- Immobilization of Gd(III) complex on Fe3O4: A novel and recyclable catalyst for synthesis of tetrazole and S–S coupling
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In the present work, a novel catalysts prepared by the anchoring of Gd(III) complex with OH groups on the surface of Fe3O4 in which characterized by FT-IR, TGA, XRD, EDX, VSM, and ICP-OES techniques and tested in the synthesis of tetrazoles and S–S coupling. This designed methods indicated several advantages including easily recovered from the reaction mixture by magnetic field, several consecutive cycles without noticeable change in its catalytic activity, the use of green solvent, the use of aspartic acid as green ligand, chemical and physical stability of obtained catalyst, short time reaction and good to excellent isolated yields of all product. Also, up to date, Gd(III) complex don't used for the synthesis of tetrazoles and S–S coupling.
- Nemati, Mohammad,Tamoradi, Taiebeh,Veisi, Hojat
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- Highly ordered mesoporous La(III)-substituted 5-oxopyrrolidine-2-carboxylic acid (Glp) immobilized on SBA-15 as a very efficient nanocatalyst for green aerobic oxidative coupling of thiols to disulfides
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Selective aerobic oxidative coupling of thiols that are catalyzed by La(III)-substituted 5-oxopyrrolidine-2-carboxylic acid (Glp) immobilized on SBA-15 (SBA-15@Glp–La; SBA = Santa Barbara amorphous) was studied. Using SBA-15@Glp–La, the complete conversio
- Molaei, Somayeh,Ghadermazi, Mohammad
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- Synthesis and characterization of indium and thallium immobilized on isonicotinamide-functionalized mesoporous MCM-41: Two novel and highly active heterogeneous catalysts for selective oxidation of sulfides and thiols to their corresponding sulfoxides and disulfides
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Two highly ordered isonicotinamide (INA)-functionalized mesoporous MCM-41 materials supporting indium and thallium (MCM-41-INA-In and MCM-41-INA-Tl) have been developed using a covalent grafting method. A surface functionalization method has been applied to prepare Cl-modified mesoporous MCM-41 material. Condensation of this Cl-functionalized MCM-41 with INA leads to the formation of MCM-41-INA. The reaction of MCM-41-INA with In(NO3)3 or Tl(NO3)3 leads to the formation of MCM-41-INA-In and MCM-41-INA-Tl catalysts. The resulting materials were characterized using various techniques. These MCM-41-INA-In and MCM-41-INA-Tl catalysts show excellent catalytic performance in the selective oxidation of sulfides and thiols to their corresponding sulfoxides and disulfides. Finally, it is found that the anchored indium and thallium do not leach out from the surface of the mesoporous catalysts during reaction and the catalysts can be reused for seven repeat reaction runs without considerable loss of catalytic performance.
- Molaei, Somayeh,Ghadermazi, Mohammad
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- N-unsubstituted sulfenamides by electrophilic amination of mercapto compounds
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Potential mercapto compounds derived from electron deficient heterocycles as 2- and 4-thiouracils, pyridines and pyridine-1-oxide are animated by the oxaziridine 1 to new sulfenamides (6, 9, 11 and 15 or the isothiazolo-pyridine 14) which add to phenylisocyanates forming sulfenylureas (7, 10, 12 and 16). Several other mercapto compounds gave disulfides. Attempts of oxidation of the sulfenamides and the sulfenylureas were unsuccessful. The methylmercapto compound 19 after amination was hydrolyzed to the sulfoxide 20. Johann Ambrosius Barth 1997.
- Andreae, Siegfried
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- Multifunctional thioxanthone derivatives with acetylcholinesterase, monoamine oxidases and β-amyloid aggregation inhibitory activities as potential agents against Alzheimer's disease
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A series of 1-hydroxyl-3-aminoalkoxy-thioxanthone derivatives were designed, synthesized and evaluated as potential multifunctional agents against Alzheimer's disease (AD). The results indicated that most of these compounds exhibited good AChE and MAOs inhibitory activities, significant inhibition of self- and Cu2+-induced Aβ1-42aggregation, and moderate to good antioxidant activities. Specifically, compound 9e displayed high inhibitory potency toward AChE (IC50= 0.59 ± 0.02 μM), MAO-A and MAO-B (IC50= 1.01 ± 0.02 μM and 0.90 ± 0.01 μM respectively), excellent efficiency to block both self- and Cu2+-induced Aβ1-42aggregation (74.8 ± 1.2% and 87.7 ± 1.9% at 25 μM, respectively), good metal-chelating property and a low toxicity in SH-SY5Y cells. Furthermore, kinetic and molecular modeling studies revealed that compound 9e binds simultaneously to the catalytic active site and peripheral anionic site of AChE, and could penetrate the BBB. Collectively, these results suggested that 9e might be a potential multifunctional agent for further development in the treatment of AD.
- Luo, Li,Li, Yan,Qiang, Xiaoming,Cao, Zhongcheng,Xu, Rui,Yang, Xia,Xiao, Ganyuan,Song, Qing,Tan, Zhenghuai,Deng, Yong
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- Fe3O4@MCM-41@Zn-Arg: as a novel, magnetically recoverable and ecofriendly nanocatalyst for the synthesis of disulfides, sulfoxides and 2,3-dihydroquinazolin?4(1H)?ones
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The direct supporting of Zn-arginine complex on magnetic core-shell nanostructures (Fe3O4@MCM-41@Zn-Arg) was reported as a novel, heterogeneous and excellent nanocatalyst, which applied for the oxidation reaction of sulfides to sulfoxides, oxidative coupling of thiols to their corresponding disulfides and the synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives under mild conditions. The structure of the catalyst was studied by X-Ray diffraction, Fourier transform-infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, atomic absorption spectroscopy, and vibrating sample magnetometry techniques. The simple experimental procedure, very good catalytic activity, low cost, and excellent recycling are the noteworthy features of the currently employed heterogeneous catalytic system.
- Nikoorazm, Mohsen,Erfani, Zahra
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- Neodymium immobilized on Fe3O4: A new and recoverable catalyst for oxidation reactions and synthesis of 5‐substituted 1H-tetrazoles in green condition
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Magnetic nanoparticle functionalized with neodymium complex as catalyst and characterized by SEM, XRD, FT-IR, TGA, EDX and ICP techniques. Then, catalytic activity of prepared catalyst was examined in the synthesis of tetrezoles and oxidation reactions in
- Ghadermazi, Mohammad,Taherabadi, Samira,Tamoradi, Taiebeh
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- Reactions of benzo and dibenzo derivatives of five-membered aromatic heterocycles with ozone in the liquid phase
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The ozonation reactions of benzo and dibenzo derivatives of pyrrole, furan, and thiophene in acetic acid solution have been studied. Peroxide compounds have been detected as the products. The mechanism of ozone interaction with these hetarenes has been proposed. The kinetics of ozonolytic reactions of benzologues of five-membered aromatic heterocycles (hetarenes) have been investigated. The reaction of ozone with the hetarenes obeys the bimolecular rate law and has the first order in each reactant. The effective rate constants and experimental stoichiometric coefficients for ozone have been found.
