- Kinetics and Mechanisms of the Reduction of Cobalt(II) 4,4',4'',4'''-Tetrasulfophthalocyanine by 2-Mercaptoethanol under Anoxic Conditions
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The kinetics and mechanism of reduction of cobalt(II) 4,4',4'',4'''-tetrasulfophthalocyanine by 2-mercaptoethanol to yield cobalt(I) tetrasulfophthalocyanine and 2-hydroxyethyl disulfide under anoxic conditions were investigated and the following rate law was found: ν = -dIITSP>T/dt = 2K1TIITSP>T>/H+/Ka1 + Ka2/aH+)(1 + αT)>, where k2 is a rate constant for the rate-limiting electron-transfer step, and K1 is the equilibrium constant for the complexation of a CoTSP dimer with thioethanol; Ka1 and Ka2 are the apparent acid dissociation constants of HOC2H4SH and HOC2H4S-, respectively; α is K1/(1 + aH+/Ka1 + Ka2/aH+); aH+ is the hydrogen ion activity.A nonlinear least-squares fit of the experimental data to the above rate law gave k2 = 228 +/- 3.8 s-1 and K1 = 117 +/- 2.5 M-1 at 27 deg C at μ = 0.4 M.
- Leung, Ping-Sang K.,Betterton, Eric A.,Hoffmann, Michael R.
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- Chalcogen-containing analogs of ethylene glycol and its derivatives
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Ethylene chlorohydrin when reacted with elemental chalcogens or dimethyl dichalcogenides in the hydrazine hydrate-alkali system forms chalcogen-containing analogs of ethylene glycol and its derivatives (dichalcogenated β-diglycols, chalcogenated ethanols, and chalcogenated methyl cellosolves).
- Vshivtsev,Levanova,Grabel'nykh,Sukhomazova,Albanov,Klyba,Zhanchipova,Russavskaya,Kochervin
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- Sulfonated Co(II) phthalocyanines covalently anchored at organic polymers as catalyst for mild oxidation of mercaptans
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Current work is devoted to covalent immobilization of sulfonated derivatives of cobalt phthalocyanines "Merox catalysts" on the surfaces of polypropylene and polyethylene terephthalate. Their catalytic activity in reaction of mild oxidation of sulfur compounds to disulfides with oxygen of the air was studied. Anchoring of the catalyst on this polymer prevents its leaching and promotes its efficient recovering and recycling without significant loss of catalytic activity.
- Vashurin, Artur,Kuzmin, Ilya,Razumov, Mikhail,Pukhovskaya, Svetlana,Golubchikov, Oleg,Voronina, Alena,Shaposhnikov, Gennady,Koifman, Oscar
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- Preparation and characterization of organically modified MCM-48 as heterogonous catalyst for oxidation of sulfides and thiols
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MCM-48 mesoporous synthesized and grafted with aminopropyl triethoxysilane (APTES) and subsequently reacted by isatin to obtain the imine of MCM-48. Addition of ZrOCl2.8H2O, leading to form the complex of Zr(IV)/isatin-MCM-48 as new Schiff base complex of zirconium(IV)-modified-MCM-48. The synthesized catalyst was characterized by XRD, TGA, FT-IR and BET. The resulting catalyst was efficient for selective oxidation of sulfides to sulfoxides and oxidation of thiols to disulfides with hydrogen peroxide. In this method isolation and reusability of catalyst have been investigated.
- Hajjami, Maryam,Yousofvand, Zakieh
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- Activation Parameters for Thiolate-Disulfide Interchange Reactions in Aqueous Solution
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We have measured activation parameters for thiolate-disulfide interchange reactions in water.Two disulfides were examined (Ellman's reagent and oxidized glutathione) and three thiols (2-mercaptoethanol, 1,3-dithiopropan-2-ol, and 1,4-dithiothreitol).These values are consistent with the interpretation of this reaction as an uncomplicated SN2 reaction of thiolate anion on the disulfide bond.
- Whitesides, George M.,Houk, Janette,Patterson, Mark A. K.
