- Gas-phase reactions of O(3P) atoms with methanethiol, ethanethiol, methyl sulfide, and dimethyl disulfide. 2. Reaction products and mechanisms
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In conjunction with the determinations of the rate constants of reactions of the ground-state oxygen atoms, O(3P), with methanethiol, ethanethiol, methyl sulfide, and dimethyl disulfide described in the preceding paper,3 a parallel study was carried out of the products and mechanisms of the same reactions at 300 K. Oxygen atoms were generated by the mercury-photosensitized decomposition of N2O, used in large excess, and the recovered products were analyzed by gas chromatography. The total pressure was varied from 300 to 1200 torr. Nitrogen formed in the photosensitized decomposition of N2O provided a direct measure of the number of O atoms generated and allowed determination of the yields of some of the products per oxygen atom reacting with the sulfur organic compounds. From a detailed analysis of the experimental results obtained with single sulfur organics and their mixtures, it is possible to derive substantial quantitative information on the reaction mechanisms. The postulated overall reaction mechanisms include some novel features common to the thiols, sulfide, and disulfide studied, which provide a simple explanation for some unexpected experimental trends observed.
- Cvetanovic,Singleton,Irwin
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- Kinetics and Mechanism of the Autoxidation of 2-Aminoethanethiol and Ethanethiol Catalyzed by Cobalt(II) 4,4',4'',4'''-Tetrasulfophthalocyanine in Aqueous Solution
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The kinetics of autoxidation of 2-aminoethanethiol to 2-aminoethyl disulfide and ethanethiol to ethyl disulfide as catalyzed by cobalt(II) 4,4',4'',4'''-tetrasulfophthalocyanine (CoIITSP) were investigated.The following general rate law found to hold for both substrates over the pH range 8.8-13.5: ν = -d->/dt = kobsdT->.Evidence for a mechanism that proceeds via a dimeric catalytic center that is bridged by the RS- anion has been obtained.In the proposed mechanism, electron transfer from the Co(II) metal center to bound dioxygen was considered to the rate-determining step.Hydrogen peroxide and mercaptan radical were identified as reaction intermediates in the autoxidation of both substrates.These intermediates react further to produce the correponding disulfide, RSSR. as the final product of the autoxidation. kobsd was found to be of the following general form: kobsd = (k31K21 + (k32K22K'1/aH+) + (k33K23K'1K'2/aH+2))/1/aH+) + (K'1K'2/aH+2))(1 + (aH+/K'a12))>, where k3i and K2i are the rate constants for the electron transfer and the equilibrium constants for substrate complexation of the ith catalytic center, respectively, K'1 and K'2 are the apparent acid dissociation constants of the pyrrole groups of CoIITSP-RS--CoIITSP and CoIITSP-RS--CoIITSP-, respectively, and K'a1 is the apparent acid dissociation constant of RCH2CH2SH.
- Leung, Ping-Sang K.,Hoffmann, Michael R.
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- Universal Anticancer Cu(DTC)2 Discriminates between Thiols and Zinc(II) Thiolates Oxidatively
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Aerobic organisms must rely on abundant intracellular thiols to reductively protect various vital functional units, especially ubiquitous zinc(II) thiolate sites of proteins, from deleterious oxidations resulting from oxidizing environments. Disclosed here is the first well-defined model study for reactions between zinc(II) thiolate complexes and copper(II) complexes. Among all the studied ligands of copper(II), diethyldithiocarbamate (DTC) displays a unique redox-tuning ability that enables copper(II) to resist the reduction by thiols while retaining its ability to oxidize zinc(II) thiolates to form disulfides. This work proves for the first time that it is possible to develop oxidants to discriminate between thiols and zinc(II) thiolates, alluding to a new chemical principle for how oxidants, especially universal anticancer Cu(DTC)2, might circumvent the intracellular reductive defense around certain zinc(II) thiolate sites of proteins to kill malignant cells.