- Andreev
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- Metal-free oxidative coupling of thiols to disulfides using guanidinium nitrate or nitro urea in the presence of silica sulfuric acid
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Efficient combination of nitro urea or guanidinium nitrate and silica sulfuric acid (SiO2OSO3H) as a new oxidizing system is able to oxidize a variety of aliphatic or aromatic thiols to the corresponding disulfides. The process reported here is operationally simple, environmentally benign and reactions have been mildly and heterogeneously performed in dichloromethane at room temperature. Indian Academy of Sciences.
- Ghorbani-Choghamarani, Arash,Nikoorazm, Mohsen,Goudarziafshar, Hamid,Shokr, Alireza,Almasi, Hosein
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- Catalytic oxidation of thiol compounds by novel fuel cell-inspired co-porphyrin and co-imidazole catalysts
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The catalytic performance of pyrolyzed carbon-supported cobalt-nitrogen donor (CoN4) catalysts for the oxidation of thiol compounds by dioxygen in aqueous solution was studied. This paper continues our previous line of research, which was inspired by the electrocatalytic reduction of oxygen on pyrolyzed carbon-supported cobalt-porphyrins and related tetra-coordinated nitrogen donor-transition metal complexes (MeN4, where Me stands for a transition metal atom). Both pyrolyzed carbon-supported Co-imidazole and Co-porphyrin exhibited fast catalytic oxidation of the different thiols. The rate of oxidation of different thiols on the pyrolyzed CoN4 catalysts was compared to the homogeneous rate of oxidation using 5,10,15,20-tetrakis(4- sulfonatophenyl)porphyrin Co(II) tetrasodium salt as catalyst. Based on the cobalt content, the heterogeneous catalysts always outperformed the homogeneous one, and at times even exhibited 4,100-fold better catalysis. The dependence of the catalytic rate of oxidation on the preparation temperature was investigated, showing an optimal catalysis at ~650 °C for the cobalt-imidazole catalyst. The decrease in catalytic performance after heat treatment at elevated temperature was attributed to the formation of cobalt metal acting as a generator of carbon nanotubes.
- Goifman, Anatoly,Gun, Jenny,Gelman, Faina,Ekeltchik, Irina,Worch, Eckhard,Lev, Ovadia
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- Reactions of 3,5-di-tert-butyl-1,2-benzoquinone with mercapto carboxylic acids
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Heating of an equimolar mixture of 3,5-di-tert-butyl-1,2-benzoquinone with thiosalicylic acid led to 2-[(4,6-di-tert-butyl-2,3-dihydroxyphenyl)thio]benzoic acid. In the case of β-mercaptopropionic acid, 2-[(4,6-di-tert-butyl-2,3-dihydroxyphenyl)thio]propi
- Ukhin, L. Yu.,Suponitsky, K. Yu.,Shepelenko,Belousova,Alekseenko,Borodkin,Etmetchenko
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- Ni-SMTU@boehmite: As an efficient and recyclable nanocatalyst for oxidation reactions
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Boehmite nanoparticles were prepared via a simple and inexpensive procedure in water using commercially available materials, and furthermore a novel type of recoverable nanocatalyst was prepared via immobilization of the S-methylisothiourea complex of nickel on the surface of boehmite nanoparticles (Ni-SMTU@boehmite). This organometallic catalyst was characterized by FT-IR spectroscopy, TGA, XRD, ICP-OES, EDS and SEM techniques. Ni-SMTU@boehmite was applied as an efficient, recoverable and stable heterogeneous organometallic catalyst for the selective oxidation of sulfides to sulfoxides and oxidative coupling of thiols to corresponding disulfides. Metal leaching and heterogeneity test of this catalyst was examined by the ICP-OES technique, which showed that this catalyst can be recovered and reused for several times without significant loss of its catalytic efficiency or nickel leaching.
- Ghorbani-Choghamarani, Arash,Moradi, Parisa,Tahmasbi, Bahman
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- Highly Efficient Oxidative Coupling of Thiols and Oxidation of Sulfides in the Presence of MCM-41@Tryptophan-Cd and MCM-41@Tryptophan-Hg as Novel and Recoverable Nanocatalysts
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Abstract: Two heterogeneous catalysts, MCM-41@Tryptophan-Cd and MCM-41@Tryptophan-Hg, were synthesized by immobilization of Cd or Hg complexes on MCM-41 as novel, efficient, recoverable and stable nanocatalysts for Oxidation of sulfides to sulfoxides and
- Molaei, Somayeh,Tamoradi, Taiebeh,Ghadermazi, Mohammad,Ghorbani-Choghamarani, Arash
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- An efficient clean methodology for the C-S coupling to aryl thioethers and S-S homocoupling to aromatic disulfides catalyzed over a Ce(IV)-leucine complex immobilized on mesoporous MCM-41
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A novel Ce(iv)-anchored l-leucine covalently bonded to mesoporous MCM-41 has been synthesized by a non-hydrothermal post-functionalization approach. It has been thoroughly characterized by sophisticated physicochemical techniques. The material was applied in the efficient green synthesis of aromatic sulfides by C-S coupling using molecular sulfur and haloarenes. Another catalytic application was in the synthesis of symmetric disulfides by the homocoupling of aromatic thiols in the presence of H2O2 as an oxidant. The ligand-free protocol is simple, clean and free from hazardous chemicals. Moreover, the catalyst is reusable for several times, thus making the methodology sustainably viable.
- Veisi, Hojat,Tamoradi, Taibeh,Karmakar, Bikash
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- Immobilization of a nickel complex onto functionalized Fe3O4 nanoparticles: a green and recyclable catalyst for synthesis of 5-substituted 1H-tetrazoles and oxidation reactions
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Abstract: In the present research, a magnetically recoverable catalyst was easily prepared by anchoring nickel onto the surface of organically modified magnetite nanoparticles. Characterization of the prepared nanostructure was performed by various physico-chemical techniques such as Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, thermal gravimetric analysis and vibrating sample magnetometer measurements. The catalytic behavior of the prepared nanohybrid as an efficient catalyst was successfully probed in the oxidation of sulfides, oxidative coupling of thiols and synthesis of 5-substituted 1H-tetrazoles. This method was found to have significant advantages, including high yield, green reaction conditions, short reaction time, easy separation and workup, as well as the ability to tolerate a wide variety of substitutions in the reagents. Graphical Abstract: [Figure not available: see fulltext.].
