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1.
A new, one‐pot condensation of aldehydes, enolizable ketones and esters, AcCl, and MeCN, in the presence of Fe3O4 nanoparticles (nano‐Fe3O4) as an efficient catalyst, for the preparation of β‐acetamido carbonyl compounds at room temperature is described. 相似文献
2.
《应用有机金属化学》2017,31(10)
A facile, green and efficient method for the immobilization of MoO2–Salen onto graphene hybridized with glucose‐coated magnetic Fe3O4 nanoparticles is proposed to fabricate a magnetic organic–inorganic hybrid heterogeneous RGO/Fe3O4@C‐Salen‐MoO2 catalyst for the epoxidation of cyclooctene and geraniol using tert ‐butyl hydroperoxide or H2O2 as oxidant. Carbon‐coated Fe3O4 can improve the stability and add functional ─OH groups on the surface of Fe3O4. The fabricated composite exhibited good performance due to good dispersion of MoO2–Salen active sites. The catalyst can be easily separated from the reaction system using a permanent magnet and used three times without significantly losing its catalytic activity and selectivity. 相似文献
3.
《应用有机金属化学》2017,31(7)
Tribenzylammonium tribromide supported onto magnetic nanoparticles (Br3‐TBA‐Fe3O4) as a bromine source was successfully synthesized and characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, X‐ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy and vibrating sample magnetometry. The synthesized catalyst is shown to be a versatile and highly efficient heterogeneous catalyst for the Knoevenagel condensation and synthesis of 2,3‐dihydroquinazolin‐4(1H )‐one and polyhydroquinoline derivatives. To the best of the authors' knowledge, this is the first report of the use of a bromine source immobilized on Fe3O4 nanoparticles as a magnetically separable catalyst for these reactions. The nanosolid catalyst can be magnetically recovered and reused readily several times without significant loss in catalytic efficiency. 相似文献
4.
A new nano‐Fe3O4‐supported organocatalyst based on 3,4‐dihydroxypyridine: an efficient heterogeneous nanocatalyst for one‐pot synthesis of pyrazolo[3,4‐b]pyridines and pyrano[2,3‐d]pyrimidines
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A simple and practical strategy for the synthesis of a novel nano‐Fe3O4‐supported organocatalyst system based on 3,4‐dihydroxypyridine (Fe3O4/Py) has been developed. The prepared catalyst was characterized using Fourier transform infrared spectroscopy, transmission and scanning electron microscopies, X‐ray diffraction, vibrating sample magnetometry and energy‐dispersive X‐ray analysis. Accordingly, the Fe3O4/Py nanoparticles show a superparamagnetic property with a saturation magnetization of 61 emu g?1, indicating potential application in magnetic separation technology. Our experimental results reveal that the pyridine‐functionalized Fe3O4 nanoparticles are an efficient base catalyst for the domino condensation of various aromatic aldehydes, Meldrum's acid and 5‐methylpyrazol‐3‐amine under very mild reaction condition and in the presence of ethanol solvent. Moreover, the synthesized catalyst was used for one‐pot, three‐component condensation of aromatic aldehydes with barbituric acid and malononitrile to produce 7‐amino‐2,4‐dioxo‐5‐phenyl‐2,3,4,5‐tetrahydro‐1H‐pyrano[2,3‐d]pyrimidine‐6‐carbonitriles. All reactions are completed in short times and all products are obtained in good to excellent yields. Also, notably, the catalyst was reused five times without significant degradation in catalytic activity and performance. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
5.
《应用有机金属化学》2017,31(10)
A new heterogeneous catalyst containing a copper(II) Schiff base complex covalently immobilized on the surface of silica‐coated Fe3O4 nanoparticles (Fe3O4@SiO2‐Schiff base‐Cu(II)) was synthesized. Characterization of this catalyst was performed using various techniques. The catalytic potential of the catalyst was investigated for the oxidation of various alkenes (styrene, α‐methylstyrene, cyclooctene, cyclohexene and norbornene) and alcohols (benzyl alcohol, 3‐methoxybenzyl alcohol, 3‐chlorobenzyl alcohol, benzhydrol and n ‐butanol) using tert ‐butyl hydroperoxide as oxidant. The catalytic investigations revealed that Fe3O4@SiO2‐Schiff base‐Cu(II) was especially efficient for the oxidation of norbornene and benzyl alcohol. The results showed that norbornene epoxide and benzoic acid were obtained with 100 and 87% selectivity, respectively. Moreover, simple magnetic recovery from the reaction mixture and reuse for several times with no significant loss in catalytic activity were other advantages of this catalyst 相似文献
6.
