- 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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- Cu attached functionalized mesoporous MCM-41: a novel heterogeneous nanocatalyst for eco-friendly one-step thioether formation reaction and synthesis of 5-substituted 1H-tetrazoles
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In the current study, a mesoporous copper-attached functionalized MCM-41 with the DL-Pyroglutamic acid framework has been produced through a post-synthetic method. The MCM-41 functionalization technique has been used to synthesize this novel heterogeneous catalyst. The material has been identified fully using XRD, FT-IR, BET, EDX, elemental mapping, SEM, and TGA. This catalyst displays high catalytic performance in the one-step thioether formation (C–S) reaction and synthesis of 5-substituted 1H-tetrazoles. The main aspects of this economical copper-catalyzed procedure are green synthesis, slighter experimental conditions, and less reaction time with no additives. Further benefits comprise experimental comfort of handling, secure replacement to dangerous, damaging, and poisoning regular Lewis’s acid catalysts, and reusability with constant catalytic performance. Graphic abstract: [Figure not available: see fulltext.]
- Molaei, Somayeh,Ghadermazi, Mohammad
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p. 4557 - 4581
(2021/07/28)
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- Heterogeneously Ni-Pd nanoparticle-catalyzed base-free formal C-S bond metathesis of thiols
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This study rationally designed a heterogeneously catalyzed system (i.e., using Ni-Pd alloy nanoparticles supported on hydroxyapatite (Ni-Pd/HAP) under an H2atmosphere) achieving an efficient base-free formal C-S bond metathesis of various thiolsviasuppression of the Ni catalysis deactivation.
- Mitamura, Kanju,Yatabe, Takafumi,Yamamoto, Kidai,Yabe, Tomohiro,Suzuki, Kosuke,Yamaguchi, Kazuya
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supporting information
p. 3749 - 3752
(2021/04/21)
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- Solid-State C-S Coupling in Nickel Organochalcogenide Frameworks as a Route to Hierarchical Structure Transfer to Binary Nanomaterials
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In this work, the transfer of the flexible and easily tunable hierarchical structure of nickel organochalcogenides to different binary Ni-based nanomaterials via selective coupling of organic units was developed. We suggested the use of substituted aryl groups in organosulfur ligands (SAr) as traceless structure-inducing units to prepare nanostructured materials. At the first step, it was shown that the slight variation of the type of SAr units and synthetic procedures allowed us to obtain nickel thiolates [Ni(SAr)2]n with diverse morphologies after a self-assembly process in solution. This feature opened the way for the synthesis of different nanomaterials from a single type of precursor using the phenomenon of direct transfer of morphology. This study revealed that various nickel thiolates undergo selective C-S coupling under high-temperature conditions with the formation of highly demanding nanostructured NiS particles and corresponding diaryl sulfides. The in situ oxidation of the formed nickel sulfide in the case of reaction in an air atmosphere provided another type of valuable nanomaterial, nickel oxide. The high selectivity of the transformation allowed the preservation of the initial organochalcogenide morphologies in the resulting products.
- Ananikov, Valentine P.,Degtyareva, Evgeniya S.,Galushko, Alexey S.,Kashin, Alexey S.
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- Magnetically recoverable ferromagnetic 3D hierarchical core-shell Fe3O4@NiO/Co3O4 microspheres as an efficient and ligand-free catalyst for C–S bond formation in poly (ethylene glycol)
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A simple and efficient protocol for the synthesis of diaryl thioethers from the reaction of thiourea with a wide variety of aryl halides, including aryl iodides, aryl bromides and aryl chlorides in the presence of 3D hierarchical core-shell Fe3O4@NiO/Co3O4 microspheres has been described. This reaction enables the one-pot synthesis of diaryl thioethers in good to high yields using a non-toxic and magnetically separable catalyst in PEG-400 as an eco-friendly, safe, inexpensive and thermally stable solvent. Magnetic separation and reusability of catalyst for eight times without any significant loss of activity, the use of a commercially available, eco-friendly, cheap and chemically stable sulfur transfer agent and solvent, operational simplicity, environmentally benign, easier work-up procedure and cost efficiency make this method a promising candidate for potential applications in some organic reactions. The catalytic activity of Fe3O4@NiO/Co3O4 as a novel and inexpensive catalyst was investigated in the C-S cross coupling reaction.