- Tamoradi, Taiebeh,Mehraban-Esfandiari, Bita,Ghadermazi, Mohammad,Ghorbani-Choghamarani, Arash
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- Oxidative coupling of thiols in solution and under solvent-free conditions
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A mild and efficient method for the oxidative coupling of thiols by ammonium dichromate in the presence of silica chloride and wet SiO2 in solution and under solvent free conditions is reported.
- Shirini, Farhad,Zolfigol, Mohammad A.,Khaleghi, Mahroo
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- Cu (II) and Cd (II) anchored functionalized mesoporous SBA-15 as novel, highly efficient and recoverable heterogeneous catalysts for green oxidative coupling of thiols and C–S cross-coupling reaction of aryl halides
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Two novel heterogeneous catalysts have been synthesized by anchoring Cu and Cd Creatinine complexes onto the surface of mesochannels of SBA-15 for highly efficient oxidative coupling of thiols to disulfides using hydrogen peroxide and synthesis of sulfides using S8 and KOH. The structure of the prepared catalysts was determined using SEM, FT-IR, X-ray diffraction, elemental analysis, N2 adsorption–desorption analysis and TGA. The catalysts significantly enhanced the reaction rate of the oxidative coupling of thiols and C–S bond formations. The catalysts were reused several times without appreciable loss in their activity.
- Molaei, Somayeh,Tamoradi, Taiebeh,Ghadermazi, Mohammad,Ghorbani-Choghamarani, Arash
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- Synthesis of hierarchical mesoporous Mn-MFi zeolite nanoparticles: A unique architecture of heterogeneous catalyst for the aerobic oxidation of thiols to disulfides
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An efficient procedure for aerobic oxidation of thiols to disulfides catalyzed by new self-assembled hierarchical mesoporous Mn-MFI in the presence of air under solvent-free conditions as well as in aqueous medium is reported. The mesoporosity and Mn4+ loading, together with a highly crystalline microporous pore wall structure of the MFI framework were achieved through a newly designed hydrothermal process. This hydrothermal approach leads to hierarchical self-assembled mesoporous zeolite structures through isomorphous substitution of Si by Mn and Al. It is shown that Mn-containing mesoporous zeolites are capable to form disulfide bonds from thiols in the presence of air. The zeolitic materials were characterized by XRD, field-emission scanning electron microscopy, high-resolution TEM, X-ray photoelectron spectroscopy, 29Si NMR, 27Al NMR, and EPR spectroscopy, as well as AAS analysis and N2 sorption studies. N2 sorption analysis revealed high surface areas and narrow pore size distributions (1.2-6.0 nm) for different samples. The mesoporous Mn-ZSM-5 acted as an efficient heterogeneous catalyst with maximum catalytic activity in the benzenethiol conversion to diphenyldithiol. Copyright
- Patra, Astam K.,Dutta, Arghya,Pramanik, Malay,Nandi, Mahasweta,Uyama, Hiroshi,Bhaumik, Asim
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- Fabrication of La (III) supported on CoFe2O4 MNPs: a novel and efficient heterogeneous catalyst for selective oxidation of sulfides and synthesis of symmetrical disulfides
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Abstract: This paper reports the fabrication of La supported on CoFe2O4 nanoparticles through tryptophan (Trp) post-functionalization modification of CoFe2O4 which can be used as an efficient recyclable nanocata
- Ghadermazi, Mohammad,Moeini, Nazanin,Molaei, Somayeh
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- Synthesis and Characterization of Magnetic Functionalized Ni and Cu Nano Catalysts and Their Application in Oxidation, Oxidative Coupling and Various Multi-Component Reactions
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Abstract: Two magnetic nano catalysts of nickel and copper, Fe3O4@SiO2@DOP-BenPyr-M(II), (M=Ni and Cu) have been synthesized. These catalysts were applied as recoverable, efficient and new heterogeneous catalysts for the high yielding and room temperature one-pot procedure of selective oxidation of sulfides to sulfoxides and oxidative coupling of thiols to disulfides. In addition, the catalytic activity of Fe3O4@SiO2@DOP-BenPyr-Ni(II) was investigated as heterogeneous nanocatalyst for synthesis of 2,3-dihydroquinazolin-4(1H)-ones, 5-substituted 1H-tetrazoles and polyhydroquinolines. The synthesized catalysts were characterized by FT-IR, TGA, XRD, VSM, EDX, ICP and SEM techniques. These catalysts were recovered by an external magnet and reused several times without significant loss of catalytic efficiency. Graphic Abstract: [Figure not available: see fulltext.]
- Hajjami, Maryam,Sheikhaei, Shiva,Gholamian, Fatemeh,Yousofvand, Zakieh
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p. 2420 - 2435
(2021/01/04)
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- Preparation method of symmetric disulfide bond-containing compound
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The method comprises the following steps: adding a raw material and an oxidant to a reaction bottle containing a solvent; reacting 23W - 85W under the irradiation of 12 - 24h energy-saving lamps; and purifying the reaction product to obtain symmetrical disulfide bond-containing compounds. The raw material is mercaptan or thiophenol. The oxidizing agent is trichlorobromomethane, and the solvent is tetrahydrofuran. The method has the advantages of simple operation, high yield (70 - 90%), wide applicability, cheap and easily available raw materials, and provides a better way for the synthesis and production of symmetrical disulfide bond-containing compounds.
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Paragraph 0020; 0078-0080
(2021/11/21)
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- Copper based on diaminonaphthalene-coated magnetic nanoparticles as robust catalysts for catalytic oxidation reactions and C-S cross-coupling reactions
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In this work, the immobilization of copper(ii) on the surface of 1,8-diaminonaphthalene (DAN)-coated magnetic nanoparticles provides a highly active catalyst for the oxidation reaction of sulfides to sulfoxides and the oxidative coupling of thiols to disulfides using hydrogen peroxide (H2O2). This catalyst was also applied for the one-pot synthesis of symmetrical sulfidesviathe reaction of aryl halides with thiourea as the sulfur source in the presence of NaOH instead of former strongly basic and harsh reaction conditions. Under optimum conditions, the synthesis yields of sulfoxides, symmetrical sulfides, and disulfides were about 99%, 95%, and 96% respectively with highest selectivity. The heterogeneous copper-based catalyst has advantages such as the easy recyclability of the catalyst, the easy separation of the product and the less wastage of products during the separation of the catalyst. This heterogeneous nanocatalyst was characterized by FESEM, FT-IR, VSM, XRD, EDX, ICP and TGA. Furthermore, the recycled catalyst can be reused for several runs and is economically effective.
