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1.
Maasoumeh Jafarpour Abdolreza Rezaeifard Reza Haddad Somayeh Gazkar 《Transition Metal Chemistry》2013,38(1):31-36
A zirconium(IV) complex of a bidentate Schiff base (ZrL2Cl2) has been synthesized by the reaction of (z)-N-benzylidene-2-hydroxypropane-1-amine (HL) and ZrCl4. Spectroscopic data and elemental analyses are consistent with a monomeric complex with a ligand:Zr ratio of 2:1. The catalytic activity of ZrL2Cl2 has been investigated for the efficient synthesis of a wide variety of quinoxaline derivatives under mild conditions. The employment of ethanol as an environmentally benign solvent in this high yield method, along with high turnover numbers and reusability of the catalyst providing ready scalability, makes it appropriate for practical applications. 相似文献
2.
Jamshid Rakhtshah Mohammad Ali Zolfigol Saeed Baghery 《Journal of Coordination Chemistry》2017,70(2):340-360
A nickel(II) Schiff base complex immobilized on multi-wall carbon nanotubes (MWCNTs) surface as a highly efficient heterogeneous catalyst was synthesized and characterized by IR, X-ray diffraction patterns, scanning electron microscopy, energy-dispersive X-ray spectroscopy, inductively coupled plasma, elemental analysis, and thermal gravimetric analysis. Then a facile and environmentally benign procedure was developed for synthesis of polyhydroquinoline derivatives via Hantzsch one-pot condensation reaction of aromatic aldehydes, 1,3-diones, ethyl acetoacetate, and ammonium acetate in the presence of above synthesized catalyst under solvent-free conditions. This protocol has the advantages of stability, easy availability, recyclability and eco-friendly nature of catalyst, simple experimental and work-up procedure, and also high to excellent yields. Considering the solvent-free condition and also temperature, time, and yield of the model reaction, the nanocatalyst reported here is among the best catalysts reported so far for synthesis of polyhydroquinolines. 相似文献
3.
V. V. Alekseyev A. G. Saminskaya S. I. Yakimovich 《Chemistry of Heterocyclic Compounds》2012,48(3):476-480
The reaction of carbohydrazide with 1,2-dicarbonyl compounds yields a series of ylidene derivatives, namely, mono- or bishydrazones, 5-hydroxy-, 5-alkoxy, or 5-methylene-4,5-dihydro-2H-[1,2,4]triazin-3-ones depending on the structure of the dicarbonyl compound and nature of the solvent. 相似文献
4.
N. S. Sadykhov Sh. S. Nasibov F. M. Muradova R. A. Gasymov 《Russian Chemical Bulletin》1998,47(2):310-312
Alkylation of acetylacetone, ethyl acetoacetate, and diethyl malonate with 1,2-dibromocyclohexane in the presence of K2CO3 in DMSO occurs only asC-alkylation accompanied by dehydrobromination, whereas a similar reaction of dimedone follows bothC- andO-alkylation pathways.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 317–319, February, 1998. 相似文献
5.
Olga A. Maloshitskaya Valery V. Alekseyev Kirill N. Zelenin Kalevi Pihlaja 《Tetrahedron》2006,62(40):9456-9466
The reaction products of 1,3-butanediamine and 2-methyl-2,4-pentanediamine with β-keto aldehydes were shown by 1H and 13C NMR spectroscopy to exist as tautomeric mixtures in solutions, comprising one cyclic and two open-chain forms due to the non-equivalence of the amino groups. The chain products exist as Z- and E-isomers. After equilibration, the products from 1,3-butanediamine contain relatively less of the cyclic form than those from 2-methyl-2,4-pentanediamine. The products of 2-methyl-2,4-pentanediamine with p-substituted aroylacetaldehydes, exhibit a linear correlation between log K of the ring-chain equilibria and Hammett's σ values of the aromatic ring substituents. α-Substitution of β-keto aldehydes notably increased the relative amounts of the chain E-isomers in their condensation products and also resulted in the formation of two diastereomers for each of the cyclic products. No ring-chain equilibria were observed in the products of 1,3-butanediamine and 2-methyl-2,4-pentanediamine with β-diketones, β-keto esters, or β-keto amides. 相似文献
6.