- Xu, Luyan,Xu, Jialin,Zhu, Jingwei,Yao, Zijian,Yu, Na,Deng, Wei,Wang, Yu,Lin, Bo-Lin
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- Graphite oxide: A selective and highly efficient oxidant of thiols and sulfides
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The selective oxidation of thiols to disulfides and sulfides to sulfoxides using graphite oxide (GO), a heterogeneous carbocatalyst obtained from low cost, commercial starting materials is described. The aforementioned oxidation reactions were found to proceed rapidly (as short as 10 min in some cases) and in good yield (51-100%) (19 examples). No over-oxidation of the substrates was observed, and GO's heterogeneous nature facilitated isolation and purification of the target products.
- Dreyer, Daniel R.,Jia, Hong-Peng,Todd, Alexander D.,Geng, Jianxin,Bielawski, Christopher W.
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- Catalytic oxidation of thiols to disulfides with vanadyl acetylacetonate (VO(ACAC)2)
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Catalytic amounts of VO(acac)2 coupled with t-butylhydroperoxide chemoselectively oxidizes thiols to disulfides under mild reaction conditions and is generally useful for a wide variety of thiols.
- Raghavan,Rajender,Joseph,Rasheed
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- An efficient and mild cleavage of thiol acetate with clayfen in the absence of solvent
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The disulphides are synthesised through the mild cleavage of thiol acetate with clayfen in the absence of solvent.
- Meshram, Harshadas M.
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- C-S Bond Cleavage, Redox Reactions, and Dioxygen Activation by Nonheme Dicobalt(II) Complexes
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Synthesis and reactivity of a series of thiolate/thiocarboxylate bridged dicobalt(II) complexes were investigated in comparison with their carboxylate bridged analogues bearing free thiol/hydroxyl groups. Upon one-electron oxidation, complexes [Co2(N-Et-HPTB)(μ-SR1)](BF4)2 (R1 = Ph, 1a; Et, 1b; Py, 1c) and [Co2(N-Et-HPTB)(μ-SCOR2)](BF4)2 (R2 = Ph, 2a; Me, 2b) yielded [Co2(N-Et-HPTB)(DMF)2](BF4)3 (6) (DMF = dimethylformamide) along with the corresponding disulfides (where N-Et-HPTB is the anion of N,N,N′,N′-tetrakis[2-(1-ethylbenzimidazolyl)]-2-hydroxy-1,3-diaminopropane). Unlike the inertness of carboxylate bridged complexes [Co2(N-Et-HPTB)(μ-O2C-R3-SH)](BF4)2 (R3 = Ph, 3a; CH2CH2, 3b) and [Co2(N-Et-HPTB)(μ-O2CR4)](BF4)2 (R4 = Ph, 4a; Me, 4b; CH2CH2CH2OH, 5) toward O2, the bridging ethanethiolate in 1b was oxidized to yield a sulfinate bridged complex, [Co2(N-Et-HPTB)(μ-O2SEt)](BF4)2 (10). Detailed investigation of the synthetic aspects of 1a-1c led to the discovery of a C-S bond cleavage reaction and yielded the dicobalt(II) complexes [Co2(N-Et-HPTB)(SH)(H2O)](BF4)2 (8a), [Co2(N-CH2Py-HPTB)(SH)(H2O)](BF4)2 (8b) (where N-CH2Py-HPTB is the anion of N,N,N′,N′-tetrakis[2-(1-picolylbenzimidazolyl)]-2-hydroxy-1,3-diaminopropane)), and [Co2(N-Et-HPTB)(μ-S)](BF4) (9). Both 8a and 8b feature nonheme dinuclear Co(II) units containing a terminal hydrosulfide. The present study thus reports comparative redox reactions for a rare class of 16 dicobalt(II) complexes and introduces a selective synthetic strategy for the synthesis of unprecedented dicobalt(II) complexes featuring only one terminal hydrosulfide.
- Jana, Manish,Majumdar, Amit
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- Aerobic oxidation of thioglycol catalysed by metallophthalocyanine in an organic-inorganic hybrid vesicle “cerasome”
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A molecular assembly of a hydrophobized metallophthalocyanine derivative embedded in a cerasome, an organic–inorganic hybrid vesicle with a lipid bilayer and silica surface, was a potent catalyst for aerobic oxidation of thioglycol. The catalytic activity was higher than those in hexadecyl 2-hydroxy-3-chloropropyl phosphate vesicles, sodium dodecylsulfate micelles, ethanol, and benzene.