- Yarmohammadi, Nasrin,Ghadermazi, Mohammad,Mozafari, Roya
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p. 9366 - 9380
(2021/03/16)
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- A nickel nanoparticle engineered CoFe2O4/SiO2-NH2@carboxamide composite as a novel scaffold for the oxidation of sulfides and oxidative coupling of thiols
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The purpose of this work was to prepare a new Ni-carboxamide complex supported on CoFe2O4 nanoparticles (CoFe2O4/SiO2-NH2@carboxamide-Ni). The carboxamide host material unit generated cavities that stabilized the nickel nanoparticles effectively and preve
- Zohrevandi, Mina,Mozafari, Roya,Ghadermazi, Mohammad
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p. 14717 - 14729
(2021/05/19)
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- l-Arginine complex of copper on modified core–shell magnetic nanoparticles as reusable and organic–inorganic hybrid nanocatalyst for the chemoselective oxidation of organosulfur compounds
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In this paper, we report the fabrication and characterization of a stable heterogeneous nanostructure catalyst of copper immobilized on Fe3O4@SiO2@l-Arginine, for the oxidation of sulfides and oxidative coupling of thiols. The prepared nanocatalyst has been characterized by different techniques such as FTIR, XRD, SEM, TEM and TGA. These nanoparticles were the effective catalyst for selective oxidation of sulfides and oxidative coupling of thiols using 30% H2O2. The suggested method offers several prominent advantages such as mild condition, use of magnetically reusable catalyst, simple workup procedure, good to high yields of products and great selectivity.
- Nikoorazm, Mohsen,Moradi, Parisa,Noori, Nourolah,Azadi, Gouhar
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p. 467 - 478
(2020/09/01)
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- Synthesis and characterization of VO–vanillin complex immobilized on MCM-41 and its facile catalytic application in the sulfoxidation reaction, and synthesis of 2,3-dihydroquinazolin-4(1H)-ones and disulfides in green media
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In this work, a vanillin complex is immobilized onto MCM-41 and characterized by FT-IR, X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, thermogravimetric analysis, and BET techniques. This supported Schiff base complex was found to be an efficient and recoverable catalyst for the chemoselective oxidation of sulfides into sulfoxides and thiols into their corresponding disulfides (using hydrogen peroxide as a green oxidant) and also a suitable catalyst for the preparation of 2,3-dihydroquinazolin-4(1H)-one derivatives in water at 90°C. Using this protocol, we show that a variety of disulfides, sulfoxides, and 2,3-dihydroquinazolin-4(1H)-one derivatives can be synthesized in green conditions. The catalyst can be recovered and recycled for further reactions without appreciable loss of catalytic performance.
- Nikoorazm, Mohsen,Khanmoradi, Maryam
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p. 1477 - 1489
(2020/03/11)
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- Natural gallic acid catalyzed aerobic oxidative coupling with the assistance of MnCO3 for synthesis of disulfanes in water
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The formation of S-S bonds has great significance and value in synthetic chemistry and bioscience. To pursue a sustainable approach for such a synthesis, an aerobic oxidative coupling method for the efficient preparation of organic disulfanes, using a low-toxic natural gallic acid as an organocatalyst, inexpensive MnCO3 as a cocatalyst, O2 as the terminal oxidant and water as the solvent, has been successfully developed. Such metal-organic cooperative catalytic protocol provided an access to various symmetrical and unsymmetrical disulfanes in up to 99% yield. Gram scale synthesis with practical convenience and low loading of catalysts further illustrates the practicability of our method.
- Song, Lijuan,Li, Wenhao,Duan, Wenxue,An, Jichao,Tang, Shanyu,Li, Longjia,Yang, Guanyu
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supporting information
p. 1432 - 1438
(2019/03/26)
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- Mild and highly efficient method for the oxidation of sulfides and oxidative coupling of thiols catalyzed by Fe3O4@MCM-41@VO-SPATB as efficient and magnetically recoverable nanocatalyst
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The use of oxo vanadium complex with s-propyl-2-aminobenzothioate ligand immobilized onto functionalized magnetic nanoporous MCM-41(Fe3O4@MCM-41@VO-SPATB) as efficient and magnetically recoverable nanocatalyst for oxidation of sulfides into sulfoxides and oxidative coupling of thiols into disulfides using H2O2 as green oxidant is presented. This method provides much improved modification of oxidation reactions in terms of mild reaction conditions, short reaction time and good-to-excellent yields of products. Another important feature of this method is the ability to reuse the magnetite nanocatalyst for several times with no loss of its catalytic activity.
- Nikoorazm, Mohsen,Ghorbani, Farshid,Ghorbani-Choghamarani, Arash,Erfani, Zahra
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p. 553 - 562
(2019/02/17)
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- La complex supported on magnetic nanoparticles: green, efficient, novel and reusable nanocatalyst for the synthesis of 5-substituted tetrazoles and the oxidation reactions in neat condition
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In the present work, we were interested in the synthesis of green and novel magnetic nanocatalyst by anchoring La complex on Fe3O4. The nanocatalyst was successfully synthesized and characterized by FT-IR, SEM, TGA, XRD, EDX, and ICP techniques. The designed procedure shows many benefits such as short reaction time, high yield, excellent purity, eco-friendly catalyst, easy workup and easy recovery from the reaction mixture by external magnet. [Figure not available: see fulltext.].
- Tamoradi, Taiebeh,Irandoust, Asrin,Ghadermazi, Mohammad
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p. 1723 - 1733
(2019/07/03)
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- A synthesis of sulfoxides and disulfides under classical and ultrasonic conditions in presence of recoverable inorganic–organic hybrid magnetism nanocatalysts Fe3O4@Tryptophan-M (M: Cu, Co and Fe)
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Three inorganic–organic hybrid magnetic nanocatalysts have been reported as new catalysts for the synthesis of sulfoxides and disulfides. Also, the effect of ultrasound irradiation on the synthesis of sulfoxides and disulfides was checked. The time of rea
- Moeini, Nazanin,Ghadermazi, Mohammad,Ghorbani-Choghamarani, Arash
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p. 278 - 286
(2019/06/25)
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- Biocatalytic synthesis of diaryl disulphides and their bio-evaluation as potent inhibitors of drug-resistant Staphylococcus aureus
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Staphylococcus aureus is a WHO Priority II pathogen for its capability to cause acute to chronic infections and to resist antibiotics, thus severely impacting healthcare systems worldwide. In this context, it is urgently desired to discover novel molecules to thwart the continuing emergence of antimicrobial resistance. Disulphide containing small molecules has gained prominence as antibacterials. As their conventional synthesis requires tedious synthetic procedure and sometimes toxic reagents, a green and environmentally benign protocol for their synthesis has been developed through which a series of molecules were obtained and evaluated for antibacterial activity against ESKAPE pathogen panel. The hit compound was tested for cytotoxicity against Vero cells to determine its selectivity index and time-kill kinetics was determined. The activity of hit was determined against a panel of S. aureus multi-drug resistant clinical isolates. Also, its ability to synergize with FDA approved drugs was tested as was its ability to reduce biofilm. We identified bis(2-bromophenyl) disulphide (2t) as possessing equipotent antimicrobial activity against S. aureus including MRSA and VRSA strains. Further, 2t exhibited a selectivity index of 25 with concentration-dependent bactericidal activity, synergized with all drugs tested and significantly reduced preformed biofilm. Taken together, 2t exhibits all properties to be positioned as novel scaffold for anti-staphylococcal therapy.
