- Karl-Fischer-Reaction in Dimethyl Sulfoxide
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The water equivalent (titer) of methanolic Karl-Fischer-reagents rises if dimethyl sulfoxide (DMSO) is used as an additional solvent.It is shown that the probable reason for this observation is the formation of iodine by the reaction between DMSO, iodide and sulfur trioxide.
- Fischer, Wolfgang,Beil, Stefanie,Krenn, Karl-Dieter
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- Efficient uptake of dimethyl sulfoxide by the desoxomolybdenum(iv) dithiolate complex containing bulky hydrophobic groups
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A desoxomolybdenum(iv) complex containing bulky hydrophobic groups and NH...S hydrogen bonds, (Et4N)[MoIV(OSitBuPh2)(1,2-S2-3,6-{(4-tBuC6H4)3CCONH}2C6H2)2], was synthesized. This complex promotes the oxygen-atom-transfer (OAT) reaction of DMSO by efficient uptake of the substrate into the active center. The clean OAT reaction of Me3NO is also achieved. This journal is
- Hasenaka, Yuki,Okamura, Taka-Aki,Onitsuka, Kiyotaka
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- Reaction of Thioanisol with Antimony Pentachloride
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The reaction of antimony pentachloride with thioanisole (5) at -70 deg C leads to the formation of the sulfonium salt 6, whereas at 0 deg C the chlorosulfonium salt 7 is formed.Under similar conditions 4-methylthioanisole (9) is converted into the expected chlorosulfonium salt 10, which decomposed, however, during isolation experiments.
- Hartke, Klaus,Zerbe, Horst-Georg
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- Synthesis, crystal structure and reactivity of a new pentacoordinated chiral dioxomolybdenum(VI) complex
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The novel tridentate chiral ligand 2,6-bis{[(1R,2S,4R)-2-hydroxy-1,3,3-trimethyl-bicyclo[2.2.1]hept-2-yl]}pyridine (1) was readily prepared by reaction of 2,6-dilithiopyridine with (R)-(-)-fenchone. Reaction of 1 with [MoO2(acac)2] resulted in the formation of the new metal-oxo five-coordinated complex [MoO2(ONO)] (2) [ONO = (1 - 2H)]. The reactivity of 2 has been studied and the derivatives [MoS2(ONO)] (3) and [MoO(O2)(ONO)] (4) were prepared. The compounds 1-4 have been characterised by 1H and 13C{1H} NMR, microanalysis and IR spectroscopy. Furthermore, the molecular structures of 1 and 2 have been determined by single-crystal X-ray diffraction. The behaviour of 2 as catalyst in oxotransfer and in nucleophilic substitution of propargylic alcohols reactions has been tested.
- Pedrosa,Escribano,Aguado,Sanz,Díez,Arnáiz
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- Evolution of the surface sulfur composition of a Ru sulfide particle during CH3SH condensation reaction: Sulfur migration from the bulk to the surface
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The condensation of methanethiol (CH3SH) into dimethylsulfide (CH3SCH3), which is a useful test reaction for probing the acid-base character of transition metal sulfide catalysts for carbon-heteroatom hydrogenolysis reactions, shows a systematic deactivation process at the beginning of the reaction before reaching steady-state activity. The solid surface of RuS2 catalyst in equilibrium with the gas phase was examined by various techniques with the aim of understanding the mechanism responsible for this loss of activity, e.g. coke formation, poisoning by the reactant or the products, change in particle size, etc. X-Ray diffraction and elemental analysis showed neither the formation of carbonaceous deposits nor a sintering effect during the catalytic run. In contrast, a modification of the surface composition of the catalyst induced by the reaction was observed using temperature programmed reduction (TPR). This technique showed that large amounts of H2S are detectable after performing the catalytic test. Sulfur mass balance analyses demonstrate that these sulfur species are an integral part of the total sulfur content of the ruthenium sulfide particles. These surface modifications arise from sulfur migration from the bulk to the surface of the particles during reation. Based on these experimental data and on a crystallographic model developed for RuS2, it is proposed that the methanethiol condensation reaction proceeds on monovacant Ru sites.
- Berhault,Lacroix
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- Cobalt hexaamine mediated electrocatalytic voltammetry of dimethyl sulfoxide reductase: Driving force effects on catalysis
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The bacterial molybdoenzyme dimethyl sulfoxide (DMSO) reductase from Rhodobacter capsulatus catalyzes the reduction of DMSO to dimethyl sulfide in anaerobic respiration. In its native state, DMSO reductase is reduced to its active state by a pentaheme cytochrome (DorC). Alternatively, we show that DMSO reductase catalysis may be driven electrochemically using a series of homologous coordination compounds as mediating synthetic electron donors. All mediators are macrocyclic hexaaminecobalt(II) complexes in their active form, differing principally in their redox potentials over a range of about 250 mV. Thus, each complex presents a different reductive driving force to DMSO reductase and this leads to pronounced differences in the electrocatalytic behavior as measured by cyclic voltammetry. Digital simulation of the experimental voltammetry enables the critical features of the catalytic cycle to be extracted.
- Chen, Kuan-I.,McEwan, Alastair G.,Bernhardt, Paul V.
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- FACILE DEOXYGENATION OF SULFOXIDES BY USING METAL/CHLOROMETHYLSILANES
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Deoxygenation of a various kind of sulfoxides including optically active one by Zinc/Dichlorodimethylsilane proceeds under very mild conditions to furnish the corresponding sulfides in high yields.
