- Mg/La mixed oxide as an efficient heterogeneous basic catalyst for synthesis of 2-aminothiophenes under microwave irradiation
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Microwave-assisted synthesis of 2-aminothiophenes via a Gewald reaction using a heterogeneous strong basic Mg/La mixed oxide catalyst is described.
- Moeinpour, Farid,Dorostkar, Nadieh,Vafaei, Majid
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- Ethylene diamine grafted nanoporous UiO-66 as an efficient basic catalyst in the multi-component synthesis of 2-aminithiophenes
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This study demonstrates ED-UiO-66 as a novel and effective solid nanoporous basic catalyst prepared through the amine grafting onto the pores of UiO-66. The manufactured nanoparticles were identified by FT-IR, XRD, TGA, FESEM, TEM, CHN and BET and the characterization results certified formation of a single phase nanoporous substance with the medium grain size less than 90?nm. The synthesized material was employed as an efficient catalyst for the preparation of 2-aminotiophenes through the Gewald method. This thermochemically stable nanocatalyst was environmentally safe, reusable and economic. Therefore, this methodology can be simply extended for industrial goals.
- Erfaninia,Tayebee,Dusek,Amini
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- Facile pathway for synthesis of two efficient catalysts for preparation of 2-aminothiophenes and tetrahydrobenzo[b]pyrans
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Abstract: We report here a new magnetically recyclable catalyst consisting of iron-substituted Keggin-type heteropolyacid (HPA) grafted on modified Fe3O4 nanoparticles. The synthesized hybrid nanomaterial exhibited the excellent catalytic efficiency in condensation reaction for the preparation of tetrahydrobenzo[b]pyrans under solvent-free conditions as well as in the synthesis of 2-aminothiophenes via Gewald reaction. It must be noted that, HPA supported magnetite nanoparticles catalyzed the preparation of tetrahydrobenzo[b]pyrans, whereas for Gewald reaction amine-functionalized magnetite nanoparticles acted as a catalyst. Different characterization techniques such as Fourier transform infrared (FT-IR), X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) were used to characterize the hybrid nanomaterial. The reusability of catalyst was affirmed by using in consecutive runs for five times. Performance of prepared catalyst was compared with the various previously reported catalysts; the newly synthesized catalysts found to be most efficient with regard to reaction time, yield and ease of catalyst separation. Graphical Abstract: [Figure not available: see fulltext.].
- Saadati-Moshtaghin, Hamid Reza,Zonoz, Farrokhzad Mohammadi
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p. 2195 - 2213
(2017/12/18)
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- Preparation of magnetically recyclable ZnFe2O4 nanoparticles by easy single-step co-precipitation method and their catalytic performance in the synthesis of 2-aminothiophenes
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In this work, a new synthetic route for the preparation of ZnFe2O4 nanoparticles through the chemical co-precipitation using Fe2+ and Fe3+ ions in an alkaline solution was developed. The synthesized nanoparticles were characterized by XRD, FTIR, SEM, ICP-MS, DRS, TGA, VSM and elemental analysis. Characterization results confirmed the formation of single ZnFe2O4 phase, with an average particle size of 40?nm and a high saturation magnetization of 34?emu g?1. The prepared material was employed as a catalyst for the synthesis of 2-aminotiophene derivatives through the Gewald reaction. This thermally and chemically stable nanocatalyst is environmentally benign, economical and reusable which can be easily recovered using an external magnet. Therefore, it appears that this methodology can be simply extended for industrial purposes.
- Erfaninia,Tayebee,Foletto,Amini,Dusek,Zonoz
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- INHIBITORS OF THE PD-1/PD-L1 PROTEIN/PROTEIN INTERACTION
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The present invention provides novel compounds of formula (I) that are useful as inhibitors of the PD-1/PD-L1 protein/protein interaction.
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- TiO2/nanoclinoptilolite as an efficient nanocatalyst in the synthesis of substituted 2-aminothiophenes
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TiO2/nanoclinoptilolite (TiO2/NCP) was prepared by the mediation of hexadecyltrimethylammonium (HDTMA) as surfactant and used as an effective heterogeneous nanocatalyst for the preparation of substituted 2-aminotiophenes. The modified HDTMA/NCP was impregnated with titanium(IV) chloride solution followed by calcination at 500?°C for 20?h. The obtained nanocomposite was characterized using Fourier transform infrared spectroscopy, field emission scanning electron microscopy, inductively coupled plasma optical emission spectroscopy and X-ray diffraction. Moreover, the prepared nanocomposite had high stability and recoverability under mild and solvent-free conditions.
- Javadi, Farzad,Tayebee, Reza,Bahramian, Bahram
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- Basic Ionic Liquid [bmIm]OH-Mediated Gewald Reaction as Green Protocol for the Synthesis of 2-Aminothiophenes
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A simple, efficient, and environmental friendly procedure was developed based on the Gewald reaction for the synthesis of 2-aminothiophenes using a basic ionic liquid [bmIm]OH as both catalyst and solvent. Besides being a green protocol, the method offers advantages of successful synthesis of a variety of alkyl, aryl, alkoxy, and alkylamino-2-aminothiophenes in good yields.