- Saima,Soni, Isha,Lavekar, Aditya G.,Shukla, Manjulika,Equbal, Danish,Sinha, Arun K.,Chopra, Sidharth
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p. 171 - 178
(2019/01/04)
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- Fenton-Inspired C-H Functionalization: Peroxide-Directed C-H Thioetherification
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Substoichiometric iron mediates the thioetherification of unactivated aliphatic C-H bonds directed by resident silylperoxides. Upon exposure to a catalytic amount of iron(II) triflate, TIPS-protected peroxides bearing primary, secondary, and tertiary C-H sites undergo chemoselective thioetherification of remote C-H bonds with diaryl disulfides. The reaction demonstrates a broad substrate scope and functional group tolerance without the use of any noble metal additives. Mechanistic experiments suggest that the reaction proceeds through 1,5-H atom abstraction by a hydroxyl radical generated with iron.
- Groendyke, Brian J.,Modak, Atanu,Cook, Silas P.
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p. 13073 - 13091
(2019/10/10)
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- Fe3O4@S-ABENZ@VO: Magnetically separable nanocatalyst for the efficient, selective and mild oxidation of sulfides and oxidative coupling of thiols
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Oxovanadium(IV) immobilized on Fe3O4@S-ABEN is reported as a highly efficient nanocatalyst for the oxidation of sulfides and oxidative coupling of thiols (using H2O2 as green oxidant), the products of which are obtained in high to excellent yields. The products can be separated by a simple extraction with organic solvent and the catalyst is highly efficient, especially in terms of selectivity of desired product. The catalytic system can be recycled and reused without significant loss of catalytic activity.
- Rezaei, Somaieh,Ghorbani-Choghamarani, Arash,Badri, Rashid,Nikseresht, Ahmad
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- Anchoring Ni (II) on Fe3O4@tryptophan: A recyclable, green and extremely efficient magnetic nanocatalyst for one-pot synthesis of 5-substituted 1H-tetrazoles and chemoselective oxidation of sulfides and thiols
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A green, novel and extremely efficient nanocatalyst was successfully synthesized by the immobilization of Ni as a transition metal on Fe3O4 nanoparticles coated with tryptophan. This nanostructured material was characterized using Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, thermogravimetric analysis, inductively coupled plasma optical emission spectroscopy, vibrating sample magnetometry and X-ray diffraction. The prepared nanocatalyst was applied for the oxidation of sulfides, oxidative coupling of thiols and synthesis of 5-substituted 1H-tetrazoles. The use of non-toxic, green and inexpensive materials, easy separation of magnetic nanoparticles from a reaction mixture using a magnetic field, efficient and one-pot synthesis, and high yields of products are the most important advantages of this nanocatalyst.
- Moeini, Nazanin,Tamoradi, Taiebeh,Ghadermazi, Mohammad,Ghorbani-Choghamarani, Arash
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- Nickel Schiff base complex anchored on Fe3O4@MCM-41 as a novel and reusable magnetic nanocatalyst and its application in the oxidation of sulfides and oxidative coupling of thiols using H2O2
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A novel and reusable nanocatalyst was synthesized by anchoring a nickel Schiff base complex onto Fe3O4@MCM-41 (Fe3O4@MCM-41@Ni-P2C) and characterization was accomplished with Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), powder X-ray diffraction (XRD), vibrating sample magnetometry (VSM), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic absorption spectroscopy (AAS) techniques. This catalytic system was efficiently used for oxidation of sulfides to sulfoxides and oxidative coupling of thiols to corresponding disulfides using H2O2 as green oxidant at room temperature. These reactions were carried out in a green solvent (ethanol) and/or under solvent-free conditions with short reaction time, complete selectivity and very high conversion under mild reaction conditions. More importantly, separation and recycling of this magnetic catalyst can be easily done through a simple and low cost magnetic separation process.
- Nikoorazm, Mohsen,Ghorbani, Farshid,Ghorbani-Choghamarani, Arash,Erfani, Zahra
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p. 552 - 561
(2018/04/26)
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- Synthesis and characterization of sulfamic acid supported on Fe3O4 nanoparticles: A green, versatile and magnetically separable acidic catalyst for oxidation reactions and Knoevenagel condensation
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Sulfamic acid immobilized on diethylenetriamine functionalized Fe3O4 nanoparticles (SA-DETA-Fe3O4) was successfully prepared and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM), thermo gravimetric analysis (TGA), X-Ray diffraction (XRD) and scanning electron microscopy (SEM). The sulfamic acid was found as a magnetically separable and highly active catalyst for the oxidative coupling thiols, oxidation of sulfides. Furthermore, the SA-DETA-Fe3O4 showed the high catalytic activity in Knoevenagel condensation of aromatic aldehydes with active methylene compounds (malononitrile and ethyl cynoacetate). The nanosolid catalyst could be easily recovered by a simple magnetic separation and reused for many cycles without deterioration in catalytic activity.
- Shiri, Lotfi,Narimani, Hojatollah,Kazemi, Mosstafa
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- Synthesis and characterization of oxo-vanadium complex anchored onto SBA-15 as a green, novel and reusable nanocatalyst for the oxidation of sulfides and oxidative coupling of thiols
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Abstract: The present work describes the synthesis of a new oxo-vanadium complex immobilized on SBA-15 nanostructure as an efficient catalyst for oxidation of sulfides and oxidative coupling of thiols. Characterization of the resultant AMPD@SBA-15 nanostructure was performed by various physico-chemical techniques such as Fourier transform infrared spectroscopy, transmission and scanning electron microscopies, energy-dispersive X-ray spectroscopy, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, thermal gravimetric analysis, and N2 adsorption and desorption. The results of the developed procedure bring several benefits such as the use of commercially available, ecologically benign, operational simplicity, and cheap and chemically inert reagents. It shows good reaction times, practicability and high efficiency, and is easily recovered from the reaction mixture by simple filtration and reused for several consecutive cycles without noticeable change in its catalytic activity. More importantly, high efficiency, simple and an inexpensive procedure, commercially available materials, easy separation, and an eco-friendly procedure are the several advantages of the currently employed heterogeneous catalytic system.