《Electroanalysis》2017,29(12):2896-2905
In this study, immobilized hollow nanospheres of Fe3O4 with Palladium, Platinum and Gold nanoparticles (Fe3O4HNS‐PdPtAuNPs) was synthesized by hydrothermal and chemical reduction methods and characterized by various techniques such as field emission scanning electron microscopy, energy dispersive analysis of X‐rays and elemental mapping images. The electrocatalytic activity of the modified glassy carbon electrode (GCE) with Fe3O4HNS‐PdPtAuNPs (GCE/Fe3O4HNS‐PdPtAuNPs) toward methanol electrooxidation was investigated by cyclic voltammetry and chronoamperometry in 1 M NaOH solution. According to the results, Fe3O4HNS‐PdPtAuNPs catalyst demonstrated the highest efficiency for methanol electrooxidation in comparison with Fe3O4HNS‐PdNPs, Fe3O4HNS‐PtNPs, Fe3O4HNS‐PdAuNPs, Fe3O4HNS‐PtAuNPs and Fe3O4HNS‐PdPtNPs. The value of electron transfer coefficient (α ) and the ratio of current densities (If /Ib ) for methanol oxidation on the Fe3O4HNS‐PdPtAuNPs/GC catalyst were calculated 0.61 and 5.13, respectively. The reaction order was discovered to be 0.98 for CH3OH. A direct methanol fuel cell was developed with the suggested catalyst under several conditions. 相似文献
7.
《应用有机金属化学》2017,31(5)
A magnetic inorganic–organic nanohybrid material (HPA/TPI‐Fe3O4 NPs) was produced as an efficient, highly recyclable and eco‐friendly catalyst for the one‐pot multi‐component synthesis of malonamide and 2,3,4,5‐tetrahydrobenzo[b ][1,4]oxazepine derivatives with high yields in short reaction times (25–35 min) in aqueous media at room temperature. The nanohybrid catalyst was prepared by the chemical anchoring of H6P2W18O62 onto the surface of modified Fe3O4 nanoparticles (NPs) with N ‐[3‐(triethoxysilyl)propyl]isonicotinamide (TPI) linker. The magnetic recoverable catalyst was easily recycled at least ten times without any loss of catalytic activity. 相似文献
8.
A new Fe3O4 magnetic nanoparticles supported manganese salen complex was successfully prepared by attaching manganese acetates to a novel N,N′‐bis(salicylidine)ethylenediamine ligand functionalized Fe3O4. The as‐prepared catalyst was characterized by TGA, XRD, FTIR, VSM, and TEM. It was found to be an efficient catalyst for the synthesis of benzopyranopyrimidines in aqueous medium. High catalytic activity and ease of recovery from the reaction mixture using external magnet, and several reuse times without significant losses in performance are additional eco‐friendly attributes of this catalytic system. 相似文献
9.
The present study demonstrates the development of a supramolecular porous ensemble consisting of hetero‐oligophenylene derivative 6 and Au‐Fe3O4 nanodots. Supramolecular assemblies of AIE‐active hetero‐oligophenylene derivative 6 served as reactors for the generation of Au‐Fe3O4 nanodots. The as prepared supramolecular ensemble functioned as an efficient recyclable photocatalytic system for C(sp2)?H bond activation of anilines for the construction of quinoline carboxylates. Interestingly, the “dip catalyst” prepared by depositing PTh‐co‐PANI‐6: Au‐Fe3O4 nanodots on a filter paper served as a recyclable strip (up to 10 cycles) for C?C/C?N bond formation reaction. 相似文献
10.
Butane‐1‐sulfonic acid immobilized on magnetic Fe3O4@SiO2 nanoparticles: A novel and heterogeneous catalyst for the one‐pot synthesis of barbituric acid and pyrano[2,3‐d] pyrimidine derivatives in aqueous media
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Butane‐1‐sulfonic acid immobilized on magnetic Fe3O4@SiO2 nanoparticles (Fe3O4@SiO2‐Sultone) was easily prepared via direct ring opening of 1,4‐butanesultone with nanomagnetic Fe3O4@SiO2. The prepared reagent was characterized and used for the efficient promotion of the synthesis of barbituric acid and pyrano[2,3‐d] pyrimidine derivatives. All reactions were performed under mild and completely heterogeneous reaction conditions affording products in good to high yields. The catalyst is easily isolated from the reaction mixture by magnetic decantation and can be reused at least eight times without significant loss in activity. 相似文献
11.