- Kaki, Venkata Rao,Akkinepalli, Raghuram Rao,Deb, Pran Kishore,Pichika, Mallikarjuna Rao
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p. 119 - 126
(2015/10/20)
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- First Gewald reaction ignited by sodium polysulfide: Greener ultrasound-promoted synthesis of substituted 2-aminothiophenes in the absence of catalyst
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In this paper, a modified and facile Gewald reaction triggered by sodium polysulfide in the absence of catalytic base was developed. This approach involves a one-pot ultrasound-irritated aqueous reaction between ketones or aldehydes, malononitrile, and sodium polysulfide, which are converted into the corresponding 2-aminothiophene derivatives in moderate to high yields. In comparison with conventional methods, the prominent features of this sonocatalyzed procedure are experimental simplicity, good functional group tolerance, atom efficiency, and the use of water as a green solvent.
- Liang, Chengyuan,Lei, Dong,Wang, Xiuzhen,Zhang, Qingqing,Yao, Qizheng
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p. 458 - 463
(2013/10/21)
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- KG-60-piperazine as a new heterogeneous catalyst for gewald three-component reaction
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Piperazine supported on amorphous silica (KG-60-piperazine) as a basic catalyst acts in the Gewald three-component reaction of some aldehydes and ketones with malononitrile as well as ethyl cyanoacetate. The catalyst shows general utility with a variety of starting carbonyl compounds. Moreover, the catalyst can be reused for four additional cycles without significant loss of the activity. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
- Rezaei-Seresht, Esmail,Tayebee, Reza,Yasemi, Mohammad
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p. 1859 - 1864
(2013/05/21)
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- Easy single-step preparation of ZnO nano-particles by sedimentation method and studying their catalytic performance in the synthesis of 2-aminothiophenes via Gewald reaction
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Zinc oxide is a multi-purpose active material with important catalytic applications. In this study, nano-sized ZnO particles were easily synthesized through sedimentation of zinc acetate di-hydrate in absolute ethanol and were characterized by XRD and SEM. The XRD results indicated pure wurtzite structure with the average particle size of 26.9 nm for the nano-particles. It was observed that size of ZnO nano-particles was decreased while solution concentration was increased. This observation would be explained considering enhancing nucleation processes of nano-particles at high concentration of zinc acetate. The prepared nano-particles (2.5 mol%) were used as catalyst for the fast and efficient synthesis of 2-aminothiophenes under solvent free conditions. The three-component mixture of a carbonyl compound, malonodinitrile, and elemental sulfur was converted into the corresponding 2-aminothiophene in moderate to high yields with excellent selectivity.
- Tayebee, Reza,Javadi, Farzad,Argi, Gholamreza
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- Synthesis of thieno[2,3-b]quinolinone derivatives
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The Knoevenagel reactions of malononitrile with acetophenone or 4-substituted acetophenons were carried to give the corresponding 2-(1-aryle thylidene)malononitriles, which was further cyclized with sulfur using NaHCO3 as catalysts to generate
- Han, Guang-Fan,Wang, Ming,Chen, Li-Zhuang,Hu, Xiao-Lei
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p. 909 - 912
(2012/10/29)
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- A facile and practical one-pot synthesis of multisubstituted 2-aminothiophenes via imidazole-catalyzed Gewald reaction
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A simple and efficient procedure was developed for the synthesis of multisubstituted 2-aminothiophene derivatives. In the presence of catalytic amount of imidazole, ketones or aldehydes, dicyanomethane and elemental sulfur were converted into the corresponding 2-aminothiophene derivatives in moderate to high yields in DMF at 60 °C.
- Huang, Xian-Gui,Liu, Jia,Ren, Jiangmeng,Wang, Tao,Chen, Weidong,Zeng, Bu-Bing
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experimental part
p. 6202 - 6205
(2011/09/19)
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- Microwave accelerated Gewald reaction: synthesis of 2-aminothiophenes
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Microwave-promoted synthesis of 2-aminothiophenes by multicomponent reactions of a ketone with an active nitrile and elemental sulfur under KF-alumina catalysis is described.
- Sridhar, Madabhushi,Rao, Rayankula Mallikarjuna,Baba, Nanduri H.K.,Kumbhare, Ravindra M.
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p. 3171 - 3172
(2007/10/03)
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- New conditions for the synthesis of thiophenes via the Knoevenagel/Gewald reaction sequence. Application to the synthesis of a multitargeted kinase inhibitor
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Novel conditions have been developed for the preparation of substituted 2-aminothiophenes employing the Knoevenagel condensation followed by the Gewald reaction. The benefits of these conditions are their mildness, and the ease of product isolation. Thus,
- Barnes, David M.,Haight, Anthony R.,Hameury, Thomas,McLaughlin, Maureen A.,Mei, Jianzhang,Tedrow, Jason S.,Riva Toma, Joan Dalla
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p. 11311 - 11319
(2007/10/03)
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- Synthesis of polyfunctionally substituted thiophene, thieno[2,3-b]pyridine and thieno[2,3-d]pyrimidine derivatives
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The thiophne derivatives 4a-c were prepared according to the Gewald procedure. Their reactivity towards a variety of chemical reagents was studied to give thienopyridines and pyrimidines. Biological investigations were carried on the newly synthesized pro
- Wardakhan, Wagnat W.,Shams, Hoda Z.,Moustafa, Hosam E.
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p. 1815 - 1827
(2007/10/03)
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