catalyst supported on mesoporous silica (Pt/MPS) and a stoichiometric amount of long-chain hydrocarbons as reducing agents for NOx purification was achieved.
Abstract: Perfect de-NOx over a wide temperature range above 170 °C was achieved using a new Pt-catalyst supported on mesoporous silica (Pt/MPS) and a stoichiometric amounts of long-chain hydrocarbons as reducing agents for NOx- purification. Kinetic investigation of the HC-SCR of lean NOx over Pt/MPS, Pt/alumina and Pt/zirconia showed that such a remarkable activity of Pt/MPS is due to a large frequency factor but not to activation energy. Acid-treatment of the supports increased the activities of the catalysts and generated new IR-peaks in the range 1000-1200 cm -1 , which suggests the support-effects on the catalyst-activities to be related to the special surface functional groups of the supports. The present HC-SCR must be very useful to remove diesel-NOx by means of pulse-injection of diesel fuel into the exhaust.
TL;DR: In this article, the vapour phase selective conversion of glycerol to acetol at normal atmospheric pressure in a fixed-bed micro reactor was investigated over SO4 2� and WOx promoted ZrO2 and M-ZrO 2 (M = Al2O3 or TiO2) solid acid catalysts.
Abstract: The vapour phase selective conversion of glycerol to acetol at normal atmospheric pressure in a fixed-bed micro reactor was investigated over SO4 2� and WOx promoted ZrO2 and M-ZrO2 (M = Al2O3 or TiO2) solid acid catalysts. The investigated sulfate and tungstate ion promoted zirconia-based catalysts were prepared by both coprecipitation and impregnation methods and calcined at 923 K. The synthesized catalysts were characterized by means of X-ray powder diffraction, X-ray photoelectron spectroscopy, BET surface area and ammonia temperature-programmed desorption methods. Characterization results suggest that SO4 2� promoter strongly influences the physicochemical properties of the support oxides than WOx. However, the WOx promoted catalysts exhibited better catalytic activity than SO4 2� promoted catalysts. Among various catalysts investigated, the WOx/Al2O3-ZrO2 catalyst exhibited stable catalytic activity with the highest glycerol conversion of 99% and acetol selectivity of 74%.
Journal Article•
TL;DR: In this article, a 2-naphthylazo-p-methylphenolate ligand was used for transfer hydrogenation of alkyl and aryl ketones in the presence of 2-propanol and KOH.
Abstract: Recyclable (� 6 -p-cymene)-ruthenium(II) 2-naphthylazo-p-methylphenolate catalyst of formulation (RuCl( 6 -p- cymene)(L)) (where L = mono anionic 2-naphthylazo-p-methylphenolate ligand) is shown to be an efficient catalyst for transfer hydrogenation of a wide range of alkyl and aryl ketones in the presence of 2-propanol and KOH.
TL;DR: In this paper, a tartaric acid was synthesized from R-(+)/S-(-)-ethylphenylamine by reacting with (2S,3S)-(+)/(2R,3R)-(-) dihydrobutanedioic acid.
Abstract: The � -ethylphenylamine tartaric acid salts 1a-1d were synthesized from R-(+)/S-(-)-� -ethylphenylamine by reacting with (2S,3S)-(+)/(2R,3R)-(-) dihydrobutanedioic acid. They were used as the catalysts in cyanosilylation of prochiral aldehydes to give the corresponding cyanohydrin trimethylsilyl ethers in moderate conversion at room
TL;DR: Trimethyl pyrazolium tetrafluoroborate room-temperature ionic liquid was prepared and employed for the selective oxidation of alkyl/benzyl alcohols using palladium acetate by stirring at room temperature in presence of air (oxygen from air) as discussed by the authors.
Abstract: Trimethyl pyrazolium tetrafluoroborate room-temperature ionic liquid was prepared and employed for the selective oxidation of alkyl/benzyl alcohols using palladium acetate by stirring at room-temperature in presence of air (oxygen from air). This green procedure gave products in moderate to good yields. Moreover, the synthesized 1,3,5- trimethylpyrazolium tetrafluoroborate ionic liquid could be recycled for at least three runs without the loss of significant activity.
Journal Article•
TL;DR: In this paper, a simple and efficient method is developed for the zinc catalyzed Claisen rearrangement of allyl aryl ethers to o-allyl phenols by stirring in an oil-bath at 55 °C in liquid phase.
Abstract: A simple and efficient method is developed for the zinc catalyzed Claisen rearrangement of allyl aryl ethers to o-allyl phenols by stirring in an oil-bath at 55 °C in liquid phase. Moreover, zinc powder is re-cyclable up to six times use without much loss of significant activity. In addition to it, the products are obtained in good to excellent yields and are in a state of high purity. The structures of the products are confirmed by 1 H NMR, 13 CNMR, IR and mass spectral data and comparison with authentic samples prepared according to the literature methods.
TL;DR: In this paper, Telechelic poly (propylene oxide) bismacromonomers bearing methyl acetate end groups, were prepared by cationic ring-opening polymerization of propylene oxide (PO), in the presence of Acetic anhydride, catalyzed by Maghnite-H + (Mag-H+ ), in bulk.
Abstract: Telechelic poly (propylene oxide) (PPO) bismacromonomers bearing methyl Acetate end groups, were prepared by cationic ring-opening polymerization of propylene oxide (PO), in the presence of Acetic anhydride, catalyzed by Maghnite-H + (Mag-H + ), in bulk. Mag-H + is a montmorillonite sheet silicate clay which was exchanged with protons. The influence of the amount of acetic anhydride and the reaction time on The polymerisation yield and molecular weight were studied. The products have been caracterized by Nuclear magnetic resonance ( 1 H-NMR).