- Visible-Light-Promoted Oxo-difluoroalkylation of Alkenes with DMSO as the Oxidant
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Visible-light-promoted oxo-difluoroalkylation (acetylation and acetamidation) of alkenes with dimethyl sulfoxide as both the solvent and the oxidant was developed, affording the corresponding α,α-difluoro-?-ketoacetates and acetamides in modest yields. Both terminal and internal alkenes worked well for the reaction. This reaction features simple starting materials, a green oxidant, mild reaction conditions, and highly functional products.
- Xia, Zi-Hao,Gao, Zhong-Hua,Dai, Lei,Ye, Song
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- Six-coordinate nitrosyl and nitro complexes of meso - Tetratolylporphyrinatocobalt with trans sulfur-donor ligands
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By Fourier transform infrared and optical spectroscopy, it has been observed that interactions of dimethyl sulfide and tetrahydrothiophene with nitrosyl and nitro complexes of meso-tetra-p-tolylporphyrinatocobalt [Co(TTP)] lead to the formation of previou
- Kurtikyan, Tigran S.,Gulyan, Gurgen M.,Dalaloyan, Arina M.,Kidd, Bryce E.,Goodwin, John A.
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- The reactivity of (Me3Si)3SiH with sulfoxides under free radical conditions
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The radical-initiated reaction of (Me3Si)3SiH with a variety of sulfoxides has been investigated. The reactivity varies significantly with the nature of the starting materials. The reactions of diaryl sulfoxides provide the corresponding sulfides in high yields while the related reactions with dialkyl sulfoxides occur more slowly and in moderate yields. The rate constant for the addition of (Me3Si)3Si[rad] radical with dibutyl sulfoxide is in the range 103–104M?1s?1at 80 °C. The reactivity of (Me3Si)3SiH with 1,3-dithiolane derivatives has also been investigated in a comparative study. The 2,2-dimethyl-1,3-dithiolane and the corresponding 1,1-dioxide give very smooth reaction with (Me3Si)3Si[rad] radical attack at sulfur followed by the ring opening at S–CMe2bond and subsequent H-abstraction from the silane in very high yield, whereas the 2,2-dimethyl-1,3-dithiolane-1-oxide behaves quite differently and unexpectedly.
- Chatgilialoglu, Chryssostomos,Ferreri, Carla
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- Characterization and catalytic performance of {Mo2O2S2}-based oxothiomolybdenum cyclic clusters supported on mesoporous SBA-15
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Cyclic polyoxothiomolybdate clusters containing {Mo2O2S2} building unit supported on SBA-15 have been prepared by immersion SBA-15 in the corresponding cluster's solution. The measurements of low angle X-ray diffraction (L
- Xin, Zhifeng,Wei, Wei,Chen, Min,Jia, Ai-Quan,Zhang, Qian-Feng
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- Synthesis, structure, and reactions of a copper-sulfido cluster comprised of the parent Cu2S unit: {(NHC)Cu}2(μ-S)
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The synthesis of the first CuI2(μ-S) complex, {(IPr?)Cu}2(μ-S) (IPr? = 1,3-bis(2,6-(diphenylmethyl)-4-methylphenyl)imidazol-2-ylidene; 1), has been accomplished via three synthetic routes: (1) salt metathesis between (IPr?)CuCl and Na2S; (2) silyl-deprotection reaction between (IPr?)Cu(SSiMe3) and (IPr?)CuF; and (3) acid-base reaction between (IPr?)Cu(SH) and (IPr?)Cu(OtBu). The X-ray crystal structure of 1 exhibits two two-coordinate copper centers connected by a bent Cu-S-Cu linkage. Application of these synthetic routes to analogous precursors containing the sterically smaller ligand IPr (1,3-bis(2,6-di-isopropylphenyl)imidazol-2-ylidene), in place of IPr?, resulted in the formation of a transient product proposed as {(IPr)Cu}2(μ-S) (2), which decomposes quickly in solution. The instability of 2 probably results from the insufficient steric protection provided by IPr ligands to the unsaturated Cu2(μ-S) core; in contrast, 1 is stable both in solution and solid state for weeks. The nucleophilic sulfido ligand in 1 reacts with haloalkyl electrophiles (benzyl halides and dibromoalkanes) with formation of C-S bonds, affording (IPr?)Cu(SCH2Ph) and cyclic thioethers, respectively.
- Zhai, Junjie,Filatov, Alexander S.,Hillhouse, Gregory L.,Hopkins, Michael D.
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- The synthesis of polymeric sulfides by reaction of dihaloalkanes with sodium sulfide
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Several poly(alkylene sulfide)s have been synthesized in excellent yields from reactions of α,ω-dibromo- and/or α,ω- dichloroalkanes with sodium sulfide nonahydrate under reflux conditions. The procedure is general, simple and convenient for the production of various poly(alkylene sulfide)s and the way reaction parameters influence the properties of the polymers formed has been examined.
- Smith, Keith,El-Hiti, Gamal A.,Al-Zuhairi, Ali J.