- Nagasawa, Kazuo,Yoneta, Akemi,Umezawa, Toshiyuki,Ito, Keiichi
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- Dynamics of Competitive Reactions: Endothermic Proton Transfer and Exothermic Substitution
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Dynamics of an endothermic proton-transfer reaction, F- with dimethyl sulfoxide, and an endothermic proton-transfer reaction with a competing exothermic substitution (SN2) channel, F- with borane-methyl sulfide complex, were investigated using a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR) and kinetic modeling. The two proton-transfer reactions have slightly positive and a small negative overall free energy changes, respectively. Energy-dependent rate constants were measured as a function of F- ion translational energy, and the resulting kinetics were modeled with the RRKM (Rice-Ramsperger-Kassel-Marcus) theory. The observed rate constants for the proton-transfer reactions of F - with dimethyl sulfoxide and with borane-methyl sulfide complex are identical, with a value of 0.17 × 10-9 cm3 molecule-1 s-1; for the SN2 reaction, k = 0.90 × 10-9 cm3 molecule-1 s-1 at 350 K. Both proton-transfer reactions have positive entropy changes in the forward direction and show positive energy dependences. The competing SN2 reaction exhibits negative energy dependence and becomes less important at higher energies. The changes of the observed rate constants agree with RRKM theory predictions for a few kcal/mol of additional kinetic energy. The dynamic change of the branching ratio for the competing proton transfer and the substitution reactions results from the competition between the microscopic rate constants associated with each channel.
- Ren, Jianhua,Brauman, John I.
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- Catalytic synthesis of dimethyl sulfi de from dimethyl disulfi de and methanol
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The reaction of dimethyl disulfi de with methanol was studied at atmospheric pressure and temperature of 350°C in the presence of catalysts containing acid and basic sites.
- Mashkina,Khairulina
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- Novel oxidation of hydrogen sulfide by dimethyl sulfoxide in presence of β-cyclodextrin
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Dimethyl sulfoxide is used as an oxidizing agent to oxidize hydrogen sulfide to solid sulfur at room temperatures and normal pressures, in which, β-cyelodextrin plays an important role in this reaction. in this work, when GC-MS, SEM and FTIR spectroscopic
- Yang, Xiaoxia,Zhang, Jianbin,Chang, Yan,Li, Qiang
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- Cavity ring-down spectroscopic study of the reactions of Br atoms and BrO radicals with dimethyl sulfide
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The title reactions were studied using cavity ring-down spectroscopy in 100 Torr of N2 diluent at 278-333 K. The equilibrium constant and rates of the forward and reverse reactions of the Br + DMS ? Br-DMS equilibrium were determined to be K =
- Nakano, Yukio,Goto, Masashi,Hashimoto, Satoshi,Kawasaki, Masahiro,Wallington, Timothy J.
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- Coordination Chemistry of Borane in Solution: Application to a STING Agonist
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Equilibrium constants were determined for ligand exchange reactions of borane complexes with various oxygen, sulfur, nitrogen, and phosphorus nucleophiles in solution, and a binding affinity scale was built spanning a range of 12 orders of magnitude. While the Keq are minimally dependent on the solvent, the rate of ligand exchange varies significantly. The fastest and slowest rates were observed in THF and CDCl3, respectively. Moreover, the ligand exchange rate differs in a very broad range depending on stability of the starting complex. Binding of BH3 was found to be much more sensitive to steric factors than protonation. Comparing nitrogen bases having equal steric properties, a linear correlation of BH3 binding affinity vs. Br?nsted acidity was found. This correlation can be used to quickly estimate the BH3 binding affinity of a substrate if pKa is known. Kinetic studies suggest the ligand exchange to occur as a bimolecular SN2 reaction unless other nucleophilic species were present in the reaction mixture.
- Lemaire, Sébastien,Zhdanko, Alexander,van der Worp, Boris A.
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- Redox-Divergent Construction of (Dihydro)thiophenes with DMSO
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Thiophene-based rings are one of the most widely used building blocks for the synthesis of sulfur-containing molecules. Inspired by the redox diversity of these features in nature, we demonstrate herein a redox-divergent construction of dihydrothiophenes, thiophenes, and bromothiophenes from the respective readily available allylic alcohols, dimethyl sulfoxide (DMSO), and HBr. The redox-divergent selectivity could be manipulated mainly by controlling the dosage of DMSO and HBr. Mechanistic studies suggest that DMSO simultaneously acts as an oxidant and a sulfur donor. The synthetic potentials of the products as platform molecules were also demonstrated by various derivatizations, including the preparation of bioactive and functional molecules.
- Chen, Qing-An,He, Gu-Cheng,Hu, Yan-Cheng,Ji, Ding-Wei,Liu, Heng,Zhang, Xiang-Xin,Zhao, Chao-Yang
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p. 24284 - 24291
(2021/10/08)
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- Dynamics of the dimethyl sulfide exchange of (1,3-diphenylallyl)dimethylsulfonium ions
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The dynamics of the allylic rearrangement of the (1,3-diphenylallyl)dimethylsulfonium ion in CD2Cl2, which proceeds via intermediate 1,3-diphenylallyl cations, has been investigated by variable temperature 1H NMR spectroscopy. At low temperature, the three allylic protons give rise to an AMX system, and the two diastereotopic S-methyl groups resonate at different frequencies. At higher temperature, an AX2 system for the allylic protons and a single signal for the S-methyl groups are observed. The resulting exchange rate constant of (364 ± 2) s–1 at 25°C, which corresponds to the rate of the heterolytic cleavage of the C–S bond, was used to explore the range of validity of the linear free energy relationship log khet(25°C) = sf (Nf + Ef), which describes the rates of heterolytic cleavages by the electrofugality parameter Ef and the solvent-dependent nucleofuge-specific parameters Nf and sf. The observed rate constant corroborates a previous conclusion that two different sets of Nf and sf parameters may exist for the same nucleofuge. Knowledge of whether the reverse bond-forming reaction occurs under activation or under diffusion control is crucial for the choice of the appropriate set of nucleofugality parameters.