《应用有机金属化学》2017,31(12)
The Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) were modified with 1,10‐phenanthroline‐5,6‐diol and the relevant Co complex (Fe3O4@Phendiol@Co) synthesized as a nano‐magnetic heterogeneous catalyst to be used for the N ‐formylation of various amines at room temperature under solvent‐free conditions. Also, in order to find the better concept of the catalyst role, the N ‐formylation reaction was carried out by the use of ultrasound irradiation in the absence of the Co nano‐catalyst and the results were compared. The catalyst characterized by different methods such as the elemental analysis (CHN), ICP, FT‐IR, XRD, EDX, SEM, TEM, TG‐DTA, VSM and XPS. In addition, the antioxidant and the antibacterial activities of the Fe3O4@Phendiol@Co nano‐catalyst and its Phendiol ligand were in vitro screened by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) free radical scavenging and disc diffusion methods. Results showed that they possess strong antioxidant activity (IC50; 0.182 ± 0.006 mg/ml) and good antibacterial potential in comparison to standards. 相似文献
12.
Chandan Kumar Pal Swagatika Sahu Ranjan Kumar Sahu Rajesh Kumar Singh Ashis Kumar Jena 《应用有机金属化学》2019,33(8)
A convenient method for the synthesis of magnetically recyclable palladium nanoparticles (Fe3O4‐Pd) is described. The catalytic application of the Fe3O4‐Pd nanoparticles was explored for the first time in oxidative coupling between amides and olefins. p‐Toluenesulfonic acid plays a significant role in the oxidative amidation reaction. The reaction proceeds at room temperature, resulting in (Z)‐enamides under ambient air in the absence of co‐catalyst and ligand. The superparamagnetic nature of Fe3O4‐Pd facilitates easy, quantitative recovery of the catalyst from a reaction mixture, and it can be reused for up to three consecutive cycles with a slight decrease in catalytic activity. 相似文献
13.
Kazem Karami Nasrin Jamshidian Mohammad Mehdi Nikazma Pablo Hervés Amir Rezaei Shahreza Ali Karami 《应用有机金属化学》2018,32(1)
We report a simple process for the synthesis of Fe3O4@SiO2/APTMS (APTMS = 3‐aminopropyltrimethoxysilane) core–shell nanocatalyst support. The new nanocatalyst was prepared by stabilization of Pd(cdha)2 (cdha = bis(2‐chloro‐3,4‐dihydroxyacetophenone)) on the surface of the Fe3O4@SiO2/APTMS support. The structure and composition of this catalyst were characterized using various techniques. An efficient method was developed for the synthesis of a wide variety of biaryl compounds via fluoride‐free Hiyama cross‐coupling reactions of aryl halides with arylsiloxane, with Fe3O4@SiO2/APTMS/Pd(cdha)2 as the catalyst under reaction conditions. This methodology can be performed at 100°C through a simple one‐pot operation using in situ generated palladium nanoparticles. High catalytic activity, quick separation of catalyst from products using an external magnetic field and use of water as green solvent are attributes of this protocol. 相似文献
14.
Xuerong Peng Xuchun Chen Tao Liu Changfang Lu Mengmeng Sun Fang Ding Yanying Wang Ping Zou Xianxiang Wang Qingbiao Zhao Hanbing Rao 《化学:亚洲杂志》2019,14(15):2744-2750
In order to accelerate the reaction rate of water splitting, it is of immense importance to develop low‐cost, stable and efficient catalysts. In this study, the facile synthesis of a novel rose‐like nanocomposite catalyst (Ni2P/Fe2P/Fe3O4) is reported. The synthesis process includes a solvothermal step and a phosphatization step to combine iron oxides and iron‐nickel phosphides. Ni2P/Fe2P/Fe3O4 performs well in catalyzing oxygen evolution reaction, with a very low overpotential of 365 mV to reach 10 mA cm?2 current density. The Tafel slope is as low as 59 mV dec?1. Ni2P/Fe2P/Fe3O4 has a large double‐layer capacitance that contributes to a high electrochemically active area. Moreover, this catalyst is very stable for long‐term use. Therefore, the Ni2P/Fe2P/Fe3O4 catalyst has a high potential for use in oxygen evolution reactions. 相似文献
15.
Zinc oxide‐decorated superparamagnetic silica attached to graphene oxide (Fe3O4/SiO2/PTS‐GO‐ZnO), as a novel nanocomposite, was designed, and its core‐shell structure was appropriately characterized by different spectroscopy or microscopy methods and thermal techniques as well as measuring of its porosity and magnetic properties. The catalytic activity of Fe3O4/SiO2/PTS‐GO‐ZnO, as a reusable heterogeneous catalyst, was investigated for efficient one‐pot multi‐component synthesis of medicinally important functionalized 2‐amino‐6‐(2‐oxo‐2H‐chromen‐3‐yl)‐4‐arylnicotinonitrile derivatives. The significant features of the present procedure are mild reaction conditions, low loading of the catalyst, high to quantitative yields of the desired products, avoiding the use of toxic heavy metals or solvents, simple isolation and purification of the products, and stability as well as reusability of the catalyst after at least six consecutive runs. 相似文献
16.