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- Coenzyme F430 from Methanogenic Bacteria: Methane Formation by Reductive Carbon-Sulphur Bond Cleavage of Methyl Sulphonium Ions Catalysed by F430 Pentamethyl Ester
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The nickel(I)-form of coenzyme F430 pentamethyl ester is an efficient catalyst for the reductive cleavage of methyl sulphonium salts to methane and thioesters.
- Jaun, Bernhard,Pfaltz, Andreas
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- Neutral and Anionic Binuclear Perhalogenophenyl Platinum-Silver Complexes with Pt->Ag Bonds Unsupported by Covalent Bridges. Molecular Structures of , and (tht = tetrahydrothiophene)
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Heterobinulear complexes of general formula 14-21 have been prepared by treating the anionic platinum derivatives with (molar ratio 1:1) in dichloromethane.The anionic (L = OEt2, PPh3 or tht) 22-24 and 25 have been obtained from the corresponding 2 and (molar ratio 1:1) in CH2Cl2-diethyl ether.The reaction between and renders Ag(C6F5) and cis-.The salts 2 and 24> react with yielding and , respectively.The reactions between 2 and or (molar ratio 1:2) render in the first case complex 24 while in the second an unstable material which evolves to 27 is obtained. The reaction between 2 (X = F or Cl) and or ClO4 have also been studied.The structures of 14, 24 and 25 have been established by single-crystal X-ray diffraction studies.The complexes contain a strong Pt->Ag bond unsupported by covalent bridges, and short contacts between the o-F or o-Cl atoms of the C6X5 (X = F or Cl) groups and the Ag atom are present.The relative strength of such contacts is discussed.Methods for the synthesis of mixed pentachloro-pentafluorophenyl starting complexes 1-13 have been investigated.
- Uson, Rafael,Fornies, Juan,Tomas, Milagros,Ara, Irene,Casas, Jose M.,Martin, Antonio
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- Efficient reduction of sulfoxides with 2,6-dihydroxypyridine
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2,6-Dihydroxypyridine was found to be an efficient reagent in the deoxygenation of sulfoxides. The mild reaction conditions were compatible with functional groups such as ester and carbamate. It was also found that approximately 0.25 equivalents of 2,6-dihydroxypyridine was required for effective reduction. (C) 2000 Elsevier Science Ltd.
- Miller, Samantha J.,Collier, Talia R.,Wu, Weiming
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- Formation of active sites and hydrodesulfurization activity of rhodium phosphide catalyst: Effect of reduction temperature and phosphorus loading
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Effects of reduction temperature and phosphorus loading on rhodium phosphide (Rh2P) formation and on the catalytic activity of Rh-xP catalysts for hydrodesulfurization (HDS) were investigated to prepare highly active HDS catalysts. Analysis of the Rh-xP catalysts showed that a suitable P loading for HDS activity is 1.5 wt% - four times greater than that of an Rh catalyst. Temperature-programmed reduction and X-ray diffraction analyses of the Rh-xP catalysts showed that Rh2P is readily formed in catalysts with higher P loading. In contrast, the results of transmission electron microscopy observation and CO adsorption experiments indicated that the Rh2P particle size increased with increasing P content. Thus, the high HDS activity of the Rh-1.5P catalyst was explained by the formation of small Rh2P at a relatively low reduction temperature (550°C).
- Kanda, Yasuharu,Temma, Chisato,Sawada, Ayaka,Sugioka, Masatoshi,Uemichi, Yoshio
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- Catalytic dehydrogenation of amines to imines and the in-situ reduction of sulfoxides into sulfides
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The catalytic acceptorless dehydrogenation of primary amines into imines and H2 represents one of the most important organic transformations, and the in-situ utilization of the generated H2 for chemical reduction reactions has never
- Li, Bo,Liu, Bing,Liu, Xixi,Wang, Wei,Wang, Yanxin,Xiang, Nian,Zhang, Zehui
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- Preparation method of N-(4-methylpyridine-3-yl) methyl carbamate
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The invention relates to the technical field of preparation methods of N-(4-methylpyridine-3-yl) methyl carbamate, and discloses preparation of potassium tert-butoxide and preparation of the potassium tert-butoxide by using potassium methoxide. According to the preparation method of the N-(4-methylpyridine-3-yl) methyl carbamate, a user uses the potassium methoxide to prepare the potassium tert-butoxide, so that the content of the potassium tert-butoxide is higher, the potassium tert-butoxide and the potassium methoxide are very similar in properties and functions, so that the cost is saved, the method for extracting a THT solvent by using 1, 4-dichlorobutene as a raw material is simple, and the method has the advantages that the use amount of the catalyst is small, the condition is mild, the extraction purity is high, so that the cost is reduced again; and the N-(4-methylpyridine-3-yl) methyl carbamate is obtained by catalyzing two high-purity raw materials through the catalyst carbonic acid diester and stirring, so that the preparation efficiency is improved, the purity of the prepared N-(4-methylpyridine-3-yl) methyl carbamate is improved, the over-high preparation cost of the N-(4-methylpyridine-3-yl) methyl carbamate is avoided, and the use of the user is facilitated.