- Vatandoust Namanloo, Ahad,Akhlaghinia, Batool,Mohammadinezhad, Arezou
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p. 446 - 461
(2020/05/13)
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- Room temperature nickel-catalyzed cross-coupling of aryl-boronic acids with thiophenols: Synthesis of diarylsulfides
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A NiCl2/2,2′-bipyridine-catalyzed cross-coupling of thiophenols with arylboronic acids has been developed for the synthesis of symmetric and unsymmetric diarylsulfides at room temperature and in air. This methodology is reliable and offers a mild and easy to operate process for the synthesis of arylthioethers, which are essential compounds with applications in the pharmaceutical and agricultural industries. This method avoids the use of expensive transition metals, such as Pd, Ir or Rh, sophisticated ligands and elevated temperatures. It also has a wide substrate scope (55 examples) and provides products in good to excellent yields (72-93%).
- Bhowmik, Amit,Fernandes, Rodney A.,Yadav, Mahesh
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p. 2447 - 2458
(2020/04/15)
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- CuI anchored onto mesoporous SBA-16 functionalized by aminated 3-glycidyloxypropyltrimethoxysilane with thiosemicarbazide (SBA-16/GPTMS-TSC-CuI): A heterogeneous mesostructured catalyst for: S -arylation reaction under solvent-free conditions
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Herein, we report the novel synthesis of CuI anchored onto a cage-like mesoporous material (SBA-16), which was successfully functionalized by aminated 3-glycidyloxypropyltrimethoxysilane with thiosemicarbazide (SBA-16/GPTMS-TSC-CuI) into an efficient and highly recyclable heterogeneous catalyst. The as-synthesized mesostructured catalyst (SBA-16/GPTMS-TSC-CuI) was comprehensively characterized by different techniques, namely, FT-IR, FIR, SAXRD, XRD, XPS, BET, TEM, FE-SEM, EDX, EDX mapping, TGA, ICP-OES, and CHNS analyses. SBA-16 with a unique "super-cage" structure efficiently controlled the formation of dispersed organic and metal species in the mesoporous channels. These confined nanoparticles with a narrow particle size distribution (3-7 nm) exhibited excellent catalytic activity in the S-arylation reaction without necessitating the use of toxic solvents and/or expensive metal catalysts. Interestingly, the mesoporous catalyst was extremely stable under the reaction conditions and could be easily separated by a simple filtration process and reused for at least seven recycle runs (without any appreciable loss in catalytic activity). Due to the inimitable structure of the abovementioned mesostructured catalyst, the C-S coupling products of aryl halides with S8/thiourea under solvent-free conditions were obtained in good to excellent yields in remarkably reduced reaction times in comparison to those reported in earlier studies.
- Ghodsinia, Sara S.E.,Akhlaghinia, Batool
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supporting information
p. 3029 - 3049
(2019/06/17)
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- Immobilization of Pd(0) complex on the surface of SBA-15: A reusable catalyst for the synthesis of 5-substituted tetrazoles, sulfides and sulfoxides
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A simple and efficient method for the synthesis of 5-substituted tetrazoles, sulfides and sulfoxides in the presence of Pd(0) complex immobilized on mesoporous SBA-15 as an efficient, recoverable and thermally stable mesostructure has been reported. Also, the prepared mesostructure was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray mapping, energy-dispersive X-ray spectroscopy, N2 adsorption and desorption, inductively coupled plasma optical emission spectroscopy and thermal gravimetric analysis. Then, this mesostructured catalyst was applied in the synthesis of 5-substituted tetrazoles, sulfides and sulfoxides. The approach described here offers advantages such as short reaction times, high yield, purity yields, simple and eco- friendly, easy work-up. More importantly, this nanohybrid robust catalyst did not undergo metal leaching and applied several times without any decrease in catalytic activity.