- Hisaeda, Yoshio,Kikuchi, Jun-ichi,Sasaki, Yoshihiro,Song, Xi-Ming,Wu, Qiuhua,Yasuhara, Kazuma,Zhang, Dan,Zhang, Guolin,Zhang, Li
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- Oxidative dimerization of thiols to disulfide using recyclable magnetic nanoparticles
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Abstract: Dimerization of thiol groups to disulfide is an important transformation in chemical processes. In this study, magnetic ion exchanged Montmorillonite-k10 was synthesized and characterized using FTIR, X-ray diffraction and scanning electron microscope techniques. Then, the application of the synthesized catalyst as an efficient oxidizing agent was evaluated in oxidative dimerization of different thiols to corresponding disulfides under optimal reaction conditions. The reaction was easily performed with aromatic, aliphatic and heterocyclic thiols. The magnetic catalyst was easily recovered by applying an external magnet and, further, was reused in successive reactions. Graphical Abstract: [Figure not available: see fulltext.]
- Masnabadi, Nasrin,Ghasemi, Mohammad Hadi,Beyki, Mostafa Hossein,Sadeghinia, Mohammad
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- Synthesis, structure and DFT study of asymmetrical NHC complexes of cymantrene derivatives and their application in the dehydrogenative dimerization reaction of thiols
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Asymmetrical NHC complexes of cymantrene and methylcymantrene have been synthesised through the photochemical substitution of carbonyl ligands in the presence of the imidazol-2-ylidene salts. The carbene substituents have been varied between compact (L1) and bulky (L2 and L3) substituents to produce an array of differently sized carbene ligands. The solid state crystal structures of three of the complexes confirmed the bonding pattern of the ligand towards available metal centres and an in-depth DFT study provided insight into electronic and steric aspects. Application of the Extended Transition State coupled with Natural Orbitals for Chemical Valence (ETS-NOCV) energy decomposition technique indicated various NOCV channels for each Mn–L bond (L?=?3-ethyl-1-methylimidazolylidene carbene, triphenylphosphine or acetonitrile), describing the density and energy changes of specific (σ and π) attributes of each bond. N-heterocyclic carbenes of cymantrene derivatives and their triphenylphosphine-substituted analogue are equivalent σ-donors, with 53% and 56%, respectively, of the total binding energy originating from σ-donation. However, NHC complexes show considerably less π character in the metal-carbene bond. Hydrogen interactions in the NHC complexes were also identified in the ETS-NOCV calculations and provided quantification of the hydrogen interactions witnessed in the solid state structures. Calculated Wiberg bond indices, bond dissociation enthalpies, percentage buried volumes and percentage sigma and pi-bonding characteristics quantified the bonding and electronic aspects of the ligand-metal interactions within the complex.
- Fraser, Roan,van Rooyen, Petrus H.,de Lange, Jurgens,Cukrowski, Ignacy,Landman, Marilé
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- Heterogeneous photocatalytic degradation of disulfoton in aqueous TiO 2 suspensions: Parameter and reaction pathway investigations
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The photocatalytic degradation of organophosphorus insecticide disulfoton is investigated by having titanium dioxide (TiO2) as a photocatalyst. About 99% of disulfoton is degraded after UV irradiation for 90 min. The effects of the solution pH, catalyst dosage, light intensity, and inorganic ions on the photocatalytic degradation of disulfoton are also investigated, as well as the reaction intermediates which are formed during the treatment. Eight intermediates have been identified and characterized through a mass spectra analysis, giving insight into the early steps of the degradation process. To the best of our knowledge, this is the first study reporting the degradation pathways of disulfoton. The results suggest that possible transformation pathways may involve in either direct electron or hole transfer to the organic substrate. The photodegradation of disulfoton by UV/TiO2 exhibits pseudo-first-order reaction kinetics and a reaction quantum yield of 0.267. The electrical energy consumption per order of magnitude for photocatalytic degradation of disulfoton is 85 kWh/(m3 order).