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Paragraph 0020; 0022; 0025-0026; 0030; 0032; 0035-0036
(2021/06/02)
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- Lewis Acidic Boranes, Lewis Bases, and Equilibrium Constants: A Reliable Scaffold for a Quantitative Lewis Acidity/Basicity Scale
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A quantitative Lewis acidity/basicity scale toward boron-centered Lewis acids has been developed based on a set of 90 experimental equilibrium constants for the reactions of triarylboranes with various O-, N-, S-, and P-centered Lewis bases in dichloromethane at 20 °C. Analysis with the linear free energy relationship log KB=LAB+LBB allows equilibrium constants, KB, to be calculated for any type of borane/Lewis base combination through the sum of two descriptors, one for Lewis acidity (LAB) and one for Lewis basicity (LBB). The resulting Lewis acidity/basicity scale is independent of fixed reference acids/bases and valid for various types of trivalent boron-centered Lewis acids. It is demonstrated that the newly developed Lewis acidity/basicity scale is easily extendable through linear relationships with quantum-chemically calculated or common physical–organic descriptors and known thermodynamic data (ΔH (Formula presented.)). Furthermore, this experimental platform can be utilized for the rational development of borane-catalyzed reactions.
- Mayer, Robert J.,Hampel, Nathalie,Ofial, Armin R.
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supporting information
p. 4070 - 4080
(2021/01/29)
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- Photocatalytic Deoxygenation of Sulfoxides Using Visible Light: Mechanistic Investigations and Synthetic Applications
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The photocatalytic deoxygenation of sulfoxides to generate sulfides facilitated by either Ir[(dF(CF3)ppy)2(dtbbpy)]PF6 or fac-Ir(ppy)3 is reported. Mechanistic studies indicate that a radical chain mechanism operates, which proceeds via a phosphoranyl radical generated from a radical/polar crossover process. Initiation of the radical chain was found to proceed via two opposing photocatalytic quenching mechanisms, offering complementary reactivity. The mild nature of the radical deoxygenation process enables the reduction of a wide range of functionalized sulfoxides, including those containing acid-sensitive groups, in typically high isolated yields.
- Clarke, Aimee K.,Parkin, Alison,Rossi-Ashton, James A.,Taylor, Richard J. K.,Unsworth, William P.
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p. 5814 - 5820
(2020/07/21)
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- Nickel phosphide nanoalloy catalyst for the selective deoxygenation of sulfoxides to sulfides under ambient H2pressure
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Exploring novel catalysis by less common, metal-non-metal nanoalloys is of great interest in organic synthesis. We herein report a titanium-dioxide-supported nickel phosphide nanoalloy (nano-Ni2P/TiO2) that exhibits high catalytic activity for the deoxygenation of sulfoxides. nano-Ni2P/TiO2 deoxygenated various sulfoxides to sulfides under 1 bar of H2, representing the first non-noble metal catalyst for sulfoxide deoxygenation under ambient H2 pressure. Spectroscopic analyses revealed that this high activity is due to cooperative catalysis by nano-Ni2P and TiO2. This journal is
- Fujita, Shu,Mitsudome, Takato,Mizugaki, Tomoo,Yamaguchi, Sho,Yamasaki, Jun,Yamazoe, Seiji
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supporting information
p. 8827 - 8833
(2020/11/23)
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- A Manganese N-Heterocyclic Carbene Catalyst for Reduction of Sulfoxides with Silanes
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The first reduction of sulfoxides catalysed by a well-defined manganese complex is described. A variety of sulfoxides are reduced to the corresponding sulfides in high yields using phenylsilane, diphenylsilane, and the economically feasible 1,1,3,3-tetramethyldisiloxane (TMDS) as reducing agents in the presence of a Mn-NHC complex. The reaction is performed under air and without the need of any additive. The involvement of radicals in the catalytic reaction is probed by spin-trap experiments.
- Sousa, Sara C. A.,Carrasco, Carlos J.,Pinto, Mara F.,Royo, Beatriz
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p. 3839 - 3843
(2019/06/24)
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- Efficient Chemoselective Reduction of N-Oxides and Sulfoxides Using a Carbon-Supported Molybdenum-Dioxo Catalyst and Alcohol
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The chemoselective reduction of a wide range of N-oxides and sulfoxides with alcohols is achieved using a carbon-supported dioxo-molybdenum (Mo@C) catalyst. Of the 10 alcohols screened, benzyl alcohol exhibits the highest reduction efficiency. A variety of N-oxide and both aromatic and aliphatic sulfoxide substrates bearing halogens as well as additional reducible functionalities are efficiently and chemoselectively reduced with benzyl alcohol. Chemoselective N-oxide reduction is effected even in the presence of potentially competing sulfoxide moieties. In addition, the Mo@C catalyst is air- and moisture-stable, and is easily separated from the reaction mixture and then re-subjected to reaction conditions over multiple cycles without significant reactivity or selectivity degradation. The high stability and recyclability of the catalyst, paired with its low toxicity and use of earth-abundant elements makes it an environmentally friendly catalytic system.
- Li, Jiaqi,Liu, Shengsi,Lohr, Tracy L.,Marks, Tobin J.