- Tamoradi, Taiebeh,Ghorbani-Choghamarani, Arash,Ghadermazi, Mohammad
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p. 374 - 380
(2018/11/01)
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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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p. 10343 - 10351
(2019/07/09)
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- Core–shell nanostructure (Fe3O4?MCM-41?Cu-P2C) as a highly efficient and recoverable nanocatalyst for the synthesis of polyhydroquinoline, 5-substituted 1H-tetrazoles and sulfides
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Fe3O4 magnetic nanoparticles were used as a core for Cu(II) Schiff base complex functionalized mesoporous MCM-41 shell to provide a core–shell nanostructure (Fe3O4?MCM-41?Cu-P2C). A simple, environmentally friendly, inexpensive, green reaction conditions and efficient procedure for the synthesis of polyhydroquinoline, 5-substituted 1H-tetrazoles and sulfides derivatives using this core–shell nanostructure as an efficient, novel and recoverable nanocatalyst has been described. Fe3O4?MCM-41?Cu-P2C is stable, cost-effective, heterogeneous, easy to handle and recoverable nanocatalyst and can be reused for several consecutive runs without a significant loss of catalytic activity. The catalyst was characterized by fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), powder X-ray diffractometer (XRD), scanning electron microscopy (SEM), atomic absorption spectroscopy (AAS), Brunauer–Emmett–Teller (BET) and vibrating sample magnetometer (VSM) techniques.
- Nikoorazm, Mohsen,Erfani, Zahra
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- Synthesis method of thioether compounds
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The invention discloses a synthesis method of thioether compounds. The method comprises steps as follows: phosphorus trichloride and a solvent with uniformly distributed sulfoxide compounds are mixeduniformly, after mixing, the mixture is subjected to a reaction at the temperature of 20-25 DEG C for 0.5-6 h, and the thioether compounds are obtained, wherein the solvent is acetonitrile. Compared with the prior art, the synthesis method has the advantages that raw materials are cheap and easy to obtain, a reducer is cheap and easy to obtain and store, and a series of thioether compounds can beobtained.
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Paragraph 0162-0166
(2019/08/02)
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- Deoxygenation of sulphoxides to sulphides with trichlorophosphane
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An efficient route to deoxygenation of sulphoxides to sulphides with PCl3 under mild reaction condition was developed. PCl3 was used as a reducing agent for the first time to convert sulphoxides to sulphides. The mild conditions, use of cheap and readily available reagent, and broad substrate scope render it a useful strategy for preparing sulphides.
- Zhao, Xia,Zheng, Xiancai,Yang, Bo,Sheng, Jianqiao,Lu, Kui
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p. 1200 - 1204
(2018/02/21)
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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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- The first report on the preparation of peptide nanofibers decorated with zirconium oxide nanoparticles applied as versatile catalyst for the amination of aryl halides and synthesis of biaryl and symmetrical sulfides
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We have reported the preparation of peptide nanofibers decorated with zirconium oxide nanoparticles for the first time as a novel, non-toxic, inexpensive and recyclable catalyst for the amination of aryl halides and synthesis of biaryl and symmetrical sulfides (via reaction of aryl halides with S8 or 2-thiobarbituric acid as sulfur transfer reagents). The structure of the catalyst was studied by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), atomic absorption spectroscopy (AAS), UV-visible absorption and fluorescence spectroscopy.
- Ghorbani-Choghamarani, Arash,Taherinia, Zahra
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p. 9414 - 9423
(2017/08/29)
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- Anchoring of Cu(II)–vanillin Schiff base complex on MCM-41: A highly efficient and recyclable catalyst for synthesis of sulfides and 5-substituted 1H–tetrazoles and oxidation of sulfides to sulfoxides
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A copper(II)–vanillin complex was immobilized onto MCM-41 nanostructure and was used as an inexpensive, non-toxic and heterogeneous catalyst in the synthesis of symmetric aryl sulfides by the cross-coupling of aromatic halides with S8 as an effective sulfur source, in the oxidation of sulfides to sulfoxides using 30% H2O2 as a green oxidant and in the synthesis of 5-substituted 1H–tetrazoles from a smooth (3?+?2) cycloaddition of organic nitriles with sodium azide (NaN3). The products were obtained in good to excellent yields. This catalyst could be reused several times without loss of activity. Characterization of the catalyst was performed using Fourier transform infrared, energy-dispersive X-ray and atomic absorption spectroscopies, X-ray diffraction, thermogravimetric analysis, and scanning and transmission electron microscopies.