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- Thiol-dependent DNA cleavage by 3H-1,2-benzodithiol-3-one 1,1-dioxide
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Hydrodisulfides (RSSH) have previously been implicated as key intermediates in thiol-triggered oxidative DNA damage by the antitumor agent leinamycin. In an effort to better understand DNA damage by RSSH and to expand on the number and type of chemical systems that produce this reactive intermediate, the ability of 3H-1,2-benzodithiol-3-one 1,1-dioxide (11) to serve as a thio-dependent DNA cleaving agent has been investigated. The findings reported here indicate that reaction of 11 with thiols results in release of RSSH and subsequent oxidative DNA strand cleavage. (C) 2000 Elsevier Science Ltd. All rights reserved.
- Breydo, Leonid,Gates, Kent S.
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- Oxo-vanadium(IV) unsymmetrical Schiff base complex immobilized on γ-Fe2O3 nanoparticles: A novel and magnetically recoverable nanocatalyst for selective oxidation of sulfides and oxidative coupling of thiols
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In this research, an unsymmetrical salen-type oxo-vanadium(IV) complex, [VO(salenac-OH)] (salenac-OH = [9-(2′,4′-dihydroxyphenyl)-5,8-diaza-4-methylnona-2,4,8-trienato](-2)), was synthesized and covalently immobilized on the surface of magnetic γ-Fe2
- Mahdian, Abolfazl,Ardakani, Mehdi Hatefi,Heydari-Bafrooei, Esmaeil,Saeednia, Samira
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- Kinetics and mechanism of oxygen atom abstraction from a dioxo-rhenium(VII) complex
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The kinetics of reaction between triarylphosphanes and two newly prepared dioxorhenium(VII) compounds has been evaluated. The compounds are MeReVII(O)2( O,S ) in which O,S represents an alkoxo, thiolato chelating ligand. With MeReO3, ligands derived from 1-mercaptoethanol and 1-mercapto-2-propanol form MeRe(O)2(met), 2, and MeRe(O)2(m2p), 3. These compounds persist in chloroform solution for several hours at room temperature and for 2-3 weeks at -22°C, particularly when water is carefully excluded. They were obtained as red oils with clean 1H NMR spectra, but attempts to obtain pure, crystalline products were not successful because one decomposition pathway shows a kinetic order >1. The fastest reaction occurs between P(p-MeOC6H4)3 and 2; k298 = 215(7) L mol-1 s-1 in chloroform at 25(1)°C. The other rate constants follow a Hammett correlation against 3σ, with ρ = -0.69(7). This study relates to oxygen atom transfer reactions catalyzed by MeReO(mtp)PPh3, 1, in which MeRe(O)2(mtp), 4, is a postulated intermediate that does not build up to a measurable concentration during the catalytic cycle. Compound 2 does not react with MeSTol, but MeS(O)Tol was formed when tert-butyl hydroperoxide was added. This suggests that equilibrium lies to the left in this reaction, 2 + MeSTol + L = MeReO(met)L + MeS(O)Tol, and is drawn to the right by a reaction between MeReO(met)L and the hydroperoxide. Triphenyl arsane does not react with 2, but thermodynamic versus kinetic barriers were not resolved.
- Dixon, JaNeille,Espenson, James H.
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- Functionalized tellurium(II) thiolates: Tellurium bis(2-hydroxyethanethiolate) hydrate, the first H2O - Te(II) complex
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Photochemically labile Te(CH2CH2OH)2 is the first tellurium(II) thiolate with functionalized side chains. Its H2O complex, Te(CH2CH2OH)2·H2O (see structure), is stabil
- Fleischer, Holger,Schollmeyer, Dieter
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- Silica sulfuric acid/NaNO2 as a novel heterogeneous system for production of thionitrites and disulfides under mild conditions
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Neat chlorosulfonic acid reacts with silica gel to give silica sulfuric acid in which sulfuric acid is immobilized on the surface of silica gel via covalent bond. Thiols can be readily converted to their corresponding thionitrites with a combination of silica sulfuric acid, wet SiO2 and sodium nitrite in dichloromethane at room temperature. Disulfides result from the homolytic cleavage of the sulfur-nitrogen bond of the unstable thionitrites and subsequent coupling of the resultant thiyl radicals.