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p. 4139 - 4146
(2019/05/27)
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- Mild Deoxygenation of Sulfoxides over Plasmonic Molybdenum Oxide Hybrid with Dramatic Activity Enhancement under Visible Light
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Harvesting solar light to boost commercially important organic synthesis still remains a challenge. Coupling of conventional noble metal catalysts with plasmonic oxide materials which exhibit intense plasmon absorption in the visible light region is a promising option for efficient solar energy utilization in catalysis. Herein, we for the first time demonstrate that plasmonic hydrogen molybdenum bronze coupled with Pt nanoparticles (Pt/HxMoO3-y) shows a high catalytic performance in the deoxygenation of sulfoxides with 1 atm of H2 at room temperature, with dramatic activity enhancement under visible light irradiation relative to dark conditions. The plasmonic molybdenum oxide hybrids with strong plasmon resonance peaks pinning at around 556 nm are obtained via a facile H-spillover process. Pt/HxMoO3-y hybrid provides excellent selectivity for the deoxygenation of various sulfoxides as well as pyridine N-oxides, in which drastically improved catalytic efficiencies are obtained under the irradiation of visible light. Comprehensive analyses reveal that oxygen vacancies massively introduced via a H-spillover process are the main active sites, and the reversible redox property of Mo atoms and strong plasmonic absorption play key roles in this reaction. The catalytic system works under extremely mild conditions and can boost the reaction by the assistance of visible light, offering an ultimately greener protocol to produce sulfides from sulfoxides. Our findings may open up a new strategy for designing plasmon-based catalytic systems that can harness visible light efficiently.
- Kuwahara, Yasutaka,Yoshimura, Yukihiro,Haematsu, Kohei,Yamashita, Hiromi
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p. 9203 - 9210
(2018/06/25)
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- A one-pot high-yield producing method for tetrahydrothiophene
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The invention relates to a one-pot high-yield producing method for tetrahydrothiophene. The method includes adding 164-205 kg of anhydrous sodium sulfide having a content of 60%, 480-800 kg of a solvent and 3.2-9.6 kg of a phase transfer catalyst into an enamel reactor having a volume of 1500 L, heating under stirring, maintaining the reaction temperature to be 50-100 DEG C, adding dropwise 160 kg of 1,4-dichlorobutane into the reactor, maintaining the temperature for 3-6 h after the addition is finished, heating to 115-122 DEG C, and performing atmospheric distillation by adopting an enamel filler column to obtain a tetrahydrothiophene high-quality product. The purity of the product of the method can be 99%, and the yield is higher than 95%. The method is high in product yield and purity, low in environment pollution, low in cost and suitable for industrial production.
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Paragraph 0019-0020; 0042-0043; 0045
(2017/05/27)
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- B(C 6 F 5) 3 -Catalyzed Reduction of Sulfoxides and Sulfones to Sulfides with Hydrosilanes
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B(C 6 F 5) 3 is shown to catalyze the deoxygenation of sulfoxides and sulfones to the corresponding sulfides with Et 3 SiH as the stoichiometric hydride source. While the method is limited in terms of functional group tolerance, it is applicable to the reduction of alkyl/aryl-, aryl/aryl-, and alkyl/alkyl-substituted sulfoxides, including the benzyl/benzyl-substituted derivative. The same protocol converts alkyl/aryl- but not aryl/aryl-substituted sulfones into sulfides.
- Porwal, Digvijay,Oestreich, Martin
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p. 4698 - 4702
(2017/10/05)
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- Tetrahydrothiophene synthesis method and process
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The invention relates to a tetrahydrothiophene synthesis method and a tetrahydrothiophene synthesis process in the field of fine chemicals. According to the method, 1,4-butylene glycol and hydrogen sulfide are adopted as raw materials, and reaction is carried out in the presence of a modified catalyst. The method comprises the following steps: heating the 1,4-butylene glycol and the hydrogen sulfide to reaction temperature, causing a vaporization product to enter a heated fixed bed reactor to be reacted by a prepared catalyst in a fixed bed after vaporization of a heat exchanger, causing a reaction product to enter a distillation column for further separation after heat exchange, further performing oil-water separation after a separation product passes through a condenser, and collecting tetrahydrothiophene. According to the tetrahydrothiophene synthesis method and the tetrahydrothiophene synthesis process, the raw materials are low in cost and readily available, the tetrahydrothiophene synthesis method and the tetrahydrothiophene synthesis process are high in catalyst selectivity, lower in reaction temperature, less in investment and suitable for industrial production, and the reaction energy consumption is reduced.
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Paragraph 0025; 0027
(2017/07/20)
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- One-Pot Intermolecular C–S Self-Coupling of Dimethyl Sulfoxide Promoted by Molybdenum Pentachloride
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The reactions between MoCl5and 1–2 equiv. of a selection of sulfoxides at room temperature in dichloromethane as solvent were studied. The 1:1 molar reaction between MoCl5and dimethyl sulfoxide (DMSO) afforded the C–S coupling product [Me2SCH2SMe][MoOCl4] (1), which was isolated in 46 % yield and characterized by analytical and spectroscopic methods and by X-ray diffraction. MoOCl3, SMe2and HCl were identified as side products. The reactions between MoCl5and tetrahydrothiophene 1-oxide, nBu2SO, MePhSO or (PhCH2)2SO yielded the corresponding sulfides and, in the cases of (PhCH2)2SO and MePhSO, also C–S activation compounds. According to DFT calculations, the unusual formation of 1 is the consequence of thermodynamically feasible Cl/O interchange between MoCl5and DMSO, this being a prerequisite for successive C–H bond activation.