- Tamoradi, Taiebeh,Ghadermazi, Mohammad,Ghorbani-Choghamarani, Arash,Molaei, Somayeh
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p. 4259 - 4276
(2018/03/21)
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- Highly efficient, green, rapid, and chemoselective oxidation of sulfur-containing compounds in the presence of an MCM-41@creatinine@M (M = la and Pr) mesostructured catalyst under neat conditions
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In the present study, we report the synthesis of two green recoverable catalysts by covalent linking of the creatinine La and Pr complexes on an MCM-41 mesostructure with the commercially available materials and via a simple and inexpensive procedure. These heterogeneous catalysts were characterized by Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, scanning electron microscopy, N2 adsorption and desorption, inductively coupled plasma optical emission spectroscopy, and thermogravimetric analysis. The obtained mesostructures act as active and reusable catalysts for the oxidation of sulfides and oxidative coupling of thiols under neat conditions. More importantly, significant practical advantages of this environmentally friendly process include high efficiency, good reaction times, and convenient recovery and reusability for several times without any significant loss of activity of the catalyst.
- Tamoradi, Taiebeh,Ghadermazi, Mohammad,Ghorbani-Choghamarani, Arash
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p. 5479 - 5488
(2018/03/30)
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- Synthesis of new zirconium complex supported on MCM-41 and its application as an efficient catalyst for synthesis of sulfides and the oxidation of sulfur containing compounds
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In the present work, we report synthesis of new zirconium complex supported on mesoporous silica by anchoring of adenine on the wall of functionalized MCM-41, then reacted with ZrOCl2. The resultant MCM-41-Adenine-Zr was characterized by FT-IR, XRD, TEM, SEM, TGA, EDX, ICP and BET techniques. It was exhibited that the MCM-41-Adenine-Zr can be used as an efficient and thermally stable nanocatalyst for the oxidation of sulfides, oxidative coupling of thiols and synthesis of sulfides. Moreover, this heterogeneous catalyst can be easily recovered from the reaction mixture by simple filtration and reused for several consecutive cycles without noticeable change in its catalytic activity.
- Tamoradi, Taiebeh,Ghorbani-Choghamarani, Arash,Ghadermazi, Mohammad
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- Fe3O4-AMPD-Pd: A novel and efficient magnetic nanocatalyst for synthesis of sulfides and oxidation reactions
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A novel magnetic nanoparticle was synthesized with effective catalytic properties and recyclable ability. This heterogeneous nanocatalyst was identified using Fourier transform infrared, scanning electron microscopies, X‐ray diffraction, vibrating sample magnetometer, inductively coupled plasma atomic emission spectroscopy and thermogravimetric analysis methods. The nanocatalyst was used for the synthesis of the one-pot C–S coupling synthesis of sulfide in the presence of KOH, S8 as the sulfur source in DMSO as the solvent at 100 °C. Also, the oxidation of sulfides to sulfoxides and oxidative coupling of thiols to disulfides in the presence of the catalyst was tested. The catalyst has unique properties such as ability of magnetic separation from the reaction, high repeatability, and high thermal and chemical stability.
- Tamoradi, Taiebeh,Moeini, Nazanin,Ghadermazi, Mohammad,Ghorbani-Choghamarani, Arash
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p. 104 - 109
(2018/07/29)
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- Ni(II)-Adenine complex coated Fe3O4 nanoparticles as high reusable nanocatalyst for the synthesis of polyhydroquinoline derivatives and oxidation reactions
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In the present study, Fe3O4 nanoparticles were prepared via simple and versatile procedure. Then, a novel and green catalyst was synthesized by the immobilization of Ni on Fe3O4 nanoparticles coated with adenine. The activity of this nanostructure compound was examined for the oxidation of sulfides, oxidative coupling of thiols and synthesis of polyhydroquinolines. The prepared catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray Diffraction (XRD), thermal gravimetric analysis (TGA), and vibrating sample magnetometer (VSM) measurements. This organometallic catalyst was recovered by the assistance of an external magnetic field from the reaction mixture and reused for seven continuous cycles without noticeable change in its catalytic activity.
- Tamoradi, Taiebeh,Ghadermazi, Mohammad,Ghorbani-Choghamarani, Arash
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- A novel dual-nano assisted synthesis of symmetrical disulfides from aryl/alkyl halides
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Here, we have reported a novel approach towards dual-nano assisted synthesis of disulfides from coupling of alkyl/aryl halides and sulfur nanoparticles. The indium oxide nanoparticles as catalyst expedite the conversion and sulfur nanoparticle notably enhances the miscibility, providing a faster, high yielding and cost-effective process in ethanol-water system. The method has synthetic advantages in terms of mild reaction framework, catalyst regeneration, and absence of any sulfide or polysulfide linkage as by-product leading to a column free synthesis. A variety of alkyl, aryl and heteroaryl symmetrical disulfides are obtained in good to excellent yields up to exceeding 98%.
- Devi, Namita,Hazarika, Sukanya,Gogoi, Prasanta,Barman, Pranjit
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supporting information
p. 1927 - 1938
(2018/07/21)
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- Synthesis of Fe3O4@SiO2@DOPisatin-Ni(II) and Cu(II) nanoparticles: Highly efficient catalyst for the synthesis of sulfoxides and disulfides
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The catalytic activity of two magnetic catalysts Fe3O4@SiO2@DOPisatin-M(II) (M?=?Ni, Cu) was investigated in the environmentally green H2O2 oxidant-based oxidation of sulfides to sulfoxides and oxidative coupling of thiols to disulfides. By using these catalysts, various substrates were successfully converted into their corresponding product. These catalysts could also be reused multiple time without significant loss of activity. The physical and chemical properties of the catalysts were determined using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), energy dispersive X-ray spectroscopy (EDX) and atomic absorption spectroscopy (AAS).
- Hajjami, Maryam,Sharifirad, Fatemeh,Gholamian, Fatemeh
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- Synthesis and characterization of tribenzyl ammonium-tribromide supported on magnetic Fe3O4 nanoparticles: a robust magnetically recoverable catalyst for the oxidative coupling of thiols and oxidation of sulfides
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Abstract: Taking into account the principles of green chemistry, magnetic nanoparticles, especially Fe3O4 nanoparticles, open up a new chapter in modern organic synthesis to inset a fascinating, stupendous and efficient catalytic strategy for facilitating catalyst recovery in various chemical reactions. Inspired by this topic, tribenzyl ammonium-tribromide immobilized on magnetic nanoparticles (Fe3O4–TBA-Br3) as a bromine source was successfully synthesized and its catalytic activity in the oxidative coupling of thiols and oxidation of sulfides was investigated. It is the first report on the use of the immobilized bromine source on Fe3O4 nanoparticles as a nanomagnetic recyclable catalyst for the oxidative coupling of thiols. The nanosolid catalyst could be easily recovered by a simple magnetic separation and reused for several cycles without significant degradation in catalytic activity. Graphical Abstract: [Figure not available: see fulltext.]