- Khanmoradi, Maryam,Nikoorazm, Mohsen,Ghorbani-Choghamarani, Arash
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- Synthesis of sulfides via reaction of aryl/alkyl halides with S8 as a sulfur-transfer reagent catalyzed by Fe3O4-magnetic-nanoparticles-supported L-Histidine-Ni(II)
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One-pot synthesis of symmetrical diaryl/alkyl sulfides in high yields from the reaction between aryl/alkyl halides and S8 can be carried out in a short period, using Fe3O4@SiO2@His@Ni(II) as a reusable catalyst. The present approach offers the advantages of a clean reaction, simple methodology and high efficiency, and avoids the use of a toxic catalyst.
- Azadi, Gouhar,Taherinia, Zahra,Naghipour, Ali,Ghorbani-Choghamarani, Arash
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p. 303 - 313
(2017/05/04)
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- Synthesis of peptide nanofibers decorated with palladium nanoparticles and its application as an efficient catalyst for the synthesis of sulfides: Via reaction of aryl halides with thiourea or 2-mercaptobenzothiazole
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In this work supported Pd nanoparticles on a peptide nanofiber (PdNP-PNF) have been prepared via fabrication of self-assembled woven nanofiber from peptide, subsequently immobilization of palladium nanoparticles on this nanostructural compound. To obtain self-assembled woven nanofiber, we designed and synthesized a peptide using arginine as building block. The C-terminus of amino acid was protected as ethylester. Coupling was mediated by dicyclohexylecarbodiimide-1-hydroxybenzotriazole (DCC-HOBT). TEM, SEM, XRD, ICP and FT-IR techniques were employed to characterize prepared nanofiber materials. In this work, the effect of phosphate buffer solutions pH 8 and pH 11 (isoelectric point of arginine amino acid) on the structure of peptide nanofiber was investigated. Supported Pd nanoparticles on the peptide nanofiber (PdNP-PNF) were applied for the C-S coupling reaction using two different sulfur transfer reagents (thiourea and 2-mercaptobenzothiazole).
- Ghorbani-Choghamarani, Arash,Taherinia, Zahra
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p. 59410 - 59421
(2016/07/06)
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- A very useful and mild method for the deoxygenation of sulfoxide to sulfide with silica bromide as heterogeneous promoter
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Silica bromide (SB) as heterogeneous reagent and promoter is prepared from reaction of silica gel with PBr3 as a non-hydroscopic, filterable, cheap, and stable yellowish powder that can be stored for months. The results show that the SB is suitable and efficient reagent for deoxygenation of sulfoxides to the corresponding sulfides under mild conditions at room temperature. The easy availability of this reagent makes this simple procedure attractive and a practical alternative to the existing methods.
- Mohanazadeh, Farajollah,Veisi, Hojat,Sedrpoushan, Alireza,Zolfigol, Mohammad Ali,Golmohammad, Fereshteh,Hemmati, Saba,Hashemi, Majid
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- Investigations on the Lewis-acids-catalysed electrophilic aromatic substitution reactions of thionyl chloride and selenyl chloride, the substituent effects, and the reaction mechanisms
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The previously established aluminium-chloride-(AlCl3)-catalysed electrophilic aromatic substitution (EAS) of benzene (PhH) with thionyl chloride (SOCl2) has been extended to toluene (PhCH3), chlorobenzene (PhCl), and phenol (PhOH). -CH3 was found to be mainly a para-director with a minor ortho-directing effect on the EAS reactions giving diaryl sulfoxides (Ar2SO). -Cl was found to be exclusively a para-director for formation of Ar2SO. All the -CH3, -Cl, and -OH groups were shown to be exclusive para-directors for formation of diaryl sulfides (Ar2S) from the EAS reactions. Although the reactions of PhH and PhCH3 with SOCl2 in the presence of AlCl 3 gave the major Ar2SO and minor Ar2S at ambient temperature, the phenol (PhOH) reaction was shown to give only the reduced sulfide (p-HOC6H4)2S with no sulfoxide (p-HOC6H4)2SO formed. The mixed diaryl sulfoxides ArSOAr′ (Ar, Ar′=C6H5, p-CH 3C6H4; C6H5, o-CH 3C6H4; and C6H5, p-ClC6H4) were produced in the AlCl3-catalysed reactions of SOCl2 with molar 1:1 PhH-PhX mixtures (X=CH3 and Cl). Efforts to enhance the yield of S-aryl arenesulfonothioates ArSO 2SAr (Ar=Ph, p-CH3C6H4, and p-ClC6H4) from the AlCl3-catalysed EAS reactions of SOCl2 were made, showing that decreasing the molar ratios of ArH/SOCl2 or lowering the temperature resulted in an increase in the product yield. A detailed mechanism has been proposed to account for the formation of ArSO2SAr. The Lewis-acid-MCl3-(M=Al and Fe)-catalysed EAS reactions of PhH with selenyl chloride (SeOCl2) were demonstrated to give the reduced diphenyl selenide (Ph2Se) and diphenyl diselenide (PhSeSePh) via novel auto-redox processes in selenium of the key EAS intermediates.