Herein, a new Cu(II) Schiff base complex was immobilized onto the magnetic graphene oxide surface through a stepwise procedure. The as-synthesized nanostructure (GO/Fe3O4/CuL) was characterized by various techniques including Fourier transform infrared (FT-IR), Raman spectroscopies, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), energy-dispersive X-ray (EDX) and inductively coupled plasma (ICP) spectroscopies, N2 adsorption–desorption analysis, vibrating sample magnetometry (VSM), and X-ray diffraction (XRD). The catalytic activity of the synthesized nanocatalyst was examined in 4-nitrophenol (4-NP), Congo red (CR), and methylene blue (MB) reduction using NaBH4 in an aqueous solution at room temperature. The reaction progress was monitored by UV–Vis spectroscopy. Also, the synthesized nanostructure was evaluated as an efficient catalyst for the synthesis of 2-amino-4H-benzopyrans via three-component reactions of 1-naphthol, malononitrile, and various aldehydes in ethanol/water at 50°C. The use of green solvents, the short reaction time, the high product yield, and easy separation from the reaction environment are the main benefits of this catalytic system. By covalent grafting of the complex on the graphene oxide surface, its catalytic performance significantly increased compared with graphene oxide; this is probably related to the chemical change of the graphene oxide surface. The results show the high chemical stability and the improved reusability of the synthesized nanocatalyst (six times) without significant loss in the catalytic activity of GO/Fe3O4/CuL nanocomposite. 相似文献
7.
The novel functionalized Fe3O4@SiO2@APTMS@Glu-His@Cu complex was prepared from modification of iron oxide nanomagnet particles with (3-aminopropyl) trimethoxysilane (APTMS) and glutaraldehyde–histidine Schiff base followed by complexation with Cu(I) salt. Characterization of this complex was carried out by means of FTIR, XRD, SEM, TEM and VSM techniques. The complex was found to successfully catalyze the oxidative homocoupling of phenylacetylene, 4-tert-butylphenylacetylene, 1-ethynyl-4-fluorobenzene and pent-1-yn-3-ol with 67–100 % conversions and 95–100 % selectivities. Magnetic recovery and recycling of the catalyst without significant decrease in activity is described in this presentation. 相似文献
8.
Schiff base complex of palladium immobilized on magnetic nanoparticles: an efficient and recyclable nanocatalyst for CC coupling reactions
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A Schiff base complex of palladium anchored on Fe3O4 magnetic nanoparticles as an efficient and magnetically reusable nanocatalyst is reported for C? C bond formation through Heck and Suzuki reactions. The catalyst was easily recovered and reused several times without significant loss of its catalytic efficiency or palladium leaching. The magnetic nanocatalyst was characterized using Fourier transform infrared and inductively coupled plasma atomic emission spectroscopies, thermogravimetric analysis, vibrating sample magnetometry, and transmission and scanning electron microscopies. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
9.
Bagher Eftekhari-Sis Masoud Akbari Mojtaba Amini Fatemeh Ashouri Mojtaba Bagherzadeh 《Journal of Coordination Chemistry》2017,70(2):328-339
Oxoperoxo tungsten(VI) complex immobilized on Schiff base-modified Fe3O4 super paramagnetic nanoparticles were synthesized and appropriately characterized using FT-IR, XRD, SEM, TEM, EDX, BET, and VSM analysis. The synthesized nanoparticles efficiently catalyzed oxidation of benzylic alcohols with H2O2 as oxidant in high yields, with high to excellent selectivity. The catalyst can be recovered using an external magnetic field and recycled for subsequent oxidation reactions without any appreciable loss of efficiency. The simple preparation, high activity, excellent selectivity, and simple recoverability of the catalyst are advantageous. 相似文献
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11.
Xiang-Shan Wang Mei-Mei Zhang Da-Qing Shi Shu-Jiang Tu Xian-Yong Wei 《Tetrahedron letters》2005,46(42):7169-7173
A clean and simple synthesis of benzo[c]acridine, benzo[a]acridine, pyrido[2,3-c]acridine and benzo[f]quinoline derivatives was accomplished in good to excellent yields via the reaction of Schiff base with 1,3-dicarbonyl compounds in aqueous medium catalyzed by TEBA. The structures were characterized by 1H NMR, IR and elemental analysis, and confirmed by X-ray diffraction study. 相似文献
12.
D. G. Mazhukin A. Ya. Tikhonov L. B. Volodarskii E. P. Konovalova 《Chemistry of Heterocyclic Compounds》1993,29(4):437-445
The condensation of 1,2-bishydroxylamines with 1,2-dicarbonyl compounds led to the isolation of derivatives of 2,3-dihydropyrazine-1,4-dioxide. The 2,3-bis(bromomethyl)-4a,5,6,7,8,8a-hexahydroquinoxaline reacts readily with O- and N-nucleophiles; condensed pyrazines are formed by interaction with o-phenylenediamine, phenylhydrazine, and tert-butylamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 514–522, April, 1993. 相似文献
13.