- Shiri, Lotfi,Ghorbani-Choghamarani, Arash,Kazemi, Mosstafa
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p. 2707 - 2724
(2017/04/18)
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- Cu(II) immobilized on Fe3O4–diethylenetriamine: A new magnetically recoverable catalyst for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones and oxidative coupling of thiols
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Cu(II) immobilized on Fe3O4–diethylenetriamine was designed as a new, inexpensive and efficient heterogeneous catalyst for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones and the oxidative coupling of thiols. The structure of the nanomagnetic catalyst was comprehensively characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, vibrating sample magnetometry, thermogravimetric analysis, X-ray diffraction and atomic absorption spectroscopy. Simple preparation of the catalyst from commercially available materials, high catalytic activity, simple operation, high yields, use of green solvents, easy magnetic separation and reusability of the catalyst with unaltered activity make our protocol a green and feasible synthetic strategy.
- Shiri, Lotfi,Ghorbani-Choghamarani, Arash,Kazemi, Mosstafa
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- Synthesis and anti-bacterial activity of a library of 1,2-benzisothiazol-3(2H)-one (BIT) derivatives amenable of crosslinking to polysaccharides
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1,2-Benzisothiazol-3(2H)-one (BIT) is one of the most common chemical biocides in industrial products, with a heterocyclic structure and a wide range of antimicrobial activity. A library of BIT derivatives was synthesized and characterized, from which 18 compounds were selected, tested for anti-bacterial activity relative to the parent molecule and amenable of coupling to plant polysaccharides in general and to galactomannans (GM) in particular, widely used as rheology modifiers, but with limited “biostability”. Four sites on the BIT core were targeted: the nitrogen and the oxygen atoms on the heterocyclic ring, the C5 and the C6 positions on the aromatic ring, where functional groups were introduced. The ultimate aim of this work is to establish whether by covalently linking a biocide to GM polymers, their “biostability” can be improved.
- Viani, Fiorenza,Rossi, Bianca,Panzeri, Walter,Merlini, Luca,Martorana, Alessandra M.,Polissi, Alessandra,Galante, Yves M.
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p. 1745 - 1761
(2017/03/08)
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- Fe3O4 MNPs-DETA/Benzyl-Br3: A new magnetically reusable catalyst for the oxidative coupling of thiols
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We report a new strategy to immobilize a bromine source on the surface of magnetic Fe3O4 nanoparticles (Fe3O4 MNPs-DETA/Benzyl-Br3) leading to amagnetically recoverable catalyst, which exhibits high catalytic efficiency in oxidative coupling of thiols to the disulfides (89–98%). The Fe3O4 MNPs-DETA/Benzyl-Br3 catalyst was fabricated by anchoring 3-chloropropyltrimethoxysilane (CPTMS) onmagnetic Fe3O4 nanoparticles, followed with N-benzylation and reaction with bromine in tetrachloridecarbon. The resulting nanocomposite was analyzed by a series of characterization techniques such as FT-IR, SEM, TGA, VSM and XRD. The catalyst could be recovered viamagnetic attraction and could be recycled at least 5 times without appreciable decrease in activity.
- Shiri, Lotfi,Kazemi, Mosstafa
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p. 1171 - 1176
(2017/09/27)
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- Oxidative dimerization of thiols to disulfide using recyclable magnetic nanoparticles
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Abstract: Dimerization of thiol groups to disulfide is an important transformation in chemical processes. In this study, magnetic ion exchanged Montmorillonite-k10 was synthesized and characterized using FTIR, X-ray diffraction and scanning electron microscope techniques. Then, the application of the synthesized catalyst as an efficient oxidizing agent was evaluated in oxidative dimerization of different thiols to corresponding disulfides under optimal reaction conditions. The reaction was easily performed with aromatic, aliphatic and heterocyclic thiols. The magnetic catalyst was easily recovered by applying an external magnet and, further, was reused in successive reactions. Graphical Abstract: [Figure not available: see fulltext.]
- Masnabadi, Nasrin,Ghasemi, Mohammad Hadi,Beyki, Mostafa Hossein,Sadeghinia, Mohammad
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p. 1609 - 1618
(2017/02/15)
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- 3,6-Di(pyridin-2-yl)-1,2,4,5-tetrazine (pytz) mediated metal-free mild oxidation of thiols to disulfides in aqueous medium
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Thiols are efficiently oxidized to disulfides (RSSR) in the presence of 3,6-di(pyridin-2-yl)-1,2,4,5-tetrazine (pytz) in aqueous medium, as well as in the absence of a solvent under mild and metal-free conditions. A broad range of alkyl, aryl and heterocyclic symmetrical disulfides can be easily obtained in almost quantitative yields. The X-ray single crystal structure of 2-aminocyclopent-1-ene-1-carbothioic dithioperoxyanhydride (disulfide obtained from 2-aminocyclopentene-1-dithiocarboxylic acid, ACDA) is reported. The reaction mechanism has been studied thoroughly. It is shown that the reaction proceeds through the formation of an organosulphur radical. Pytz interacts with thiol to accept one electron and produces an organosulphur radical. Pytz ultimately accepts two electrons to form H2pytz and is capable of oxidizing 2 equivalents of thiols.
- Samanta, Suvendu,Ray, Shounak,Ghosh, Abhisek Brata,Biswas, Papu
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p. 39356 - 39363
(2016/06/01)
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- Efficient preparation of boehmite silica dopamine sulfamic acid as a novel nanostructured compound and its application as a catalyst in some organic reactions
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A novel type of recoverable boehmite nanocatalyst was prepared via immobilization of dopamine on the surface of boehmite followed by coating with silica and reacting with chlorosulfunic acid to obtain boehmite silica dopamine sulfamic acid (boehmite-Si-DSA). This compound was characterized by FT-IR spectroscopy, TGA, XRD, TEM and SEM techniques. Boehmite-Si-DSA was used as an efficient, recoverable and thermally stable heterogeneous nanocatalyst for the preparation of 2,3-dihydroquinazolin-4(1H)-one, sulfoxides and disulfides. The catalyst was recovered by simple filtration and reused several times without significant loss of catalytic efficiency.
- Hajjami, Maryam,Ghorbani-Choghamarani, Arash,Ghafouri-Nejad, Raziyeh,Tahmasbi, Bahman
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p. 3066 - 3074
(2016/05/09)
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- Boehmite silica sulfuric acid: as a new acidic material and reusable heterogeneous nanocatalyst for the various organic oxidation reactions
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In this research, project boehmite silica sulfuric acid (Boehmite-SSA) has been applied as new acidic porous catalyst for the selective oxidation of sulfides to sulfoxides and oxidative coupling of thiols to corresponding disulfides using hydrogen peroxide as oxidizing agent. The products have been obtained in short reaction times and high yields. Boehmite nanoparticles was prepared, coated by silica and then reacted with chlorosulfuric acid to obtain Boehmite-SSA. This catalyst was characterized by FT-IR, TGA/DTA, XRD, TEM, SEM, EDS and BET techniques. BET curve of boehmite nanoparticles identified as a typical type IV isotherm (definition by IUPAC), which are the characteristics of mesoporous material. Nitrogen adsorption/desorption measurement indicated that boehmite nanoparticles had BET surface area of about 122.8?m2/g. The catalyst was easily separated and reused for the several runs without significant loss of its catalytic efficiency.