- Bortoluzzi, Marco,Ferretti, Eleonora,Hayatifar, Mohammad,Marchetti, Fabio,Pampaloni, Guido,Zacchini, Stefano
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p. 3838 - 3845
(2016/08/19)
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- Synthesis of common-sized heterocyclic compounds by intramolecular cyclization over halide cluster catalysts
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Five- to seven-membered common-sized heterocyclic compounds containing an oxygen, sulfur, or nitrogen were synthesized by the intramolecular condensation of α,ω-hydroxy, mercapto, or amino alkanes, respectively, over halide cluster complexes as a thermally stable molecular solid weak acid catalyst in the gas phase at temperatures ≥150 °C. From ω- mercapto and ω-amino alcohols, cyclic sulfides and amines were obtained, respectively. These unimolecular reactions are thermodynamically and kinetically favored.
- Nagashima, Sayoko,Sasaki, Tomoaki,Kamiguchi, Satoshi,Chihara, Teiji
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supporting information
p. 764 - 766
(2015/06/22)
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- Efficient Oxidation of Sulfides to Sulfoxides and Deoxygenation of Sulfoxides over Carbonaceous Solid Acid
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Carbonaceous Solid Acid (CSA) was found to be a highly efficient, environmentally friendly, recyclable heterogeneous solid acid for the oxidation of sulfides and deoxygenation of sulfoxides, in good to excellent yields under mild reaction conditions.
- Atabaki, Fariborz,Abedini, Ebrahim,Shokrolahi, Arash
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p. 1169 - 1176
(2015/08/04)
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- Ruthenium nanoparticles supported on magnesium oxide: A versatile and recyclable dual-site catalyst for hydrogenation of mono- and poly-cyclic arenes, N-heteroaromatics, and S-heteroaromatics
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The development of catalysts capable of promoting hydrogenation of aromatics while being resistant to poisoning by nitrogen- and sulfur-containing species is of much interest in connection with hydrotreating of fossil fuels. We report a catalyst composed of ruthenium nanoparticles supported on magnesia, designed to promote heterolytic hydrogen splitting and surface ionic hydrogenation pathways. The catalyst, prepared through a one-pot procedure, promotes the hydrogenation of mono- and poly-cyclic arenes, as well as N- and S-heteroaromatics representative of fossil fuels components. Of particular significance are the superior activity and wider substrate scope of the catalyst, in relation to other known supported noble metals, and the excellent recyclability and long catalyst lifetime. Based on our experimental data, a dual-site catalyst structure and an associated dual-pathway mechanism are proposed, which may have interesting implications for the development of new poison-tolerant noble metal catalytic systems.
- Fang, Minfeng,Sanchez-Delgado, Roberto A.
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p. 357 - 368
(2014/02/14)
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- A novel method for the reduction of sulfoxides with the N, N, N g, N g-tetrabromobenzene-1,3-disulfonamide (TBBDA)/PPh3 system
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A new method is described for the reduction of sulfoxides to sulfides using N,N,N',N'-tetrabromobenzene-1,3-disulfonamide [TBBDA] in combination with triphenylphosphine. Good to excellent yields, short reaction times, high efficiency and facile isolation of the desired products are the advantages of this method.
- Ghorbani-Vaghei, Ramin,Shiri, Lotfi,Ghorbani-Choghamarani, Arash
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p. 1002 - 1006
(2014/12/10)
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- Oxo-rhenium(V) complexes containing heterocyclic ligands as catalysts for the reduction of sulfoxides
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This work reports the catalytic activity of a large variety of oxo-rhenium(V) complexes (1 mol-%) containing the ligands 2-(2-hydroxy-5- methylphenyl)benzotriazole (Hhmpbta), 2-(2-hydroxyphenyl)benzothiazole (Hhpbt), 2-(2-hydroxyphenyl)benzoxazole (Hhpbo), and 2-(2-hydroxyphenyl)-1H-benzimidazole (Hhpbi) in the deoxygenation of sulfoxides with silanes or boranes as the reducing agents. In general, all of the complexes are excellent catalysts, although the PhSiH3/[ReOBr2(hmpbta)(PPh3)] and pinacolborane/[ReOBr2(hmpbta)(PPh3)] systems are the most efficient for the reduction of aromatic and aliphatic sulfoxides and tolerate different functional groups. Copyright
- Sousa, Sara C. A.,Bernardo, Joana R.,Wolff, Mariusz,Machura, Barbara,Fernandes, Ana C.