- Sun, Xiaoping,Haas, David,McWilliams, Samantha,Smith, Benjamin,Leaptrot, Katrina
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p. 736 - 744
(2014/01/23)
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- Use of base control to provide high selectivity between diaryl thioether and diaryl disulfide for C-S coupling reactions of aryl halides and sulfur and a mechanistic study
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Previous studies have reported that S-arylation produces diaryl disulfide when the precursors include sulfur powder and aryl halide using CuI as the catalyst. However, our research has revealed that the use of different bases in the above S-arylation process results in the coproduction of diarylsulfane and diaryldisulfane. In addition, we have demonstrated that the ratio of the two products can be controlled by selecting the alkalinity of the bases. 1H NMR spectra showed that diaryldisulfane was the first product, which became the reagent in a reaction with aryl halide to form diarylsulfane through CuI catalysis. Various aryl halides were tested to enhance the selectivity between diarylsulfane and diaryldisulfane using various different bases, leading to the following principles. A weak base, such as metal carbonate or acetate, results in the production of only diaryldisulfane; a strong base, such as metal hydroxide, results in the production of both diaryldisulfane and diarylsulfane. According to DFT calculations, hydroxide ions, which were exchanged for iodide and bonded with Cu, affected Cu electrons more strongly to reduce diaryl disulfide.
- Chen, Hsing-Ying,Peng, Wei-Te,Lee, Ying-Hsien,Chang, Yu-Lun,Chen, Yen-Jen,Lai, Yi-Chun,Jheng, Nai-Yuan,Chen, Hsuan-Ying
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supporting information
p. 5514 - 5522
(2013/11/06)
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- Efficient copper(I)-catalyzed S-arylation of KSCN with aryl halides in PEG-400
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A simple and efficient protocol for CuI-catalyzed C-S bond formation of aryl halides with KSCN to symmetrical diaryl sulfides was reported in PEG-400 without any other additives. A variety of aryl halides were converted to the corresponding diaryl sulfides in good to excellent yields. The present procedure tolerated a variety of functional groups and the steric hindrance of ortho-substituents on aryl halides did not affect the outcome.
- Li, Xiaokang,Yuan, Tangjun,Chen, Junmin
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experimental part
p. 651 - 655
(2012/05/05)
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- Efficient copper-catalyzed double S-arylation of aryl halides with sodium sulfide in PEG-400
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An efficient copper-catalyzed double S-arylation of sodium sulfide with aryl halides in PEG-400 has been developed. With CuI as a catalyst and PEG-400 as a solvent, a range of electron-withdrawing or electron-donating aryl iodides and aryl bromides were found to be applicable to the environmentally benign system. The present procedure is mild and tolerant of a variety of functional groups and the steric hindrance of ortho-substituents on aryl halides did not affect the outcome of good to excellent yields. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.