- Ghorbani-Choghamarani, Arash,Hajjami, Maryam,Tahmasbi, Bahman,Noori, Nourolah
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p. 2193 - 2202
(2016/11/06)
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- Preparation of DSA@MNPs and application as heterogeneous and recyclable nanocatalyst for oxidation of sulfides and oxidative coupling of thiols
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Abstract: Dopamine sulfamic acid-functionalized magnetic Fe3O4 nanoparticles (DSA@MNPs) were prepared by a very simple and inexpensive procedure using commercial materials and characterized by X-ray diffraction (XRD) analysis, thermogravimetric analysis (TGA), Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and vibrating-sample magnetometry (VSM) techniques. They were employed as an efficient and recoverable catalyst in oxidation of sulfides to sulfoxides and oxidative coupling of thiols to disulfides using hydrogen peroxide as green oxidant at room temperature. This is the first report of application of DSA@MNPs in organic reactions. The supported magnetic nanoparticles could be easily recovered using an appropriate external magnet, minimizing catalyst loss during separation, and reused for several times without any loss of catalytic activity. Also, the amount of sulfamic acid function in the DSA@MNPs was calculated from ion-exchange pH analysis and back titration. Graphical abstract: [Figure not available: see fulltext.]
- Ghorbani-Choghamarani, Arash,Rabiei, Hossein,Tahmasbi, Bahman,Ghasemi, Banoo,Mardi, Farideh
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p. 5723 - 5737
(2016/06/01)
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- Synthesis and characterization of Co (II) and Fe (III) Schiff base complexes grafted onto mesoporous MCM-41: A heterogeneous and recyclable nanocatalysts for the selective oxidation of sulfides and oxidative coupling of thiols
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Novel organic–inorganic hybrid heterogeneous catalysts containing cobalt(II) and iron(III) Schiff base complexes, grafted on the internal surface of MCM-41 pores were prepared by introducing a metal salt into a mesoporous silica functionalized with a Schiff base ligand. The chemical and physical properties of the catalysts were investigated by BET, TGA, XRD, FT-IR, and TEM techniques. These complexes were found to be efficient, selective catalysts for the oxidation of various sulfides to sulfoxides and oxidative coupling of thiols to their corresponding disulfides with urea hydrogen peroxide in excellent yield at room temperature. The designed catalytic system prevents effectively the overoxidation of sulfides and thiols to sulfoxides and sulfones, respectively. Also the heterogeneous catalysts can be recovered easily and reused many times without significant loss of activity and selectivity.
- Noori, Nourolah,Nikoorazm, Mohsen,Ghorbani-Choghamarani, Arash
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p. 1388 - 1395
(2016/09/28)
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- Synthesis, characterization, and catalytic application of Cr and Mn Schiff base complexes immobilized on modified nanoporous MCM-41
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Immobilization of chromium and manganese Schiff base complexes by postgrafting of ligand then metal salts on the walls of mesoporous MCM-41 functionalized with (3-aminopropyl)triethoxysilane is described. Characterization of the resulting heterogeneous catalysts by Fourier-transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis, and Brunauer–Emmett–Teller (BET) techniques indicated successful grafting of these two complexes inside the nanochannels of MCM-41. The complexes were found to be efficient, selective catalysts for oxidation of various sulfides to sulfoxides and oxidative coupling of thiols to corresponding disulfides using H2O2 as oxidant at room temperature. The recycling results of these heterogeneous catalysts showed good recyclability without significant loss of activity or selectivity in successive runs, indicating that the Cr and Mn Schiff base complexes supported on nanoporous MCM-41 remained intact and the coordination environments were not altered during the reaction.
- Nikoorazm, Mohsen,Ghorbani-Choghamarani, Arash,Noori, Nourolah
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p. 4621 - 4640
(2016/07/06)
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- Sulfamic acid-functionalized nano-titanium dioxide as an efficient, mild and highly recyclable solid acid nanocatalyst for chemoselective oxidation of sulfides and thiols
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A highly efficient and retrievable titanium dioxide-based nanocatalyst has been synthesized by covalent grafting of chlorosulfonic acid on amine-functionalized titania as a novel inorganic-organic hybrid heterogeneous nanocatalyst, which was characterized by Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The acid strength of the catalyst was determined by pH analysis and the Hammett acidity function. The potential of the resultant nanocatalyst was effectively evaluated for the chemoselective oxidation of sulfides to sulfoxides and thiols to disulfides using 30% H2O2 as an oxidant at room temperature under solvent-free conditions, which led to high conversion rates and yields. Optimization of the reaction conditions was studied by central composite design (CCD), which is one of the most widely used response surface methodologies. The catalyst can be easily recycled up to 10 times without significant decrease in catalytic activity, which makes it a promising catalyst for practical and large-scale applications. This work is the first report that uses 2,4-toluene diisocyanate as a linker for immobilizing liquid acid on a support.
- Tabrizian, Elham,Amoozadeh, Ali,Rahmani, Salman
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p. 21854 - 21864
(2016/03/08)
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- An efficient and convenient method for the preparation of disulfides from thiols using oxygen as oxidant catalyzed by tert-butyl nitrite
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An efficient and convenient tert-butyl nitrite-catalyzed selective aerobic oxidation of thiols has been developed. Under the optimal reaction conditions, a number of thiol derivatives including aromatic thiols, heteroaromatic thiols and aliphatic thiols can be converted into their corresponding disulfides in good to excellent yields.
- Yi, Shan-Li,Li, Mei-Chao,Hu, Xin-Quan,Mo, Wei-Min,Shen, Zhen-Lu
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p. 1505 - 1508
(2016/09/23)
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- Symmetrical disulfide synthesis via nickel-catalysis using potassium sulfide as sulfur source
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Abstract: An efficient one-pot method for the synthesis of organic disulfides from aryl and alkyl halides and potassium sulfide has been described. K2S acts as an inexpensive and readily available sulfur source. A variety of symmetric diaryl and dialkyl disulfides was prepared in good to excellent yields using NiCl2·6H2O and acetylacetone as the catalytic system. Graphical abstract: [Figure not available: see fulltext.]
- Soleiman-Beigi, Mohammad,Arzehgar, Zeinab
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p. 1759 - 1763
(2016/09/28)
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