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p. 1855 - 1859
(2014/04/03)
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- Oxo-Rhenium(V) Complexes Containing Heterocyclic Ligands as Catalysts for the Reduction of Sulfoxides
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This work reports the catalytic activity of a large variety of oxo-rhenium(V) complexes (1 mol-%) containing the ligands 2-(2-hydroxy-5-methylphenyl)benzotriazole (Hhmpbta), 2-(2-hydroxyphenyl)benzothiazole (Hhpbt), 2-(2-hydroxyphenyl)benzoxazole (Hhpbo), and 2-(2-hydroxyphenyl)-1H-benzimidazole (Hhpbi) in the deoxygenation of sulfoxides with silanes or boranes as the reducing agents. In general, all of the complexes are excellent catalysts, although the PhSiH3/[ReOBr2(hmpbta)(PPh3)] and pinacolborane/[ReOBr2(hmpbta)(PPh3)] systems are the most efficient for the reduction of aromatic and aliphatic sulfoxides and tolerate different functional groups.
- Sousa, Sara C. A.,Bernardo, Joana R.,Wolff, Mariusz,Machura, Barbara,Fernandes, Ana C.
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p. 1855 - 1859
(2015/10/05)
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- Reduction of sulfoxides and pyridine-N-oxides over iron powder with water as hydrogen source promoted by carbon dioxide
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A green process was developed for efficient reduction of sulfoxides and pyridine-N-oxides using the iron powder in the presence of H2O- CO2 to sulfides and pyridines, respectively. Notably, H2O is employed as the terminal hydrogen source, and CO2 could enhance hydrogen generation through in situ formation of carbonic acid. Thus carbonic acid offers simple neutralization by depressurizing CO2 and the system can eliminate unwanted byproducts. The high generality and chemo-selectivity of this protocol were demonstrated by the scope of substrates, in which chlorine, vinyl group and benzene ring can be tolerated.
- Ma, Ran,Liu, An-Hua,Huang, Cheng-Bin,Li, Xue-Dong,He, Liang-Nian
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supporting information
p. 1274 - 1279
(2013/06/05)
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- Synthesis of 3,6-diaryl-1,4,5-thiadiazepines from substituted 2-thiocyano acetophenone and investigation of reaction mechanism
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In this work, we have studied the reaction of substituted 2-thiocyanoacetophenone and hydrazine hydrate as a novel and simple pathway for the preparation of the substituted 1,4,5-thiodiazepine ring system. The mechanism of this reaction revealed that in the initial step condensation of hydrazine with carbonyl groups of substituted 2-thiocyanoacetophenons 2a-2f gives the corresponding substituted aromatic dithiocyano azide intermediates which in turn undergo cyclization to1,4,5-thiadiazepines in the presence of hydrazine. This cyclization is a novel method for the preparation of sulfide bond from the reaction of hydrazine and a dithiocyano intermediate. An account of the reaction mechanism is given.
- Rahimizadeh,Feizyzadeh,Bakavoli,Eshghi
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p. 276 - 283
(2013/08/26)
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- Asymmetric hydrogenation of thiophenes and benzothiophenes
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An efficient and highly asymmetric ruthenium-N-heterocyclic carbene-catalyzed hydrogenation of substituted thiophenes and benzothiophenes is described, providing a new strategy for the formation of valuable enantiomerically pure tetrahydrothiophenes and 2,3-dihydrobenzothiophenes.
- Urban, Slawomir,Beiring, Bernhard,Ortega, Nuria,Paul, Daniel,Glorius, Frank
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supporting information
p. 15241 - 15244
(2012/11/07)
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- Deoxygenation of sulfoxides to sulfides in the presence of zinc catalysts and boranes as reducing reagents
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In the present study, the zinc-catalyzed deoxygenation of aliphatic and aromatic sulfoxides in the presence of boranes as reducing reagent has been explored. After investigation of different reaction parameters the abilities of catalytic amounts of Zn(OTf)2 has been demonstrated in the deoxygenation of various sulfoxides. Moreover, various experiments have been performed to shed light on the underlying reaction mechanism.
- Enthaler, Stephan,Krackl, Sebastian,Irran, Elisabeth,Inoue, Shigeyoshi
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p. 1003 - 1010
(2012/10/29)
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- Unprecedented synthesis of iron-NHC complexes by C-H activation of imidazolium salts. Mild catalysts for reduction of sulfoxides
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A direct synthesis of bidentate cyclopentadienyl-functionalised NHC-iron(ii) complexes by using imidazolium salts and commercially available Fe3(CO)12 is developed. These well-defined iron-NHC complexes efficiently catalyse the reduction of sulfoxides under mild conditions. Radical scavenging experiments indicate the presence of free radicals in the catalytic reaction. The Royal Society of Chemistry 2012.
- Cardoso, Joao M.S.,Royo, Beatriz
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scheme or table
p. 4944 - 4946
(2012/06/01)
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- Zinc-catalyzed deoxygenation of sulfoxides to sulfides applying [B(Pin)]2 as deoxygenation reagents
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In the present study, the zinc-catalyzed deoxygenation of aliphatic and aromatic sulfoxides in the presence of 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi-1, 3, 2-dioxaborolane [B(Pin)]2 as reducing reagent to produce the corresponding sulfides has been investigated. After examination of various reaction parameters the abilities of catalytic amounts of Zn(OTf)2 has been proven in the deoxygenation of various sulfoxides. Especially, a high functional group tolerance was noticed for the Zn(OTf)2/ B(Pin) 2 system. Springer Science+Business Media, LLC 2012.
