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231.
232.
Javad Azizian Ramin Miri Mohammad Kazem Mohammadi Fatemeh Sheikholeslami Farahani Javad Hosseini Mohsen Nikpour 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1782-1787
New (pyrimido[4,5-e][1,3,4]thiadiazin-7-yl)hydrazines were synthesized via the cyclocondensation of alkyl-2-phenylhydrazinecarbodithioates as bidentate nucleophiles with 5-bromo-2,4-dichloro-6-methylpyrimidine as an electrophile and further replacement of chlorine atom on the seven number position of pyrimido[4,5-e][1,3,4]thiadiazin by hydrazine in boiling ethanol. 相似文献
233.
Ardeshir Khazaei Amin Rostami Fatemeh Mantashlo 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):2288-2296
The first catalytic application of p-toluenesulfonyl chloride (p-TsCl) for the efficient and selective trimethylsilylation of various types of hydroxyl groups with hexamethyldisilazane (HMDS) in dichloromethane and desilylation of these compounds in water is reported. The reactions were carried out at room temperature and were found to proceed in good to excellent yields. 相似文献
234.
Ali Ramazani Fatemeh Zeinali Nasrabadi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):1214-1219
Abstract The reaction between a thioacid and an α-haloketone in water affords thioester derivatives in high yields. The reaction proceeded smoothly and cleanly under mild conditions and no side reactions were observed. 相似文献
235.
Biochar is a stable and carbon‐rich solid which has a high density of carbonyl, hydroxyl and carboxylic acid functional groups on its surface. In this work, the surface of biochar nanoparticles (BNPs) was modified with 3‐choloropropyltrimtoxysilane and further 2‐(thiophen‐2‐yl)‐1H‐benzo[d]imidazole was anchored on its surface. Then, palladium nanoparticles were fabricated on the surface of the modified BNPs and further the catalytic application was studied as recyclable biocatalyst in carbon–carbon coupling reactions such as Suzuki–Miyaura and Heck–Mizoroki cross‐coupling reactions. The structure of the catalyst was characterized using scanning electron microscopy, transmission electron microscopy, energy‐dispersive X‐ray spectroscopy, thermogravimetric analysis, X‐ray diffraction and atomic absorption spectroscopy. The catalyst can be reused several times without a decrease in its catalytic efficiency. In addition to the several advantages reported, application of biochar as catalyst support for the first time is a major novelty of the present work. 相似文献
236.
Sahebeh Nikahd Reza Babadi Aghakhanpour S. Masoud Nabavizadeh Fatemeh Niroomand Hosseini S. Jafar Hoseini Arno Pfitzner Mozhgan Samandar Sangari 《应用有机金属化学》2019,33(11)
A new series of cycloplatinated (II) complexes with general formulas of [Pt (bhq)(N3)(P)] [bhq = deprotonated 7,8‐benzo[h]quinoline, P = triphenyl phosphine (PPh3) and methyldiphenyl phosphine], [Pt (bhq)(P^P)]N3 [P^P = 1,1‐bis (diphenylphosphino)methane (dppm) and 1,2‐bis (diphenylphosphino)ethane] and [Pt2(bhq)2(μ‐P^P)(N3)2] [P^P = dppm and 1,2‐bis (diphenylphosphino)acetylene] is reported in this investigation. A combination of azide (N3?) and phosphine (monodentate and bidentate) was used as ancillary ligands to study their influences on the chromophoric cyclometalated ligand. All complexes were characterized by nuclear magnetic resonance spectroscopy. To confirm the presence of the N3? ligand directly connected to the platinum center, complex [Pt (bhq)(N3)(PPh3)] was further characterized by single‐crystal X‐ray crystallography. The photophysical properties of the new products were studied by UV–Vis spectroscopy in CH2Cl2 and photoluminescence spectroscopy in solid state (298 or 77 K) and in solution (77 K). Using density functional theory calculations, it was proved that, in addition to intraligand charge‐transfer (ILCT) and metal‐to‐ligand charge‐transfer (MLCT) transitions, the L′LCT (L′ = N3, L = C^N) electronic transition has a remarkable contribution in low energy bands of the absorption spectra (for complexes [Pt (bhq)(N3)(P)] and [Pt2(bhq)2(μ‐P^P)(N3)2]). It is indicative of the determining role of the N3? ligand in electronic transitions of these complexes, specifically in the low energy region. In this regard, the photoluminescence studies indicated that the emissions in such complexes originate from a mixed 3ILCT/3MLCT (intramolecular) and also from aggregations (intermolecular). 相似文献
237.