- Zolfigol, Mohammad Ali
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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
- Molaei, Somayeh,Ghadermazi, Mohammad,Moeini, Nazanin
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p. 771 - 793
(2021/12/02)
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- One-Pot Construction of Sulfur-Rich Thermoplastic Elastomers Enabled by Metal-Free Self-Switchable Catalysis and Air-Assisted Coupling
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Construction of well-defined sulfur-rich macromolecules in a facile manner is an interesting but challenging topic. Herein, we disclose how to readily construct well-defined triblock sulfur-rich thermoplastic elastomers via a self-switchable isothiocyanate/episulfide copolymerization and air-assisted oxidative coupling strategy. During self-switchable polymerization, alternating copolymerization of isothiocyanate and episulfide occurs initially due to the lower energy barrier for isothiocyanate insertion with respect to successive episulfide ring-opening. After exhaustion of isothiocyanate, ring-opening polymerization of episulfide begins, providing diblock polymers. Subsequent exposure of the reaction to air leads to a transformation of diblock copolymers into triblock thermoplastic elastomers. This protocol can be extended to diverse isothiocyanates and episulfides, allowing fine-tuning of the performance of the produced sulfur-rich thermoplastic elastomers.
- Wu, Guang-Peng,Xie, Rui,Yang, Guan-Wen,Zhu, Xiao-Feng
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supporting information
(2021/12/27)
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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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- 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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- Photochemical metal-free aerobic oxidation of thiols to disulfides
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Thiol oxidation to disulfides is an area of great importance in organic synthesis, both for synthetic and biological purposes. Herein, we report a mild, inexpensive and green photochemical approach for the synthesis of both symmetrical and non-symmetrical disulfides, using metal-free and environmentally friendly conditions. Utilizing phenylglyoxylic acid as the photoinitiator, common household bulbs as the light source and a simple inorganic salt as the additive, a versatile oxidation of thiols leading to products in excellent yields is described. This journal is
- Spiliopoulou, Nikoleta,Kokotos, Christoforos G.
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supporting information
p. 546 - 551
(2021/01/28)
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- A green disulfide synthesis method
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The present invention discloses a green disulfide synthesis method, belonging to the field of green chemical and organic synthesis technology. Under room temperature, open, neutral conditions, rapid preparation of parent nuclei is alkanes, olefins, aromatic hydrocarbons, oxazole, thiazole, pyrazole, imidazole, etc. and their derivatives of symmetrical disulfide, the catalyst is MBrx(M is Fe2+,Fe3+,Ce3+, etc., x is 2-3), the only oxidant isH2O2. The present invention is reacted by using commercially available and low-cost reagents (e.g., FeBr2,CeBr3 andH2O2,etc.) and common organic solvents, the steps are concise, the operation is convenient, the reaction is rapid, the reaction conditions are mild, the room temperature is open, and no further purification can be obtained pure disulfide, more advantageous than all previous methods, is expected to be in organic synthesis, medicine, Pesticides and electronics and other industries are widely used.
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Paragraph 0049-0051
(2022/01/08)
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- Dihydric alcohol containing disulfide bond as well as preparation method and application thereof
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The invention relates to the technical field of dihydric alcohol, in particular to dihydric alcohol containing disulfide bonds as well as a preparation method and application thereof. The structure ofthe disulfide bond-containing dihydric alcohol is shown as a formula (1) as the specification; the preparation raw materials of the disulfide bond-containing dihydric alcohol comprise a compound shown as a formula (2) and peroxide, wherein the formula (2) is shown as the specification; in the process of preparing the dihydric alcohol containing the disulfide bond, cheap raw materials are adopted,no catalyst is used, a one-pot reaction is adopted, and the method is simple in process, convenient to operate and easy to implement; a micro-channel mixing reactor is adopted, so that excessive polyether byproducts are prevented from being generated, and the purity is improved; meanwhile, the problem of product purity caused by constructing disulfide bonds by using polysulfide is avoided. The disulfide bond-containing dihydric alcohol can be applied to the fields of polyester, polyurethane and other materials, and is used for improving the performance of the materials.