- Enthaler, Stephan
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p. 1306 - 1311
(2013/01/15)
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- Mild and efficient CO-mediated eliminative deoxygenation of epoxides catalyzed by supported gold nanoparticles
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Supported gold nanoparticles (NPs), which are well-known epoxidation catalysts, were found to be exceptionally active for the selective deoxygenation of epoxides into alkenes using cheap and easily accessible CO and H 2O as the reductant. The Royal Society of Chemistry 2011.
- Ni, Ji,He, Lin,Liu, Yong-Mei,Cao, Yong,He, He-Yong,Fan, Kang-Nian
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supporting information; experimental part
p. 812 - 814
(2011/04/15)
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- Cyanuric chloride as promoter for the oxidation of sulfides and deoxygenation of sulfoxides
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This Letter discusses the use of cyanuric chloride as an efficient promoter for the chemoselective oxidation of sulfides to the corresponding sulfones in the presence of H2O2 as the terminal oxidant. Sulfoxides were also found to undergo deoxygenation to sulfides with cyanuric chloride and potassium iodide system. The reaction is broad in scope and easy to perform.
- Bahrami, Kiumars,Khodaei, Mohammad M.,Sohrabnezhad, Samira
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experimental part
p. 6420 - 6423
(2011/12/21)
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- Reduction of sulfoxides to sulfides in the presence of copper catalysts
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Copper complexes catalyze the reduction of aliphatic and aromatic sulfoxides in the presence of silanes as reducing reagent. The influence of different reaction parameters on the catalytic activity is investigated in detail. The scope and limitations of the described catalyst is demonstrated in the reduction of various sulfoxides. In most cases, high conversion and excellent chemoselectivity are obtained. Graphical Abstract: [Figure not available: see fulltext.]
- Enthaler, Stephan,Weidauer, Maik
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experimental part
p. 833 - 838
(2012/02/14)
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- Chlorination of various substrates in subcritical carbon tetrachloride
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Various aliphatic hydrocarbons and the side chains of aromatic hydrocarbons were chlorinated in subcritical carbon tetrachloride. Chlorination of aromatic compounds including 1,4-disubstituted benzenes was investigated. Ketones and sulfones were stable under the employed conditions. Sulfoxides were converted into sulfides in a low to modest yields. The coupling adducts between olefins and carbon tetrachloride were obtained from the reactions of olefins.
- Tanemura, Kiyoshi,Suzuki, Tsuneo,Nishida, Yoko,Horaguchi, Takaaki
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experimental part
p. 2881 - 2888
(2010/06/16)
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- RuO2 clusters within LTA zeolite cages: Consequences of encapsulation on catalytic reactivity and selectivity
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(Figure Presented) Trapped! The title system (ca. 1 nm diameter; left) catalyzes methanol oxidation with higher turnover rates than clusters on SiO2 supports. Spatial constraints lead to the preferential oxidation of methanol over larger alcohols. Restricted access to active sites also protects encapsulated Ru clusters (right) against inhibition of ethene hydrogenation by organosulfur compounds.
- Zhan, Bi-Zeng,Iglesia, Enrique
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p. 3697 - 3700
(2008/03/11)
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- Dibromoborane-dimethyl sulfide: A new, mild, chemoselective reagent for the rapid deoxygenation of sulfoxides to sulfides
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Dibromoborane-dimethyl sulfide chemoselectively deoxygenates aliphatic and aromatic sulfoxides to the corresponding sulfides in excellent chemical yields in CH2Cl2 solvent in 15 minutes at both 0°C and room temperature, in the presence of reducible functional groups, such as alkene, ketone, ester, lactone, nitrile, amide, azide, sulfone, and N-oxide.
- Roy, Chandra D.,Brown, Herbert C.
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p. 642 - 644
(2007/10/03)
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- Synthesis of hexylselenol and hexylselenides from hexylthiol involving hexylthiolanium salts
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Selenium nucleophiles react regioselectively at the endocyclic or exocyclic carbon of hexylthiolanium salts depending upon the nature of the salt. Georg Thieme Verlag Stuttgart.
- Krief, Alain,Dumont, Willy,Robert, Michael
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p. 2601 - 2604
(2008/09/16)
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- PREPARATION OF ALPHA-HYDROXYKETONES
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A process for the preparation of an 1, 1 -disubstituted oxirane is disclosed, wherein an organic sulphide is reacted in a polar solvent with an educt containing a leaving group attached to a primary or secondary carbon atom, and/or the sulfonium salt formed in this way is reacted with a ketone in presence of a base and a polar solvent. Oxiranes of the type obtained may be further converted into the corresponding α-hydroxyketone or α-aminoketone, either in one step by subjecting to aerobic oxidation in the presence of a transition metal catalyst, or in two steps by hydrolyzation in the presence of an aqueous acid to the corresponding dialcohol and subsequent selective oxidation. Further described are some novel epoxide intermediates. The α-hydroxyketones and α-aminoketones thus obtainable are useful inter alga as photoinitiators.