- Jüstel, Patrick M.,Mayr, Herbert,Ofial, Armin R.,Rovó, Petra
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- Effect of Zinc Oxide on the Thermal Decomposition of Dimethyl Sulfoxide
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Dimethyl sulfoxide (DMSO) is widely used in the chemical industry. However, it has a non-neglectful thermal runaway risk due to the nature of self-accelerating decomposition near the boiling point. Under the background that zinc oxide (ZnO) may extend the isothermal induction period of thermal decomposition of DMSO, this article conducts an in-depth study for the phenomenon with the techniques such as differential scanning calorimetry (DSC), accelerating rate calorimetry (ARC), gas chromatography-mass spectrometry (GC-MS), X-ray photoelectron spectroscopy (XPS), and X-ray diffractometry (XRD). After being mixed with ZnO, the maximum decomposition rate of DMSO was significantly reduced and the adiabatic induction period of DMSO decomposition was extended by 3.27 times, indicating that the thermal decomposition intensity of DMSO was obviously reduced. It was experimentally demonstrated that ZnO did not change the decomposition pathways of DMSO, but it could promote the decomposition of methanethiol, which was a decomposition intermediate of DMSO and could potentially serve as a promoter on the decomposition of DMSO.
- Chen, Liping,Chen, Wanghua,Guo, Zichao,Li, Huabo,Weng, Shichun,Wu, Wenqian
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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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- Methanesulfinylation of Benzyl Halides with Dimethyl Sulfoxide
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A phenyltrimethylammonium tribromide-mediated nucleophilic substitution/oxygen transformation reaction of benzyl halides with DMSO has been developed. In this transition-metal-free reaction, DMSO acts as not only a solvent but also a "S(O)Me" source, thus providing a convenient method for the efficient and direct synthesis of various benzyl methyl sulfoxides.
- Fu, Duo,Dong, Jun,Du, Hongguang,Xu, Jiaxi
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p. 2752 - 2758
(2020/01/31)
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- Ni-Catalyzed Carboxylation of C(sp2)-S Bonds with CO2: Evidence for the Multifaceted Role of Zn
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Nickel-catalyzed reductive carboxylation reactions of aryl electrophiles typically require the use of metallic reducing agents. At present, the prevailing perception is that these serve as both a source of electrons and as a source of Lewis acids that may aid CO2 insertion into the Ni-C bond. Herein, we provide evidence for the in situ formation of organometallic species from the metallic reductant, a step that has either been ruled out or has been unexplored in catalytic carboxylation reactions with metal powder reductants. Specifically, we demonstrate that Zn(0) acts as a reductant and that Zn(II) generates arylzinc species that might play a role in the C(sp2)-S carboxylation of arylsulfonium salts. Overall, the reductive Ni-catalyzed C(sp2)-S carboxylation reaction proceeds under mild conditions in a non-amide solvent, displays a wide substrate scope, and can be applied to the formal para C-H carboxylation of arenes.
- Yanagi, Tomoyuki,Somerville, Rosie J.,Nogi, Keisuke,Martin, Ruben,Yorimitsu, Hideki
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p. 2117 - 2123
(2020/02/28)
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- Discovery and mechanistic investigation of Pt-catalyzed oxidative homocoupling of benzene with PhI(OAc)2
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We present a Pt-catalyzed direct coupling of benzene to biphenyl. This catalytic reaction employs a cyclometalated platinum(ii) complex [PtMe(bhq)(SMe2)] (bhq = benzo[h]quinolate) with PhI(OAc)2 as an oxidant and does not require an acid, a co-catalyst or a solvent. The reaction kinetics and characterization of potential catalytic species are reported. The reaction is first-order in Pt and second-order in benzene, which implicates the second C-H activation step as rate-determining. A Pt(ii)/Pt(iv) catalytic cycle is suggested. The reaction commences by oxidation of the Pt(ii) complex to give the platinum(iv) species [Pt(bhq)(SMe2)(OAc)2](OAc) followed by C-H activation of benzene to afford the intermediate [PtPh(bhq)(SMe2)(OAc)](OAc) concurrently with the release of HOAc. A second benzene molecule reacts similarly to give the diphenyl intermediate [PtPh2(bhq)(SMe2)](OAc). C-C bond forming reductive elimination ensues to regenerate Pt(ii) and complete the catalytic cycle. The proposed mechanism has been examined by DFT computations, which provide support to experimental findings.
- Abu-Omar, Mahdi M.,Nabavizadeh, S. Masoud,Niroomand Hosseini, Fatemeh,Park, Chan,Wu, Guang
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supporting information
p. 2477 - 2486
(2020/03/05)
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- An efficient method for synthesizing dimethylsulfonio-34S-propionate hydrochloride from 34S8
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Dimethylsulfoniopropionate (DMSP, (2-carboxyethyl)dimethylsulfonium) is a highly abundant compound in marine environments. As a precursor to the climatically active gas, dimethylsulfide (DMS), DMSP connects the marine and terrestrial sulfur cycles. However, the fate of DMSP in microbial biomass is not well understood as only a few studies have performed isotopic labeling experiments. A previously published method synthesized 34S-labeled DMSP from 34S8, but the efficiency was only 26% and required five separate reactions, expensive reagents, and purification of the products of each reaction. In this study, a method of synthesizing 34S-labeled DMSP from 34S8 is described. Improvements include elemental steps, inexpensive reagents, purification of only one intermediate, and less time to complete. The efficiency of this method is 65% and results in pure DMSP with more than 98% isotope enrichment as determined by 1H-nuclear magnetic resonance (NMR) and gas chromatography–mass spectrometry (GC–MS).