- Chen, Ming-Hung,Chen, Chiing-Chang,Wu, Ren-Jang,Lu, Chung-Shin
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- PHOTOCHEMISTRY AND ELECTRONIC STRUCTURE OF THE ( eta 5-C5H5)2TiS5 COMPLEX.
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The Cp//2TiS//5 complex (Cp equals eta **5-C//5H//5) is photochemically quite unreactive. The complex does not react with acetylenes, CO, phosphites, or amines at either high- or low-energy irradiation wavelengths. The complex does react with halocarbons to afford Cp//2TiX//2 (X equals halide) and it reacts with organic disulfides (RSSR) to give Cp//2Ti(SR)//2 complexes. However, the quantum yields for these reactions are quite low (e. g. , phi //3//6//6 equals 6 multiplied by 10** minus **3 for the reaction with CCl//4; phi //3//6//6 equals 2 multiplied by 10** minus **3 for the reaction with PhSSPh). Flash photolysis of the complex produces a transient that decays by first-order kinetics (k equals 2 multiplied by 10**4 s** minus **1). The transient is proposed to be a species in which a single Ti-S bond has been cleaved. Rapid reformation of the Ti-S bond is suggested to be the reason for the photochemical inertness of the complex.
- Bruce,Bruce,Tyler
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- Nature of 2?/1?* Three-Electron-Bonded Chlorine Adducts to Sulfoxides
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Reaction of sulfoxide radical cations, R2SO.+, with chloride ions in acidic aqueous solutions (pH * electron.The same species is formed upon oxidation of sulfoxides by Cl2*, although only with relatively low rate constants.The measured λmax are 390, 400, and 410 nm for the R2SO...Cl species with R = Me, Et, and n-Pr, respectively.Equilibrium constants for R2SO.+ + Cl- R2SO...Cl have been determined to be 560, 600, and 575 M-1, for the same respective series of species (error limit +/- 20percent).It is considered that our three-electron-bonded species is identical with an electronically not further specified chlorine-atom adduct to sulfoxide, R2SO(Cl)., observed earlier in sulfoxide-containing solutions of carbon tetrachloride and dichloromethane.The R2SO...Cl exhibit oxidizing properties and are shown to oxidize, for example organic sulfides and disulfides (rate constants on the order of 108 M-1 s-1) or SCN- (rate constants on the order of 109 M-1 s-1).The optical and kinetic results are discussed in light of the electronic properties of the radical species.
- Kishore, Kamal,Asmus, Klaus-Dieter
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- A CONVENIENT REDUCTION OF FUNCTIONALIZED POLYCYCLIC AROMATICS INTO PARENT HYDROCARBONS
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Polycyclic aromatics with various functional group (e.g.OH, OR, SR, and halogen) were easily defunctionalized by aluminum chloride and ethanethiol to give parent aromatics in high yields under mild conditions.This reaction proceeds through sulfide as the intermediate, hence it is also useful for the synthesis of sulfides of polycyclic aromatics.
- Node, Manabu,Nishide, Kiyoharu,Ohta, Keiichiro,Fujita, Eiichi
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- Nitric Acid Mediated Oxidative Transformation of Thiols to Disulfides
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Oxidation of thiols to disulfides are reported using nitric acid/methylene chloride. Environmentally benign, economically convenient and simple reaction condition represents an attractive alternative to the existing approaches on both the laboratory and the industrial scale.
- Misra, Anup Kumar,Agnihotri, Geetanjali
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- Reaction of Mono- and Dihaloalkanes with Mixed Solutions of Chalcogens in Alkaline Reductive Systems
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Sufur-selenium, sulfur-tellurium, selenium-tellurium, and sulfur-selenium-tellurium mixtures readily dissolve in the hydrazine hydrate-alkali system to form chalcogenide anions. Alkylation of the latter with ethyl bromide results in preferential formation
- Deryagina,Grabel'nykh,Mamaseva
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- Hydrolysis of Phorate Using Simulated Environmental Conditions: Rates, Mechanisms, and Product Analysis
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The hydrolysis of phorate, an organophosphorus pesticide, was studied under simulated environmental conditions. Several metal oxides (aluminum hydroxide, hematite, goethite, and ferrihydrite) were chosen to represent the solid phase in natural aquatic sys
- Hong, Feng,Pehkonen, Simo
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- First experimental evidence for the formation of a silicate anion by intramolecular addition of a persulfoxide to a trimethylsiloxy group
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The photooxidation of an α-trimethylsiloxysulfide has been studied. The reaction generates a persulfoxide which can be trapped by diphenylsulfoxide, decompose to generate triplet oxygen and substrate, or rearrange to a silicate product via a silicate intermediate.