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Paragraph 0056; 0063; 0074-0109
(2021/03/31)
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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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p. 642 - 655
(2020/08/19)
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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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- Preparation and characterization of Cu (II) Schiff base complex functionalized boehmite nanoparticles and its application as an effective catalyst for oxidation of sulfides and thiols
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The synthesis, characterization, and evaluation of a Schiff base Cu (II) complex functionalized boehmite nanoparticles (Cu-complex-boehmite) as a new catalyst for oxidation of sulfides and thiols in the presence of hydrogen peroxide with complete selectivity and high conversion under solvent-free and mild reaction conditions were reported. Characterization of the catalyst was performed with various physicochemical methods. This effective catalyst was evaluated in terms of activity and reusability. It indicated high catalytic activity, good recoverability and reusability, and supplied the corresponding products in high yields and short reaction times. In addition, it shows notable advantages such as simplicity of operation, heterogeneous nature, easy work up, and it could be used at least eight times with no significant loss of its activity.
- Khodaei, Mohammad Mehdi,Alizadeh, Abdolhamid,Afshar Hezarkhani, Hadis
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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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- Bicyclobutane carboxylic amide as a cysteine-directed strained electrophile for selective targeting of proteins
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Expanding the repertoire of electrophiles with unique reactivity features would facilitate the development of covalent inhibitors with desirable reactivity profiles. We herein introduce bicyclo[1.1.0]butane (BCB) carboxylic amide as a new class of thiol-reactive electrophiles for selective and irreversible inhibition of targeted proteins. We first streamlined the synthetic routes to generate a variety of BCB amides. The strain-driven nucleophilic addition to BCB amides proceeded chemoselectively with cysteine thiols under neutral aqueous conditions, the rate of which was significantly slower than that of acrylamide. This reactivity profile of BCB amide was successfully exploited to develop covalent ligands targeting Bruton's tyrosine kinase (BTK). By tuning BCB amide reactivity and optimizing its disposition on the ligand, we obtained a selective covalent inhibitor of BTK. The in-gel activitybased protein profiling and mass spectrometry-based chemical proteomics revealed that the selected BCB amide had a higher target selectivity for BTK in human cells than did a Michael acceptor probe. Further chemical proteomic study revealed that BTK probes bearing different classes of electrophiles exhibited distinct off-target profiles. This result suggests that incorporation of BCB amide as a cysteine-directed electrophile could expand the capability to develop covalent inhibitors with the desired proteome reactivity profile.
- Shindo, Naoya,Ojida, Akio,Tokunaga, Keisuke,Sato, Mami,Kuwata, Keiko,Miura, Chizuru,Fuchida, Hirokazu,Matsunaga, Naoya,Koyanagi, Satoru,Ohdo, Shigehiro
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supporting information
p. 18522 - 18531
(2020/11/02)
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- Insights into the Mechanism of Thiol-Triggered COS/H2S Release from N-Dithiasuccinoyl Amines
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The hydrolysis of carbonyl sulfide (COS) to form H2S by carbonic anhydrase has been demonstrated to be a viable strategy to deliver H2S in a biological system. Herein, we describe N-dithiasuccinoyl amines as thiol-triggered COS/H2S donors. Notably, thiol species especially GSH and homocysteine can trigger the release of both COS and H2S directly from several specific analogues via an unexpected mechanism. Importantly, two representative analogues Dts-1 and Dts-5 show intracellular H2S release, and Dts-1 imparts potent anti-inflammatory effects in LPS-challenged microglia cells. In conclusion, N-dithiasuccinoyl amine could serve as promising COS/H2S donors for either H2S biological studies or H2S-based therapeutics development.
- Zhou, Shengchao,Mou, Yujie,Liu, Miao,Du, Qian,Ali, Basharat,Ramprasad, Jurupula,Qiao, Chunhua,Hu, Li-Fang,Ji, Xingyue
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p. 8352 - 8359
(2020/09/07)
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- Oxidative Formation of Disulfide Bonds by a Chemiluminescent 1,2-Dioxetane under Mild Conditions
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The oxidation of alkyl thiols to disulfides has been achieved under mild conditions using a chemiluminescent 1,2-dioxetane as a stoichiometric oxidant. Besides the mild and biocompatible reaction conditions, this approach offers the possibility to monitor the presence of thiols through oxidation and chemiluminescence of the remaining dioxetane.