- Wirth, Joseph S.,Whitman, William B.
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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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- Phosphonate Decomposition-Induced Polyoxomolybdate Dumbbell-Type Cluster Formation: Structural Analysis, Proton Conduction, and Catalytic Sulfoxide Reduction
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The reaction of MoO42- with a number of phosphonic acids [bis(phosphonomethyl)glycine, R,S-hydroxyphosphonoacetic acid, 1-hydroxyethane-1,1-diphosphonic acid, phenylphosphonic acid, aminotris(methylene phosphonic acid), and 1,2-ethylenediphosphonic acid] under oxidizing (H2O2) hydrothermal conditions at low pH leads to rupture of the P-C bond, release of orthophosphate ions, and generation of the octanuclear, phosphate-bridged, polyoxometalate molybdenum cluster (NH4)5[Mo8(OH)2O24(μ8-PO4)](H2O)2 (POMPhos). This cluster has been fully characterized and its structure determined. It was studied as a proton conductor, giving moderate values of σ = 2.13 × 10-5 S·cm-1 (25 °C) and 1.17 × 10-4 S·cm-1 (80 °C) at 95% relative humidity, with Ea = 0.27 eV. The POMPhos cluster was then thermally treated at 310 °C, yielding (NH4)2.6(H3O)0.4(PO4Mo12O36) together with an amorphous impurity containing phosphate and molybdenum oxide. This product was also studied for its proton conductivity properties, giving rise to an impressively high value of σ = 2.43 × 10-3 S·cm-1 (25 °C) and 6.67 × 10-3 S·cm-1 (80 °C) at 95% relative humidity, 2 orders of magnitude higher than those corresponding to the "as-synthesized" solid. The utilization of POMPhos in catalytic reduction of different sulfoxides was also evaluated. POMPhos acts as an efficient homogeneous catalyst for the reduction of diphenyl sulfoxide to diphenyl sulfide, as a model reaction. Pinacol was used as a low-cost, environmentally friendly, and highly efficient reducing agent. The effects of different reaction parameters were investigated, namely the type of solvent and reducing agent, presence of acid promoter, reaction time and temperature, loading of catalyst and pinacol, allowing to achieve up to 84-99% yields of sulfide products under optimized conditions. Substrate scope was tested on the examples of diaryl, alkylaryl, dibenzyl, and dialkyl sulfoxides and excellent product yields were obtained.
- Armakola, Eirini,Salcedo, Inés R.,Bazaga-García, Montse,Olivera-Pastor, Pascual,Mezei, Gellert,Cabeza, Aurelio,Fernandes, Tiago A.,Kirillov, Alexander M.,Demadis, Konstantinos D.
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supporting information
p. 11522 - 11533
(2019/09/03)
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- Comparison of molybdenum and rhenium oxo bis-pyrazine-dithiolene complexes-in search of an alternative metal centre for molybdenum cofactor models
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A pair of structurally precise analogues of molybdenum and rhenium complexes, [Et4N]/K2[MoO(prdt)2] and K[ReO(prdt)2] (prdt = pyrazine-2,3-dithiolene), were synthesized. These complexes serve as structural models for the active sites of bacterial molybdenum cofactor containing enzymes. They were comprehensively characterized and investigated by NMR, computationally supported IR and resonance Raman spectroscopy, cyclic voltammetry, mass spectrometry, elemental analysis and single-crystal X-ray diffraction. All compiled data are discussed in the context of comparing chemical and electronic structures and consequences thereof. This study constitutes the first investigation of a potential alternative Moco model system bearing rhenium as the central metal in an identical coordination environment to its molybdenum analogue. Structural evaluation revealed a slightly stronger MO bond in the rhenium complex in accordance with spectroscopic results, i.e. observed bond strengths. Thermodynamic parameters for the redox processes MoIV ? MoV and ReIV ? ReV were obtained by temperature dependent cyclic voltammetry. In contrast to molybdenum, rhenium loses entropy upon reduction and its redox potential is more temperature sensitive, indicating more significant differences than the respective diagonal relationship between the two metals in the periodic table might suggest and questioning rhenium's suitability as a functional artificial active site metal.
- Chrysochos, Nicolas,Ahmadi, Mohsen,Wahlefeld, Stefan,Rippers, Yvonne,Zebger, Ingo,Mroginski, Maria Andrea,Schulzke, Carola
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p. 2701 - 2714
(2019/02/27)
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- Transition-Metal-Free Aryl-Heteroatom Bond Formation via C-S Bond Cleavage
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Aryl-heteroatom bonds (C-Het) are almost ubiquitously present in chemical molecules. However, methods for diverse C-Het bond formations from a simple substrate are limited. Herein, we report a convenient and efficient C-S bond transformation of aryl sulfoniums to various C-Het bonds (C-O, C-S, C-Sn, C-Si, C-Se) in the absence of any transition-metal catalyst. These reactions proceeded in mild conditions with a wide substrate scope.
- Zhao, Jian-Nan,Kayumov, Muzaffar,Wang, Dong-Yu,Zhang, Ao
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supporting information
p. 7303 - 7306
(2019/10/02)
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- PROCESS FOR CONVERSION OF DIMETHYL SULFIDE TO METHYL MERCAPTAN
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Disclosed herein are systems and processes involving the catalyzed cleavage reaction of dimethyl sulfide to methyl mercaptan. The catalyzed cleavage reaction can be a standalone system or process, or can be integrated with a methyl mercaptan production plant.