- Chen, Junmin,Zhang, Yimin,Liu, Li,Yuan, Tangjun,Yi, Fei
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p. 1284 - 1290
(2012/11/07)
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- Polymer electrolyte and process for producing the same
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A polymer electrolyte having, in a main chain, a structural unit represented by the following formula (1):-[Ar1-(SO2-N-(X+)-SO2-Ar2)m-SO2-N-(X+)-SO2-Ar1-O]- wherein Ar1 and Ar2 independently represent a divalent aromatic groups, m represents an integer of 0 to 3, and X+ represents an ion selected from hydrogen ion, an alkali metal ion and ammonium ion, which is excellent in proton conductivity, thermal resistance and strength. The polymer electrolyte is soluble in solvents and has excellent film forming property and recycling efficiency.
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- Method for manufacturing bisphenol
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A method for manufacturing bisphenol by reacting phenols and ketones, characterized (1) in that an alkali metal compound and/or alkaline earth metal compound is added to bisphenol obtained by reacting a phenol and a ketone, and (2) in that the basicity of the bisphenol is adjusted so as to be equivalent to an amount of 1 × 10-8to 1 × 10-6moles of bisphenol as disodium salt with respect to 1 mole of bisphenol provides a bisphenol in which there is no residue of the organic catalysts ordinarily used in manufacturing bisphenol, so that byproducts are not produced during purification, allowing bisphenol with outstanding color tone, thermal resistance, etc., to be obtained.
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- Process for the purification of bisphenols and preparation of polycarbonates therefrom
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A phenol and a ketone are reacted to form bisphenol, and the liquid bisphenol obtained or a mixed solution of said solution and a phenol is filtered through a calcined metal filter to obtain bisphenol which makes it possible to efficiently obtain bisphenol which either does not contain fine particulate impurities or contains such impurities only in minute amounts, and a method for manufacturing polycarbonate using bisphenol obtained bythis method. The filtration grade of the calcined metal filter should be 1.0 μm or less. After filtering, the calcined metal filter can be backwashed or chemically washed and then reused. The bisphenol should preferably be bisphenol A.
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- Bisphosphine oxide monomers
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Bisphosphine oxide monomers and homologs thereof may be incorporated into polycarbonates in order to obtain a flame retardant polymer. More particularly, bis[2,5-(diphenylphosphine oxide)]-1,4-hydroquinone and homologs thereof may be used to prepare flame retardant polycarbonates that retain high glass transition temperature and high impact resistances.
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- Utilisations synthetiques d'une electrode soluble au soufre. III. Creation de l'enchainement C-S-C a partir d'ethers aromatiques et de phenols
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Use of a sacrificial sulfur electrode in electroorganic chemistry.III.Formation of the C-S-C bond from aromatic ethers and phenols.At a working potential of about +2.2 V (vs SCE) the carbon-sulfur electrode is a source of the electrogenerated cation S2+ in organic media.This electrophile can react with aromatic ethers and phenols to produce the corresponding monosulfides.This reaction may be regioselective. carbon-sulfur electrode / sacrificial electrode /sulfur cation / organic sulfide / electrophilic substitution
- Elothmani, Driss,Do, Quang Tho,Simonet, Jacques,Guillanton, Georges Le
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p. 779 - 788
(2007/10/02)
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- HIGH-TEMPERATURE ORGANIC SYNTHESIS. XLI. REACTIONS OF AROMATIC HALOGEN COMPOUNDS WITH HYDROGEN SULFIDE IN THE PRESENCE OF SULFUR
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The reactions of halogenoarenes containing a sufficiently mobile halogen atom with hydrogen sulfide in the presence of elemental sulfur at 90-230 deg C lead to the corresponding sulfides (with yields of up to 87percent).The disulfides, thiols, and arenes are formed at the same time.In the reactions of bromophenols with hydrogen sulfide in the presence of sulfur migration of the halogen atom is observed, and this leads to the formation of isomeric bis(hydroxyphenyl) sulfides and disulfides and 2,4-dibromophenol.It was established that the yield of the reaction products depends on the time, temperature, halogenophenol-sulfur ratio, and delivery rate of hydrogen sulfide.The radical mechanism of the formation of these substances is discussed.
- Papernaya, L. K.,Panova, G. M.,Deryagina, E. N.,Voronkov, M. G.