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- A gentle and efficient route for the deoxygenation of sulfoxides using catecholborane (HBcat; cat = 1,2-O2C6H4)
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The addition of catecholborane (HBcat; cat = 1,2-O2C 6H4) to a wide range of sulfoxides affords the corresponding sulfides, dihydrogen, and catBOBcat. The addition of catecholborane (HBcat; cat = 1,2-O2C6H4) to a wide range of sulfoxides affords the corresponding sulfides, dihydrogen, and catBOBcat. The diboron compound catBOBcat acts like a Lewis acid and will coordinate one molecule of the starting sulfoxide. Although deoxygenations with bulky or electron withdrawing sulfoxides are slow, these reactions can be greatly accelerated with the use of excess HBcat or by employing a rhodium catalyst.
- Harrison, Daniel J.,Tam, Nga Chiu,Vogels, Christopher M.,Langler, Richard F.,Baker, R. Thomas,Decken, Andreas,Westcott, Stephen A.
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p. 8493 - 8496
(2007/10/03)
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- Selective deoxygenation of sulfoxides to sulfides with phosphites catalyzed by dichlorodioxomolybdenum(VI)
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Chemoselective deoxygenation of sulfoxides to sulfides was carried out by P(OPh)3 in mild conditions catalyzed by dichlorodioxomolybdenum(VI).
- Sanz, Roberto,Escribano, Jaime,Aguado, Rafael,Pedrosa, Maria R.,Arnaiz, Francisco J.
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p. 1629 - 1632
(2007/10/03)
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- A mild protocol for the deoxygenation of α-hydrogen-containing sulfoxides to the corresponding sulfides
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A mild method for the deoxygenation of α-hydrogen-containing sulfoxides to sulfides is reported. This synthetically useful and operationally simple protocol derives mechanistically from the Swern oxidation methodology.
- Bhatia, Gurpreet S.,Graczyk, Piotr P.
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p. 5193 - 5195
(2007/10/03)
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- PROCESS FOR THE REDUCTION OF SULPHOXIDES TO SULPHIDES
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The present application relates to a new process for the reduction of sulfoxides to sulfides, wherein said process provides the production of a sulfide compound of formula (I), by the reduction of a sulfoxide compound of formula (II): with oxalyl chloride, an alcohol and tertiary amine.
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- Novel sulfonamide-substituted pyrazolopyridine derivatives
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The invention relates to novel pyrazolopyridine derivatives of formula (I) wherein R1 represents H, Cl or NH2, and R2 and R3 form; together with the heteroatoms to which they are bonded, a five to six-membered heterocycle which can be saturated or partially unsaturated, can optionally contain at least one other heteroatom from the group N, O, S and can be optionally substituted. The invention also relates to salts, isomers and hydrates of said derivatives, in the form of stimulators of soluble guanylate cyclase and as agents for treating cardiovascular diseases, hypertonia, thrombo-embolic diseases and ischaemia, sexual dysfunction, inflammations, and diseases of the central nervous system.
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- Mono-, oligo- and poly-3-(1,1-difluoroalkyl)thiophenes and their use as charge transport materials
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Mono-, oligo- and polymers comprising one or more identical or different recurring units of formula I—[(Y)a—(D)b—(Z)c]—??Iwherein D is a 3-(1,1-difluoroalkyl)thiophene group of formula II, 1wherein Y, Z, R1, R2, a, b and c have the meanings defined herein, are useful as semiconductors and charge transport materials.
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- Catalytic hydrogenation of thiophene to thiolane in the gas phase
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The hydrogenation of thiophene in the gas phase in the presence of palladium-sulfide catalyst leads to the production of thiolane and hydrogenolysis products (butane and hydrogen sulfide), which are formed during the decomposition of the thiophene and thi
- Mashkina,Salakhtueva
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p. 546 - 549
(2007/10/03)
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- Synthesis of tetrahydrothiophene from tetrahydrofuran and hydrogen sulfide
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Optimal conditions were found for the synthesis of tetrahydrothiophene from tetrahydrofuran and hydrogen sulfide over cobalt-promoted γ-Al2O3.
- Sharipova,Nasyrov,Sharipov,Mazitov
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p. 105 - 108
(2007/10/03)
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- Method of preparing a thiophene-containing or furan-containing conjugated compound and precursor compound used therein
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The invention relates to a method of preparing thiophene-containing or furan-containing conjugated compounds such as polythiophene. The method uses a precursor compound having tetrahydrothiophene or tetrahydrofuran precursor units having arylthio or alkylthio substituents. The precursor units can be thermally converted into thiophene or furan units. Due to the presence of the precursor units the precursor compound is soluble and can, unlike the corresponding conjugated compound, be processed from solution.
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- Promotion and Inhibition by Hydrogen Sulfide of Thiophene Hydrodesulfurisation over a Sulfide Catalyst
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The reaction of thiophene has been studied between 300 and 400 deg C and 0.1 MPa over a sulfided CoMo-Al2O3 catalyst with various amounts of H2S; besides the usual inhibiting effect, it has been found that low levels of H2S promoted the reaction above 380 deg C.
- Leglise, J.,Gestel, J. van,Duchet, J. C.
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p. 611 - 612
(2007/10/02)
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