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Paragraph 00101-00103
(2018/03/09)
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- Method for producing dimethyl sulfone from hydrogen sulfide
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The invention discloses a method for producing dimethyl sulfone from hydrogen sulfide. The method includes: (1) subjecting hydrogen sulfide and methyl alcohol to contacting to obtain a mixture containing dimethyl sulfide; optionally, (2) subjecting the mixture containing dimethyl sulfide to gas-liquid separation to obtain a gas-phase material flow and a liquid-phase material flow containing dimethyl sulfide; optionally, (3) cyclically feeding at least part of the gas-phase material flow to the step (1); (4) subjecting the mixture containing dimethyl sulfide or a liquid phase low in hydrogen sulfide content to contact oxidation reaction with an oxidizing agent and titanium silicate molecular sieves to obtain a mixture containing dimethyl sulfone, wherein a mole ratio of the oxidizing agentto dimethyl sulfide is larger than 2. According to the method, continuous production of dimethyl sulfone from hydrogen sulfide is realized, and high raw material conversion rate and dimethyl sulfone selectivity can be obtained even oxidation reaction is carried out under mild conditions.
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Paragraph 0110-0113; 0175-0178; 0201-0204
(2018/12/05)
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- Method for producing dimethyl sulfone from hydrogen sulfide
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The invention discloses a method for producing dimethyl sulfone from hydrogen sulfide. The method includes: (1) subjecting hydrogen sulfide and methyl alcohol to contacting to obtain a mixture containing dimethyl sulfide; (2) subjecting the mixture containing dimethyl sulfide to heat exchange with a heat exchange medium to obtain a cooled mixture and a heated heat exchange medium; (3) subjecting the cooled mixture to contact oxidation reaction with an oxidizing agent and titanium silicate molecular sieves to obtain a mixture containing dimethyl sulfone; optionally, (4) subjecting the mixture containing dimethyl sulfone to separation to obtain dimethyl sulfide and dimethyl sulfone low in dimethyl sulfide content; optionally, (5) cyclically feeding at least part of the separated dimethyl sulfide in the step (4) to the step (3). According to the method, continuous production of dimethyl sulfone from hydrogen sulfide is realized, high dimethyl sulfide conversion rate is realized, and the method is especially suitable for large-scale production.
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Paragraph 0117-0119; 0169-0171; 0193-0195; 0218-0220
(2018/12/05)
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- A hydrogen sulfide production by the method of the dimethyl sulfoxide (by machine translation)
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The invention discloses a method of hydrogen sulfide production dimethyl sulfoxide, including: (1) the hydrogen sulfide with methanol, containing the dimethyl sulfide mixture; (2) the mixture of the gas-liquid separation, to obtain the vapor stream and a liquid stream containing dimethyl sulfide, optionally a gas phase stream circulation into the step (1) in; (3) under the conditions of the oxidation reaction, the liquid phase stream and the oxidizing agent and the titanium-silicon is exposed to molecular sieves, containing the mixture of dimethyl sulfoxide; optionally, (4) containing dimethyl sulfoxide is separated from the mixture, to obtain the dimethyl sulfide; optionally, (5) the step (4) of the separated dimethyl sulfide circulation into the step (3) in. The method of continuous production of hydrogen sulfide as a raw material to dimethyl sulfoxide, can obtain higher of dimethyl sulfide conversion, is especially suitable for large-scale production of the occasions. (by machine translation)
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Paragraph 0118-0120; 0169-0171; 0192-0194; 0219-0221
(2018/12/02)
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- Catalytic Synthesis of Methylthiophenes
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The gas-phase reaction of dimethyl disulfide with thiophene over Co/HZSM-5 catalyst in a helium medium under atmospheric pressure at 250–350°C gave a mixture of mono-, di-, tri-, and tetramethylthiophenes with an overall selectivity of 94–96%.
- Mashkina,Khairulina
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p. 1794 - 1797
(2019/03/26)
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- A catalyst-free and additive-free method for the synthesis of benzothiazolethiones from: O -iodoanilines, DMSO and potassium sulfide
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Under catalyst-free and additive-free conditions, a novel, convenient, eco-friendly method for the synthesis of benzothiazolethiones has been developed. The three-component reaction of o-iodoanilines and K2S with DMSO proceeded smoothly and the corresponding benzothiazolethiones were obtained with good isolated yields. Meanwhile, this method could be used for the synthesis of thioureas from primary diamines. Furthermore, mechanism research showed that DMSO not only functioned as a carbon source, but also as a mild oxidant in this reaction.
- Zhu, Xiaoming,Li, Wenguang,Luo, Xiai,Deng, Guobo,Liang, Yun,Liu, Jianbing
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supporting information
p. 1970 - 1974
(2018/05/23)
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- Catalytic synthesis of dialkyl sulfides from dialkyl disulfides
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Dialkyl disulfides R2S2 where R = Me, Et, or Pr, both as individual compounds and as their mixtures, isolated from petroleum products can turn into alkanethiols and dialkyl sulfides under the action of catalysts having strong acid sites and medium-strength basic sites on their surface. In a helium atmosphere, the main conversion products are alkanethiols, while dialkyl sulfides form in low yield at a selectivity of no higher than 20%. A much higher dialkyl sulfide selectivity is attained in the reaction involving methanol. The most efficient catalyst for this reaction is alumina, with which the dialkyl sulfide selectivity is up to 99%.