- Sauer, Caroline S.,K?ckenberger, Johannes,Heinrich, Markus R.
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supporting information
p. 9331 - 9338
(2020/08/14)
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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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- 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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- 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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- 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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p. 305 - 311
(2019/08/12)
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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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- 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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- Preparation and application of polymerizable disulfide capable of reducing volume shrinkage
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The invention relates to preparation and application of polymerizable disulfide capable of reducing volume shrinkage. The synthesis comprises the following steps: adding aliphatic sulfhydrate with reactive hydrogen and sodium iodide into a reactor, adding hydrogen peroxide dropwise under the condition of magnetic stirring and reacting to obtain a product A; and putting the product A and organic alkali into a reaction bottle and adding an acyl chloride compound dropwise under the action of magnetic stirring to obtain the polymerizable disulfide. The preparation and the application of the polymerizable disulfide capable of reducing volume shrinkage have the following beneficial effects: (1) the polymerizable disulfide can obviously reduce the volume shrinkage in the photopolymerization process and provides a new method for reducing volume shrinkage; and (2) the polymerizable disulfide can take part in photopolymerization and also can initiate photopolymerization.
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Paragraph 0023
(2018/06/28)
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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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- 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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- 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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- 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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- 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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p. 1834 - 1847
(2018/05/15)
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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 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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- 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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-
- An Organodiselenide with Dual Mimic Function of Sulfhydryl Oxidases and Glutathione Peroxidases: Aerial Oxidation of Organothiols to Organodisulfides
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A novel organodiselenide, which mimics sulfhydryl oxidases and glutathione peroxidase (GPx) enzymes for oxidation of thiols by oxygen and hydrogen peroxide, respectively, into disulfides has been presented. The developed catalyst oxidizes an array of organothiols into respective disulfides in practical yields by using aerial O2 to avoid any reagents/additives, base, and light source. The synthesized diselenide also catalyzes the reduction of hydrogen peroxide into water by following the GPx enzymatic catalytic cycle with a reduction rate of 49.65 ± 3.7 μM·min-1.
- Rathore, Vandana,Upadhyay, Aditya,Kumar, Sangit
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supporting information
p. 6274 - 6278
(2018/10/05)
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- Unsymmetrical Disulfide Synthesis through Photoredox Catalysis
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A facile and eco-friendly visible light-mediated synthesis of symmetrical and unsymmetrical disulfides using tris[2-phenylpyridinato-C2,N]iridium(III) under additive and oxidant free conditions has been disclosed. The developed method is very mild, several functional group tolerant and highly atom economical requiring extremely low amount of catalyst loading (0.5 mol%). (Figure presented.).
- Dethe, Dattatraya H.,Srivastava, Aparna,Dherange, Balu D.,Kumar, B. Vijay
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supporting information
p. 3020 - 3025
(2018/08/23)
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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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p. 1363 - 1380
(2017/10/30)
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- Highly Chemoselective Deprotection of the 2,2,2-Trichloroethoxycarbonyl (Troc) Protecting Group
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Nonreducing, pH-neutral conditions for the selective cleavage of the 2,2,2-trichloroethoxycarbonyl (Troc) protecting group are reported. Using trimethyltin hydroxide in 1,2-dichloroethane, Troc-protected alcohols, thiols, and amines can be selectively unmasked in the presence of various functionalities that are incompatible with the reducing conditions traditionally used to remove the Troc group. This mild deprotection protocol tolerates a variety of other hydrolytically sensitive and acid/base-sensitive moieties as well.