Preparation of novel palladium nanoparticles supported on magnetic iron oxide and their catalytic application in the synthesis of 2‐imino‐3‐phenyl‐2,3‐dihydrobenzo[d]oxazol‐5‐ols
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Novel Pd nanoparticles were prepared in five successive stages: 1) preparation of the Fe3O4 magnetic nanoparticles (Fe3O4 MNPs), 2) coating of Fe3O4 MNPs with SiO2 (Fe3O4@SiO2), 3) functionalization of Fe3O4@SiO2 with 3‐chloropropyltrimethoxy‐ silane (CPTMS) ligand (Fe3O4@SiO2@CPTMS), 4) further functionalization with 3,5‐diamino‐1,2,4‐triazole (DAT) ligand (Fe3O4@SiO2@CPTMS @DAT), and 5) the complexation of Fe3O4@SiO2@CPTMS@DAT with PdCl2 (Fe3O4@SiO2@CPTMS@ DAT@Pd). Then, the obtained Pd nano‐catalyst characterized by different methods such as the elemental analysis (CHN), FT‐IR, XRD, EDX, SEM, TEM, TG‐DTA and VSM. Finally, the Pd catalyst was applied for the synthesis of various 2‐imino‐3‐phenyl‐2,3‐dihydrobenzo[d]oxazol‐5‐ols. 相似文献
17.
We report the synthesis of magnetically separable Fe3O4@Silica‐Threonine‐Pd0 magnetic nanoparticles with a core–shell structure. After synthesis of Fe3O4@Silica, threonine as an efficient stabilizer/ligand was bonded to the surface of Fe3O4@Silica. Then, palladium nanoparticles were generated on the threonine‐modified catalyst. The threonine stabilizer helps to generate palladium nanoparticles of small size (less than 4 nm) with high dispersity and uniformity. Magnetically separable Fe3O4@Silica‐Threonine‐Pd0 nanocatalyst was fully characterized using various techniques. This nanocatalyst efficiently catalysed the Heck cross‐coupling reaction of a variety of substrates in water medium as a green, safe and inexpensive solvent at 80°C. The Fe3O4@Silica‐Threonine‐Pd0 catalyst was used for at least eight successful consecutive runs with palladium leaching of only 0.05%. 相似文献
18.
An efficient procedure for the synthesis of new chromenes by the multicomponent reaction of aldehydes, 4‐hydroxycoumarin and 2‐hydroxynaphthalene‐1,4‐dione in the presence of an ionic liquid supported on Fe3O4 nanoparticles is described. The ionic liquid supported on Fe3O4 nanoparticles as a magnetic catalyst gives products in high yields. Significant features of this method are: short reaction times, excellent yields, green method and use of an effective catalyst that can be recovered and reused many times without loss of its catalytic activity. 相似文献
19.
In this research, a one‐pot, efficient, and high yielding procedure for the synthesis of imidazole derivatives is investigated. The procedure was carried out via multicomponent reaction of isothiocyanate, alkyl bromides, N‐methylimidazole, and triphenylphosphine in the presence of magnetic iron oxide nanoparticles (Fe3O4‐MNPs) as reusable catalyst under solvent‐free conditions at 50°C. Also, Fe3O4‐MNPs were produced using green synthetic method by reduction of ferric chloride solution with Clover Leaf water extract. The nanoparticles generated using this procedure can potentially be important in different purposes such as organic synthesis. Easy, simple, rapid, and clean procedures for the synthesis of imidazole derivatives are the advantages of this study. 相似文献
20.
An advanced novel magnetic ionic liquid based on imidazolium tagged with ferrocene, a supported ionic liquid, is introduced as a recyclable heterogeneous catalyst. Catalytic activity of the novel nanocatalyst was investigated in one‐pot three‐component reactions of various aldehydes, malononitrile and 2‐naphthol for the facile synthesis of 2‐amino‐3‐cyano‐4H‐pyran derivatives under solvent‐free conditions without additional co‐catalyst or additive in air. For this purpose, we firstly synthesized and investigated 1‐(4‐ferrocenylbutyl)‐3‐methylimidazolium acetate, [FcBuMeIm][OAc], as a novel basic ferrocene‐tagged ionic liquid. This ferrocene‐tagged ionic liquid was then linked to silica‐coated nano‐Fe3O4 to afford a novel heterogeneous magnetic nanocatalyst, namely [Fe3O4@SiO2@Im‐Fc][OAc]. The synthesized novel catalyst was characterized using 1H NMR, 13C NMR, Fourier transform infrared and energy‐dispersive X‐ray spectroscopies, X‐ray diffraction, and transmission and field emission scanning electron microscopies. Combination of some unique characteristics of ferrocene and the supported ionic liquid developed the catalytic activity in a simple, efficient, green and eco‐friendly protocol. The catalyst could be reused several times without loss of activity. 相似文献