- Clennan, Edward L.,Dillon, David L.
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- Oxidation of diethyl disulfide with atmospheric oxygen in the presence of 1,3-dimethylimidazolium dimethyl phosphate
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Oxidation of diethyl disulfide with atmospheric oxygen at 363 К in the presence of 1,3-dimethylimidazolium dimethyl phosphate is described. On the basis of the 1Н, 31Р, and 13С NMR data, it is shown that oxidation of diethyl disulfide results in ethyl sulfonates. Formation of ethyl alcohol, which is a product of a side reaction of ethyl sulfonate hydrolysis, probably, catalyzed by the 1,3-dimethylimidazolium cation, was detected using HPLC and 1Н and 13С NMR.
- Krivoborodov, E. G.,Mezhuev, Ya. O.,Novikova, E. P.,Zanin, A. A.
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- Aggregation of PMe3-stabilized molybdenum sulfides and the catalytic dehydrogenation of H2S
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The reactivity of [MoS4]2- (1) toward PMe3 was explored in the presence and absence of proton donors. Whereas MeCN solutions of (Et4N)2[MOS4] and PMe3 are stable, in the presence of H2S such solutions catalyze formation of H2 and SPMe3. Addition of NH4+ to such solutions afforded MoS2(PMe3)4 (2), which can be prepared directly from (NH4)2[1]. Compound 2 is reactive toward thiols via a process proposed to involve the initial dissociation of one PMe3 ligand, a hypothesis supported by the relative inertness of trans-MoS2(dmpe)2. Benzene solutions of 2 react with EtSH to give Mo2(μ-S)(μ-SH)(PMe3)4(SEt)3 (3Et). Analogous reactions with thiocresol (MeC6H4SH) and H2S gave Mo2(μ-S)(μ-SH)(PMe3)4(SR)3 (R = tol, H). Crystallographic analyses of 3Et, 3H, and 3tol indicate dinuclear species with seven terminal ligands and a Mo2(μ-SR)(μ-S) core (rMo-Mo = 2.748(1) A). From reaction mixtures leading to 3Et from 2, we obtained the intermediate Mo2IV(μ-S)2(SEt)4 (PMe3)2 (4), an edge-shared bis(trigonal pyramidal) structure. Compounds 3H and 3Et react further with H2S to give Mo4(μ2-S)4(μ3-S) 2(PMe3)6(SH)2 (5H) and Mo4(μ2-S)4(μ3-S) 2(PMe3)6(SEt)2 (5Et), respectively. Analogously, W4(μ2-S)4(μ3-S) 2(PMe3)6(SH)2 was synthesized from a methanol solution of (NH4)2WS4 with H2S and PMe3. A highly accurate crystallographic analysis of (NH4)2MoS4 (R1 = 0.0193) indicates several weak NH···S interactions.
- Schwarz, Daniel E.,Rauchfuss, Thomas B.,Wilson, Scott R.
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- Rapid and efficient synthesis of symmetrical alkyl disulfides under phase transfer conditions
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A one-pot, rapid and general method for the synthesis of symmetrical disulfides based on reaction of sulfur with sodium sulfide in the presence of didecyldimethylammonium bromide (DDAB) as a phase transfer catalyst is reported. Reaction with a variety of alkyl halides, at room temperature, afforded the disulfides in good to excellent isolated yields in a short time.