- Trost, Barry M.,Kalnmals, Christopher A.,Tracy, Jacob S.,Bai, Wen-Ju
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supporting information
p. 8043 - 8046
(2019/01/04)
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- Dialkyl Dicyanofumarates as Oxidizing Reagents for the Conversion of Thiols into Disulfides and Selenols into Diselenides
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Aliphatic and aromatic thiols react smoothly with dialkyl dicyanofumarates in CH2Cl2 at room temperature to give the corresponding disulfides in excellent yields. Aliphatic 1,2-, 1,3-, and 1,4-dithiols afford cyclic disulfides. Analogous reaction courses were observed for selenols, and the required diselenides also formed in nearly quantitative yields. In all of the reactions, dialkyl dicyanosuccinates formed as 1:1 mixtures of diastereoisomers as the only other product. Cysteamine (2-mercaptoethylamine) behaved differently; the Michael addition of the primary amine group led to the complete consumption of the dicyanofumarate, and the formation of the disulfide containing an enamine moiety occurred without the formation of dicyanosuccinate.
- Mlostoń, Grzegorz,Capperucci, Antonella,Tanini, Damiano,Hamera-Fa?dyga, Ró?a,Heimgartner, Heinz
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p. 6831 - 6839
(2017/09/11)
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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 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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- Method for catalytic synthesis of dithio diethylene glycol from taurine
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The invention discloses a method for catalytic synthesis of dithio diethylene glycol from taurine. According to the method, firstly, taurine is added into a reaction vessel; deionized water is added for full dissolution; after the dissolution, raw materials of mercaptoethanol are added; then, an oxidizing agent of hydrogen peroxide is dropwise added for reaction; after the reaction is completed, reaction liquid is extracted; the reaction liquid obtained after the extraction is sequentially washed, dried and filtered; after the filtering, the obtained filtering liquid is subjected to pressure reduction to remove solvents used during the extraction through steaming; finally, the product of dithio diethylene glycol liquid is obtained. The small-molecule catalyst of taurine is used for preparing the dithio diethylene glycol through catalytic synthesis; the preparation method is simple; the recovery is easy; the dithio diethylene glycol is synthesized under the condition without using any organic solvents. When the method is used for preparing the dithio diethylene glycol, the production cost is low; the reaction conditions are mild; after the reaction, the product can be easily separated; the energy is saved and the consumption is reduced.
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Paragraph 0066; 0067; 0068; 0069; 0070; 0071-0101
(2017/11/30)
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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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- Method for synthesizing dithio diethylene glycol by catalyzing water-soluble amino acids
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The invention discloses a method for synthesizing dithio diethylene glycol by catalyzing water-soluble amino acids. The method comprises the following steps: firstly, adding the water-soluble amino acids into a reactor, adding deionized water for sufficiently dissolving, then adding a raw material mercaptoethanol and dropwise adding an oxidant hydrogen peroxide for reacting; secondly, after the reaction is ended, extracting an obtained reacting solution, sequentially washing, drying and filtering the reaction solution obtained by extracting, carrying out reduced pressure distillation on filtrate obtained by filtering, and removing a solvent adopted by the extraction; finally, obtaining a product dithio diethylene glycol liquid. The preparation method disclosed by the invention is simple in operation and easy to recover; in addition, the dithio diethylene glycol is synthesized under the condition of no organic solvent and is prepared by adopting the technical scheme provided by the invention; the preparation method has the advantages of low production cost, mild reaction conditions, energy saving and consumption reduction; reacted products are not easy to separate.
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Paragraph 0066-0101
(2018/01/04)
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- Dynamic covalent chemistry in aqueous solution by photoinduced radical disulfide metathesis
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Photoinduced radical disulfide metathesis (PRDM) is a dynamic covalent reaction that requires UV light to induce the homolytic cleavage of the disulfide bond, thus offering the opportunity to construct dynamic covalent systems that are dormant and can be photo-Activated on demand. In this work, we showcase how PRDM can be utilized in aqueous solution and demonstrate its potential by generating a UV responsive hydrogel from an asymmetrical disulfide precursor.
- Klepel, Florian,Ravoo, Bart Jan
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supporting information
p. 3840 - 3842
(2017/07/11)
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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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- 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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- 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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- 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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p. 56458 - 56466
(2016/07/06)
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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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- 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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- 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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