- Mashkina,Khairulina
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p. 402 - 408
(2017/08/08)
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- Initiation in Photoredox C-H Functionalization Reactions. Is Dimsyl Anion a Key Ingredient?
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Previous studies have reported the arylation of unactivated arenes with ArX, base (KOtBu or NaOtBu), and an organic additive at high temperatures. Recently, we showed that this reaction proceeds in the absence of additives at rt but employs UV-vis light. However, details of mechanisms that can use a photoinduced base-promoted homolytic aromatic substitution reaction (photo-BHAS) have remained elusive until now. This work examines different mechanistic routes of the essential electron-transfer step (ET) of this reaction in order to identify a possible path for the formation of 1-adamantyl radicals from 1-haloadamantanes (initiation step). On the basis of photochemical and photophysical experiments and computational studies, we propose an unprecedented initiation step that could also be applied to other ET reactions performed in DMSO. For the first time, it is reported that dimsyl anion, formed from a strong base and DMSO (solvent), is responsible for inducing the initiation by a photo-BHAS process on alkyl halides.
- Budén, María E.,Bardagí, Javier I.,Puiatti, Marcelo,Rossi, Roberto A.
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p. 8325 - 8333
(2017/08/23)
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- Magnesium hydridotriphenylborate [Mg(thf)6][HBPh3]2: A versatile hydroboration catalyst
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Magnesium bis(hydridotriphenylborate), isolated as a solvent-separated ion pair [Mg(thf)6][HBPh3]2, effectively catalyzed the hydroboration of several unsaturated substrates including CO2.
- Mukherjee, Debabrata,Shirase, Satoru,Spaniol, Thomas P.,Mashima, Kazushi,Okuda, Jun
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supporting information
p. 13155 - 13158
(2016/11/09)
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- Catalytic reactions of dimethyl disulfide with thiophene and benzene
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The gas-phase reaction of dimethyl disulfide with thiophene proceeds under the action of acid catalysts under atmospheric pressure at 160-350°C and a residence time of τ = 0.6-21 s to form thioalkylation and alkylation products. Dimethyl disulfide reacts with benzene to form only alkylation products. Catalysts containing both strong protic and Lewis acid sites, as well as basic sites of moderate strength, are the most active ones.
- Mashkina,Khairulina
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- DIMETHYLSULFOXIDE PREPARATION METHOD
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A process for producing dimethyl sulfoxide, wherein said process comprises the following steps: (1) contacting hydrogen sulfide with methanol to produce a mixture containing dimethyl sulfide, and separating dimethyl sulfide from the mixture; and (2) in the presence or absence of a solvent, contacting dimethyl sulfide obtained in step (1) with at least one oxidant and a catalyst to produce a mixture containing dimethyl sulfoxide, said catalyst comprises at least one Ti—Si molecular sieve.
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Paragraph 0072; 0073; 0074; 0075; 0076-0085
(2015/10/28)
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- N-Imidazolylation of Sulfoximines from N-Cyano Sulfoximines, 1-Alkynes, and N-Sulfonyl Azides
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The rhodium-catalyzed N-imidazolylation of N-sulfonyl-1,2,3-triazoles with a variety of N-cyano sulfoximines has been developed for the synthesis of N-imidazolyl sulfoximines via elimination of molecular nitrogen. Copper-catalyzed [3+2] cycloaddition followed by rhodium-catalyzed N-imidazolylation from 1-alkynes, N-sulfonyl azides, and N-cyano sulfoximines is also demonstrated for the synthesis of N-imidazolyl sulfoximines in a one-pot procedure.
- Kim, Sanghyuck,Kim, Ji Eun,Lee, Jinsub,Lee, Phil Ho
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supporting information
p. 3707 - 3717
(2016/01/25)
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- Carbenoid-mediated nucleophilic "hydrolysis" of 2-(dichloromethylidene)-1,1,3,3-tetramethylindane with DMSO participation, affording access to one-sidedly overcrowded ketone and bromoalkene descendants
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2-(Dichloromethylidene)-1,1,3,3-tetramethylindane was " hydrolyzed" by solid KOH in DMSO as the solvent at ≥100 °C through an initial chlorine particle transfer to give a Cl,K-carbenoid. This short-lived intermediate disclosed its occurrence through a reversible proton transfer which competed with an oxygen transfer from DMSO that created dimethyl sulfide. The presumably resultant transitory ketene incorporated KOH to afford the potassium salt of 1,1,3,3-tetramethylindan-2-carboxylic acid (the product of a formal hydrolysis). The lithium salt of this key acid is able to acylate aryllithium compounds, furnishing one-sidedly overcrowded ketones along with the corresponding tertiary alcohols. The latter side-products (ca. 10%) were formed against a substantially increasing repulsive resistance, as testified through the diminished rotational mobility of their aryl groups. As a less troublesome further side-product, the dianion of the above key acid was recognized through carboxylation which afforded 1,1,3,3-tetramethylindan- 2,2-dicarboxylic acid. Brominative deoxygenation of the ketones furnished two one-sidedly overcrowded bromoalkenes. Some presently relevant properties of the above Cl,K-carbenoid are provided in Supporting Information File 1.
- Knorr, Rudolf,Menke, Thomas,Freudenreich, Johannes,Pires, Claudio
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p. 307 - 315
(2014/03/21)
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- Microorganisms for producing organic acids
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Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.