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p. 1856 - 1862
(2007/10/02)
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- Process of producing high purity bis(4-hydroxyphenyl)sulfides and heat-sensitive recording materials containing the same
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In a process of producing high purity bis(4-hydroxyphenyl)sulfides which comprises reacting phenols with sulfur dichloride in an organic solvent, the improvement comprising: reacting the phenols with sulfur dichloride in a nonpolar organic solvent; removing partly or wholly the nonpolar organic solvent after the reaction; adding a polar organic solvent to the reaction mixture to dissolve the reaction mixture therein at elevated temperatures; and crystallizing out the high purity bis(4-hydroxyphenyl)sulfides. There is further provided a high performance heat-sensitive recording material which comprises high purity bis(4-hydroxy-3-methylphenyl)sulfide thus prepared and having a melting point in the range of from 123.9° C. to 124.9° C. as a developer and a fluoran compound as a color former.
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- Photolysis of Tris(4-tert-butoxycarbonyloxyphenyl)Sulphonium Salts. A Mechanistic Study
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Tris(4-tert-butoxycarbonyloxyphenyl)sulphonium salts of the structure Ar3S+X- (X- : CF3SO3- or AsF6-) were irradiated with UV light in acetonitrile or dimethyl sulphoxide solution.Product analysis by
- Schwalm, Reinhold,Bug, Ruth,Dai, Guang-Song,Fritz, Peter M.,Reinhardt, Michael,et al.
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p. 1803 - 1808
(2007/10/02)
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- Method for preparing aromatic bischloroformate compositions
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Bischloroformate oligomer compositions are prepared by passing phosgene into a heterogeneous aqueous-organic mixture containing at least one dihydroxyaromatic compound, with simultaneous introduction of a base at a rate to maintain a specific pH range and to produce a specific volume ratio of aqueous to organic phase. By this method, it is possible to employ a minimum amount of phosgene. The reaction may be conducted batchwise or continuously. The bischloroformate composition may be employed for the preparation of cyclic polycarbonate oligomers or linear polycarbonate, and linear polycarbonate formation may be integrated with bischloroformate composition formation in a batch or continuous process.
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- Carbonates of acetylenic alcohols
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Polymerizable carbonate compounds of the formula: wherein A is an aromatic polycycle, R1 and R2 are independently hydrogen atom or alkyl, and n is 1, 2 or 3, are disclosed. They are useful as a component of nonemanating, self-curing and heat resistant resin compositions.
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- Bischoloroformate preparation method with phosgene removal and monochloroformate conversion
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Aqueous bischloroformates are prepared by the reaction of a dihydroxyaromatic compound (e.g., bisphenol A) with phosgene in a substantially inert organic liquid (e.g., methylene chloride) and in the presence of an aqueous alkali metal or alkaline earth metal base, at a pH below about 8. After all solid dihydroxyaromatic compound has been consumed, the pH is raised to a higher value in the range of about 7-12, preferably 9-11, and maintained in said range until a major proportion of the unreacted phosgene has been hydrolyzed. At the same time, any monochloroformate in the product may be converted to bischloroformate.
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- Cyclic monocarbonate bishaloformates
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Cyclic monocarbonate bischloroformates are prepared by the reaction of a carbonyl halide such as phosgene with a bridged substituted resorcinol or hydroquinone such as bis(2,4-dihydroxy-3-methylphenyl)methane or bis(2,5-dihydroxy-3,4,6-trimethylphenyl)methane in the presence of aqueous alkali metal hydroxide. The cyclic monocarbonate bischloroformates may be used for the preparation of linear or cyclic polycarbonates containing cyclic carbonate structural units, which may in turn be converted to crosslinked polycarbonates.
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- Polyetherimide bisphenol compositions
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Polyetherimide bisphenols and bischloroformates are prepared by the reaction of dianhydrides or certain bisimides with aminophenols or mixtures thereof with diamines. They are useful as intermediates for the preparation of cyclic heterocarbonates, which may in turn be converted to linear copolycarbonates. The bisphenols can also be converted to salts which react with cyclic polycarbonate oligomers to form block copolyetherimidecarbonates.