Heck and oxidative boron Heck reactions employing Pd(II) supported amphiphilized polyethyleneimine‐functionalized MCM‐41 (MCM‐41@aPEI‐Pd) as an efficient and recyclable nanocatalyst
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Fatemeh Ashori Alireza Samzadeh‐Kermani Hosein Hamadi Mohammad Reza Ganjali Hamideh Aghahosseini Ali Ramazani Mehdi Khoobi Elham Gholibegloo 《应用有机金属化学》2018,32(3)
A novel nanocatalyst was developed based on covalent surface functionalization of MCM‐41 with polyethyleneimine (PEI) using [3‐(2,3‐Epoxypropoxy)propyl] trimethoxysilane (EPO) as a cross‐linker. Amine functional groups on the surface of MCM‐41 were then conjugated with iodododecane to render an amphiphilic property to the catalyst. Palladium (II) was finally immobilized onto the MCM‐41@PEI‐dodecane and the resulted MCM‐41@aPEI‐Pd nanocatalyst was characterized by FT‐IR, TEM, ICP‐AES and XPS. Our designed nanocatalyst with a distinguished core‐shell structure and Pd2+ ions as catalytic centers was explored as an efficient and recyclable catalyst for Heck and oxidative boron Heck coupling reactions. In Heck coupling reaction, the catalytic activity of MCM‐41@aPEI‐Pd in the presence of triethylamine as base led to very high yields and selectivity. Meanwhile, the MCM‐41@aPEI‐Pd as the first semi‐heterogeneous palladium catalyst was examined in the C‐4 regioselective arylation of coumarin via the direct C‐H activation and the moderate to excellent yields were obtained toward different functional groups. Leaching test indicated the high stability of palladium on the surface of MCM‐41@aPEI‐Pd as it could be recycled for several runs without significant loss of its catalytic activity. 相似文献
238.
Application of 2‐(benzyliminomethyl)‐6‐methoxy‐4‐(4‐methoxyphenyl‐azo)phenol in construction of ion‐selective PVC membrane electrode for determination of copper (II) in mineral water sample
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The potentiometric characteristics of a new Cu2+‐selective electrode based on 2‐(benzyliminomethyl)‐6‐methoxy‐4‐(4‐methoxyphenyl‐azo) phenol as an efficient ionophore has been evaluated. The effects of influential parameters on the potentiometric responses such as the amount of plasticizer, the amount of ionophore, pH of the sample solution, and the effect of coexisting ions on the electrode signal were subsequently investigated . The selectivity of the electrode was assessed by calculating the selectivity coefficients using the matched potential method. The optimum ratio of the amount of materials required for the preparation of the electrode was found to be 1.7: 32.1: 64.2: 2.0 corresponding to carboxylated PVC, dimethyl sebacate as solvent mediators, potassium tetrakis (p‐chlorophenyl) borate as the anion localizing agent, and ionophore, respectively. The electrode had a fast response (7s) as well as a satisfactory Nernstian slope (29.26±0.91 mV/decade) to Cu2+ over a wide concentration range of 2.0×10?6‐ 5.0×10?2 M with a low detection limit of 5.9×10?7 M. The developed sensor was successfully used for the potentiometric titration of Cu2+ ion with EDTA and subsequently, efficient determination of this metal ion in a mineral water sample was performed. 相似文献
239.
Polypyrrole/Fe3O4/CNT as a recyclable and highly efficient catalyst for one‐pot three‐component synthesis of pyran derivatives
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Polypyrrole (PPY)/Fe3O4/CNT has been synthesized and characterized by FT‐IR, TEM and SEM techniques and its catalytic activity has been evaluated in the synthesis of several series of pyran derivatives. Tetrahydrobenzo[b]pyranes, 4H‐pyran‐3‐carboxylates, 4H,5H‐pyrano[3,2‐c]chromenes and dihydropyrano[2,3‐c]pyrazoles have been successfully prepared from one‐pot three‐component condensation of aldehyde, malononitrile and active methylene‐containing compounds (dimedone /ethyl acetoacetate/4‐hydroxycoumarin/3‐methyl‐2‐pyrazoline‐5‐one) using PPY/Fe3O4/CNT as a new and reusable heterogeneous catalyst. The present method offer several advantages such as; high yields of products, short reaction times, easy work‐up procedure and easy separation of the catalyst from the reaction mixture due to its magnetic character. Furthermore, chemoselective synthesis of bis‐benzo[b]pyran from terephthalaldehyde can be achieved by this method. 相似文献
240.
Catalytic application of sulfonic acid‐functionalized titana‐coated magnetic nanoparticles for the preparation of 1,8‐dioxodecahydroacridines and 2,4,6‐triarylpyridines via anomeric‐based oxidation
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We have developed green, efficient and powerful protocols for the preparation of 2,4,6‐triarylpyridines and 1,8‐dioxodecahydroacridines in the presence of Fe3O4@TiO2@O2PO2(CH2)2NHSO3H as a sulfonic acid‐functionalized titana‐coated magnetic nanoparticle catalyst under mild and solvent‐free reaction conditions. These protocols furnished the desired products in short reaction times with good to high yields (20–40 min and 80–86% in the case of 2,4,6‐triarylpyridines; 15–90 min and 80–93% in the case of 1,8‐dioxodecahydroacridines). The final step of the mechanistic route in the synthesis of 2,4,6‐triarylpyridines proceeds via an anomeric‐based oxidation. Also, the nanomagnetic core–shell catalyst can be recycled and reused in both cases of the scrutinized one‐pot multicomponent reactions with high turnover number and turnover frequency. 相似文献