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Page/Page column
(2014/10/15)
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- Catalysis by desolvation: The catalytic prowess of SAM-dependent halide-alkylating enzymes
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In the biological fixation of halide ions, several enzymes have been found to catalyze alkyl transfer from S-adenosylmethionine to halide ions. It proves possible to measure the rates of reaction of the trimethylsulfonium ion with I-, Br-
- Lohman, Danielle C.,Edwards, David R.,Wolfenden, Richard
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supporting information
p. 14473 - 14475
(2013/10/22)
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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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- Selective reduction of organic compounds with Al- trifluoromethanesulfonyldiisobutylalane. Comparison of its reactivity with Al-methanesulfonyldiisobutylalane
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The new MPV type reagent, Al-trifluoromethanesulfonyldiisobutylalane (DIBAO3SCF3), has been prepared and its reducing characteristics in the reduction of selected organic compounds containing representative functional groups have been examined, and compared its reactivity with that of Al-methanesulfonyldiisobutylalane (DIBAO3SCH 3) in order to understand the fluorine-substituent effect on its reactivity. In general, the reactivity of DIBAO3SCF3 appears to be much higher than that of DIBAO3SCH3, apparently due to the acidity increase by the electron-withdrawing fluorine-substituent. The reagent reduced aldehydes and ketones readily, but showed a perfect selectivity in the reduction of α,β-unsaturated aldehydes and ketones to produce the corresponding allylic alcohols in an absolutely 100% purity. In addition, the reagent achieved the regioselective cleavage of phenyl-or/and alkyl-substituted epoxides to the less substituted alcohols in a perfect regioselectivity. Moreover, the reagent also showed an high stereoselectivity in the reduction of substituted cycloalkanones to produce the thermodynamically more stable alcohol epimers exclusively.
- Cha, Jin Soon
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experimental part
p. 219 - 224
(2011/11/06)
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- New method of dimethyl sulfi de synthesis
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The synthesis of dimethyl sulfide consists in the reaction of dimethyl disulfide with methanol in the presence of solid catalyst, aluminum γ-oxide. The yield of dimethyl sulfide grows with growing temperature, contact time, and content of methanol in the reaction mixture. At 350-400°C, molar ratio methanol-dimethyldisulfide 2.0-2.5, and total conversion of the reagents the yield of dimethyl sulfide reached 95 mol%. Pleiades Publishing, Ltd., 2011.
- Mashkina
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experimental part
p. 678 - 681
(2011/08/09)
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- Syntheses of 2-amino and 2-halothiazole derivatives as high-affinity metabotropic glutamate receptor subtype 5 ligands and potential radioligands for in vivo imaging
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The structure of the potent selective mGlu5 ligand, SP203 (1, 3-fluoro-5-[[2-(fluoromethyr)thiazol-4-yl]ethynyl]benzonitrile), was modified by replacing the 2-fluoromethyl substituent with an amino or halo substituent and by variation of substituents in the distal aromatic ring to provide a series of new high-affinity mGlu5 ligands. In this series, among the most potent ligands obtained, the 2-chloro-thiazoles 7a and 7b and the 2-fluorothiazole 10b showed subnanomolar mGlu5 affinity. 10b also displayed >10000-fold selectivity over all other metabotropic receptor subtypes plus a wide range of other receptors and binding sites. The 2-fluorothiazoles 10a and 10b were labeled using [18F]fluoride ion (t1/2 = 109.7 minin moderately high radiochemical yield to provide potential radioligands that may resist troublesome radiodefluorination during the imaging of brain mGlu 5 with position emission tomography. The iodo compound 9b has nanomolar affinity for mGlu5 and may also serve as a lead to a potential 123I-labeled ligand for imaging brain mGlu5 with single photon emission computed tomography.
- Siméon, Fabrice G.,Wendahl, Matthew T.,Pike, Victor W.
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scheme or table
p. 901 - 908
(2011/04/16)
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- Hydrogenation Catalyst, Particularly for Carbon Disulphide
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The present invention relates to a hydrogenation catalyst, particularly useful for the hydrogenation of carbon disulphide (CS2) to form methyl mercaptan (CH3SH), and to a preparation method thereof. The present invention also relates to a method for continuously preparing methyl mercaptan by the catalytic hydrogenation of carbon disulphide, with a carbon disulphide conversion rate of 100%, and a methyl mercaptan selectivity of 100%.
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Page/Page column 4-5
(2011/09/20)
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- Concerning the deprotonation of the trimethylsulfonium ion by the dimethylsulfinyl anion
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As shown by deuterium labelling experiments, the deprotonation of the trimethylsulfonium ion (1) by the dimsyl anion (8) is accompanied by extensive hydrogen exchange. This cannot be explained by an acid-base equilibrium between the trimethylsulfonium ion (1) and the dimsyl anion (8) on one side and dimethylsulfonium methylide (2) and DMSO on the other side, because for thermodynamic reasons this process is irreversible due to the limited life-time of 2. Therefore, the isotopic exchange that accompanies the deprotonation is an indicator of a more complex deprotonation process. It is suggested that in a kinetically controlled reaction, a proton of 1 is transferred to the O-atom of 8 rather than to the carbanionic centre. This means that instead of DMSO, its tautomer, hydroxy-methylsulfonium methylide (10), is obtained in the deprotonation process. Similarly, in the acid-base interaction between DMSO and its conjugate base 8, the formation of the DMSO tautomer 10 is kinetically favoured. The intermediate 10 produced in this way transfers a DMSO-derived proton to 1 when it intervenes in the back reaction 10 + 2 → 8 + 1. An alternative mechanism based on methyl group exchange between 1 and 8 could be excluded by a 13C-labelling experiment. The hydrogen exchange according to the suggested scenario is taking place in competition with the reaction of dimethylsulfonium methylide (2) with electrophilic substrates. This explains the different degrees of isotopic exchange when compounds of different electrophilicities are used to scavenge 2 from the deprotonation-hydrogen distribution equilibria.