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- HIGH-TEMPERATURE ORGANIC SYNTHESIS. XXVII. REACTIONS OF ALKANETHIONES WITH THE CHLORINE DERIVATIVES OF BENZENE, THIOPHENE, AND NAPHTHALENE
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Alkanethiols react effectively with chlorobenzene, its derivatives, 1-chloronaphthalene, and 2-chlorothiophene at 600-660 deg C with the preferential formation of the corresponding aromatic or heteroatomic thiols.Ethanethiol is most reactive.When it is used instead of hydrogen sulfide in reactions with chlorobenzene or its 4-substituted derivatives, the yield of the aromatic thiols, from which the phenylthiyl radicals are generated with greater difficulty, increases more sharply than the yield of the thiophenols, which generate the more stable 4-XC6H4S radicals.The side products of the reactions are the corresponding diaryl sulfides, thiophene, benzothiophene, and toluene.
- Voronkov, M. G.,Deryagina, E. N.,Sukhomazova, E. N.
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p. 755 - 760
(2007/10/02)
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- Vat dye and sulfur dye compositions
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Specific vatting accelerators according to claims 1 and 2 are described. These can be added to a vat dye or sulfur dye composition, or to a dye bath or printing paste containing a vat dye or sulfur dye, by virtue of which an improvement of dye yield, particularly on cellulose materials, is obtained.
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- HIGH TEMPERATURE ORGANIC SYNTHESIS. XIX. MECHANISM OF HIGH-TEMPERATURE REACTION OF AROMATIC CHLORINE DERIVATIVES WITH HYDROGEN SULFIDE
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Quantum-chemical calculations were made in the CNDO/2 approximation for para-substituted chlorobenzene and thiophenol, and the x-ray fluorescence Kα and Kβ spectra of the sulfur in the latter were obtained.The electronic structure parameters of these compounds were compared with their reactivity in high-temperature processess.The reactivity of 4-substituted chlorobenzenes in reaction with hydrogen sulfide in the gas phase correlates with the electron density at the chlorine atom of the chlorine derivative.The direction of this process (the formationof the corresponding thiophenol or diaryl sulfide) is determined by the ability of the thiophenol formed at the first stage to generate sufficiently stable phenylthiyl radicals.The latter are stabilized by a mechanism of ?-conjugation, and the stability increases with increase in the ?-donating character of the para substituent in the aromatic ring. ?-Accepting substituents destabilize the phenylthiyl radicals, increasing the selectivity of the process leading to the production of the respective thiophenol.
- Voronkov, M. G.,Deryagina, E. N.,Dolenko, G. N.,Ivanova, G. M.,Sukhomazova, E. N.,et. al.
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p. 2095 - 2101
(2007/10/02)
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- Cyclic phosphorous acid esters
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Phosphorous acid esters obtained by reacting bisphenols with phosphorous trihalogenide or triphosphite and optionally or mono - or polyhydroxy compound are especially useful for stabilizing polyamides.
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- Rearrangements and decompositions of thiobisphenols
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2,2′-, 2,4′- and 4,4′-Monothiobisphenol separately rearrange in phenol at 180° in the presence of sodium hydroxide to give similar mixtures containing only 2,2′-, 2,4′- and 4,4′-monothiobisphenol in the approximate ratio, 45:45:10. The rearrangements appear to be intermolecular and they are interpreted in terms of polar processes which lead initially to the formation of o- and p-monothiobenzoquinones. 2,2′-Dithiobisphenol, 4,4′-dithiobisphenol and 4,4′-trithiobisphenol under similar conditions are desulphurated with the evolution of hydrogen sulphide also to give mixtures containing only 2,2 - 2,4′- and 4,4′-monothiobisphenol whilst 3,3′-dithiobisphenol is stable in alkaline phenol even after long periods at 180°. Similar initial heterolyses to o- and p-monothiobenzoquinones are suggested as sources of the monothiobisphenols and displacements of sulphide- or hydrosulphide-ions from intermediate benzeneperthiolate ions by carbanions derived from phenol are suggested as sources of the hydrogen sulphide.
- Neale,Bain,Rawlings
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p. 4583 - 4591
(2007/10/05)
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