A copper(II) Schiff base complex has been immobilized onto SBA-15 silica through a stepwise procedure and tested as an oxidation catalyst. BET surface area, total pore volume and average pore width of the SBA-15 all decrease after stepwise modification of SBA-15, while the structure of the support remains intact. The molar ratio of Cu2+/Schiff base is ca. 1/2 in the synthesized material. Catalytic tests showed that the supported copper complex catalyzes the oxidation of benzyl alcohol with 30 % conversion and 89 % selectivity to benzaldehyde when water is used as the solvent. 相似文献
14.
Ghahremani Mahboubeh Davarpanah Jamal Rezaee Parizad Davoodi Ghazal 《Research on Chemical Intermediates》2020,46(5):2683-2704
Research on Chemical Intermediates - In this study, the nanoparticles of amorphous silica were easily extracted from low-cost rice husk ash. They were functionalized with 3-(chloropropyl)... 相似文献
15.
Copper Schiff base complex immobilized on silica‐coated Fe3O4 nanoparticles: a recoverable and efficient catalyst for synthesis of polysubstituted pyrroles
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Seyedeh Aghigh Hamrahian Jamshid Rakhtshah Seyedeh Mohadeseh Mousavi Davijani Sadegh Salehzadeh 《应用有机金属化学》2018,32(10)
In this work, a copper Schiff base complex immobilized on silica‐coated Fe3O4 nanoparticles is synthesized, and studied as a highly efficient, recyclable, green and heterogeneous catalyst for the preparation of polysubstituted pyrroles under solvent‐free and mild conditions. This new catalyst was characterized by different techniques, such as Fourier transform infrared (FT‐IR), X‐ray powder diffraction (XRD), field‐emission scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDX), inductively coupled plasma (ICP) and vibrating sample magnetometry (VSM). The simple and environmentally one‐pot multicomponent condensation of nitromethane, an aryl aldehyde, a 1,3‐dicarbonyl compound and an amine in the presence of above catalyst affords the title compounds at room temperature. At the end, we compared the results for the synthesis of polysubstituted pyrroles in the presence of our nanocatalyst with previously reported catalysts in the literature. 相似文献
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17.
The steric and electronic influences of substituents attached to the 1,2-dicarbonyl system on the success of the reaction of 1,2- diketones with dimethyl 3-ketoglutarate have been examined. It is clear from the reaction of with benzil, thienil, furil, and phenanthrenequinone , respectively, coupled with 13C NMR spectroscopy of the reaction intermediates, that steric effects play a major role in the overall success of the reaction to provide . This is analogous to the situation observed earlier with 1,2-diketones, R-CO-CO-R, where R represented an aliptiatic or alicyclic group. 相似文献
18.
Sh. T. Akhmedov N. S. Sadykhov V. M. Ismailov M. A. Akhundova M. M. Mamedov S. I. Kozhushkov N. S. Zefirov 《Chemistry of Heterocyclic Compounds》1987,23(6):651-655
The reaction of 2-(2-halo-3-propenyl)-1,3-dicarbonyl compounds, which are formed in the alkylation of -dicarbonyl compounds with 1,2,3-trihalopropanes in the presence of potassium carbonate in DMSO, with hydrazine and hydroxylamine derivatives was studied. The synthesis of new pyrazole and isoxazole derivatives on the basis of this reaction is described. Some chemical transformations of the 1,2-azoles obtained were investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 787–791, June, 1987. 相似文献
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20.
Yang TL Qin WW 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,67(2):568-571
A new Schiff base ligand with tripodal structure, N,N',N'-tri-(3-indolemethanal)-triaminotriethylamine (L), and its complex with terbium was synthesized. The complex was characterized by element analysis, IR spectra, mass spectra, thermal analysis and molar conductivity. The terbium ion was found to coordinate to the Schiff base nitrogen atoms and the bridgehead nitrogen atom. The fluorescence properties of the complex in aqueous solutions were studied. Under the excitation of UV light, the complex exhibits characteristic fluorescence of terbium ion. H(+) concentration could strongly enhance the luminescence of terbium complex with L in aqueous solutions. This phenomenon will make the new complex favorable to be used in the fluorescence switches and sensors. The mechanism of the fluorescence enhancement by protonation of the indole nitrogen atoms is due to the suppressed photoinduced electron transfer (PIET) fluorescence quenching when adding acid. 相似文献