- Haiss, Peter,Zeller, Klaus-Peter
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body text
p. 7748 - 7754
(2011/12/03)
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- Mild and efficient deoxygenation of sulfoxides to sulfides using HFCL 4/KBH4 system
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HfCl4/KBH4 was found to be a facile, efficient, convenient, and chemoselective system for the deoxygenation of dialkyl, diaryl, and aryl alkyl sulfoxides, especially for the reduction of dibenzyl sulfoxide to the corresponding sulfides under mild conditions. In addition, the HfCl 4/KBH4 system could be used in reduction of some other sulfur-bearing substrates to the corresponding sulfides, such as 2,2'-dibenzothiazolyl disulfide, but this reducing system could not reduce sulfolane, diphenyl sulfone, p-toluenesulfonic acid, and p-toluenesulfonyl chloride to their corresponding thiophenols. Copyright
- Zhang, Jianghua,Gao, Xinqin,Zhang, Chengyi,Zhang, Cheng,Luan, Jiming,Zhao, Defeng
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experimental part
p. 1794 - 1801
(2010/07/14)
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- Selective reduction of organic compounds with Al- methanesulfonyldiisobutylalane
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The new MPV type reagent, Al-methanesulfonyldiisobutylalane (DIBAO 3SCH3), has been prepared and its reducing characteristics in the reduction of selected organic compounds containing representative functional groups have been examined in order to find out a new reducing system with high selectivity in organic synthesis. In general, the reagent is extremely mild, showing only reactivity toward aldehydes, ketones and epoxides. The reagent exhibits a unique reducing applicability in organic synthesis. Thus, the reagent can achieve a clean 1,2-reduction of α,β-unsaturated aldehydes and ketones to produce the corresponding allylic alcohols in 100% purity. In addition, the reagent shows an excellent regioselectivity in the ring-opening reaction of epoxides. Finally, DIBAO3SCH3 shows a high stereo-selectivity in the reduction of cyclic ketones to produce the thermodynamically more stable epimers exclusively.
- Cha, Jin Soon,Noh, Minyeong
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experimental part
p. 840 - 844
(2010/10/21)
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- Dimethyl disulfide conversion into dimethyl sulfide in the presence of sulfidized catalysts
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The conversion of dimethyl disulfide in the presence of various supported sulfidized metal-containing catalysts at atmospheric pressure and T = 150-350°C was studied. Sulfidized transition metals supported onto aluminum oxide were more active than catalysts based on a carbon support, silicon dioxide, amorphous aluminosilicate, and zeolite ZSM-5. The most active catalyst was 10% Co/Al2O3 prepared with the use of cobalt acetate as an active component precursor and treated with a mixture of hydrogen sulfide with hydrogen at T = 400°C. From kinetic data, it follows that all of the reaction products were formed simultaneously at a temperature of 200°C, whereas a consecutive reaction scheme took place at higher temperatures. In the presence of a sulfidized alumina-cobalt catalyst, the output of dimethyl sulfide was higher than that reached with the use of other well-known catalysts.
- Mashkina,Khairulina
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experimental part
p. 724 - 730
(2011/02/16)
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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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body text
p. 7793 - 7798
(2010/12/20)
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- Activity of zeolites in dimethyl sulfide synthesis
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Dimethyl disulfide conversion into dimethyl sulfide over various zeolites in an inert medium at atmospheric pressure and T = 190-330°C is reported. A significant activity in dimethyl sulfide formation is shown by the decationized zeolites HNaY and HZSM-5, whose surface has strong protonic and nonprotonic acid sites. Cobalt-containing faujasite is more active than HNaY, and the activity of CoHZSM-5 is comparable with the activity of its decationized counterpart.
- Mashkina,Khairulina
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experimental part
p. 579 - 583
(2011/01/09)
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- From 2,3-, 2,6-, 3,4- and 4,6-dichloroquinolines to isomeric chloroquinolinesulfonyl chlorides
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The action of sodium methanethiolate (in boiling DMF) on x,y-dichloroquinolines (1) (x=3 or 6, y=2 or 4) occured via chlorine ipso-substitution followed by methanethiolato-S-demethylation to yield x,y-quinolinedithiolates 2A which were: i) subjected to S-
- Marciniec, Krzysztof,Maslankiewicz, Andrzej
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experimental part
p. 305 - 316
(2010/08/20)
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- Vapor generation of inorganic anionic species after aqueous phase alkylation with trialkyloxonium tetrafluoroborates
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Aqueous phase reaction of trialkyloxonium tetrafluoroborates, R 3O+BF4- (R=Me, Et) has been tested in the alkylation of simple inorganic anionic substrates such as halogen ions, cyanide, thiocyanate, sulphide an
- D'Ulivo, Alessandro,Pagliano, Enea,Onor, Massimo,Pitzalis, Emanuela,Zamboni, Roberto
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experimental part
p. 6399 - 6406
(2010/04/06)
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- Formation of DMSO and DMF radicals with minute amounts of base
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So far overlooked DMSO and DMF form long-lived radicals in the presence of small amounts of bases, DMF radicals being less stable than DMSO radicals. In solvent mixtures, the presence of DMSO prolonged the lifetime of DMF radicals. The occurrence of radic
- ?pstad, Christer L.,Mel?, Thor-Bernt,Sliwka, Hans-Richard,Partali, Vassilia
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body text
p. 7616 - 7619
(2009/12/04)
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