- Sonavane, Sachin U.,Chidambaram, Mandan,Almog, Joseph,Sasson, Yoel
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- A new application of N,N′-dibromo-N,N′-1,2-ethanediylbis(p- toluenesulfonamide) as selective and efficient reagent for the oxidation of various thiols to disulfides
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An efficient method for oxidation of thiol to their corresponding disulfides in high yields with N,N′-Dibromo-N,N′-1,2-ethanediyl bis (p-toluensulphonamide) in dichloromethane at room temperature is described. Copyright Taylor & Francis Inc.
- Khazaei, Ardeshir,Rostami, Amin
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- METHOD FOR OXIDATION OF SULFUR-CONTAINING COMPOUNDS
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Various embodiments disclosed relate to a method of oxidizing sulfur-containing compounds. The method involves contacting a sulfur-containing compound with a helmet phthalocyaninato-type catalyst in the presence of an oxidant. The present invention also provides a method of removing undesired sulfur-containing compounds from a fluid, such as natural gas, crude oil or an aqueous waste stream.
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Paragraph 0137-0140; 0143
(2021/10/30)
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- Preparation method of diethyl disulfide
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The invention relates to a preparation method of diethyl disulfide, comprising the following steps: using sodium sulfide, sulfur and diethyl sulfate as raw materials, carrying out stirring reaction at60-70 DEG C for 3-5 hours under the action of a phase transfer catalyst, and carrying out after-treatment on the reaction solution after the reaction is finished. According to the method, diethyl sulfate is used as an ethylation reagent, the cost is low, the reaction is easy to operate, the production period is short, and the ethyl utilization rate is high.
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Paragraph 0010; 0013-0015
(2020/06/02)
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- Mechanism of electrochemical reduction of 5-thio derivatives of 2(5H)-furanone
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The anionoid elimination of the substituent from position 5 of the lactone ring is the predominant pathway of electrochemical reduction of 5-arylsulfanyl- and 5-arylsulfonyl-3,4-dichloro-2(5H)-furanones in acetonitrile. The contribution of the competing elimination of the chloride ion increases on going to 3,4-dichloro-5-ethylsulfanyl-2(5H)-furanone. An experimental criterion based on the morphology of cyclic voltammograms was proposed for identification of a particular pathway of electroreduction of 2(5H)-furanone derivatives.
- Latypova,Chmutova,Kurbangalieva,Yanilkin
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p. 313 - 327
(2019/04/25)
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- An Organodiselenide with Dual Mimic Function of Sulfhydryl Oxidases and Glutathione Peroxidases: Aerial Oxidation of Organothiols to Organodisulfides
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A novel organodiselenide, which mimics sulfhydryl oxidases and glutathione peroxidase (GPx) enzymes for oxidation of thiols by oxygen and hydrogen peroxide, respectively, into disulfides has been presented. The developed catalyst oxidizes an array of organothiols into respective disulfides in practical yields by using aerial O2 to avoid any reagents/additives, base, and light source. The synthesized diselenide also catalyzes the reduction of hydrogen peroxide into water by following the GPx enzymatic catalytic cycle with a reduction rate of 49.65 ± 3.7 μM·min-1.
- Rathore, Vandana,Upadhyay, Aditya,Kumar, Sangit
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supporting information
p. 6274 - 6278
(2018/10/05)
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- Destruction of chemical warfare agent simulants by air and moisture stable metal NHC complexes
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The cooperative effect of both NHC and metal centre has been found to destroy chemical warfare agent (CWA) simulants. Choice of both the metal and NHC is key to these transformations as simple, monodentate N-heterocyclic carbenes in combination with silver or vanadium can promote stoichiometric destruction, whilst bidentate, aryloxide-tethered NHC complexes of silver and alkali metals promote breakdown under mild heating. Iron-NHC complexes generated in situ are competent catalysts for the destruction of each of the three targetted CWA simulants.
- Weetman, Catherine,Notman, Stuart,Arnold, Polly L.
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supporting information
p. 2568 - 2574
(2018/02/28)
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- Europhtal (8020) efficiently catalyzes the aerobic oxidation of in situ generated thiols to symmetric disulfides (disulfanes)
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Efficient, odorless and scalable synthetic protocols have been introduced for the preparation of symmetric alkyl disulfides by treatment of the corresponding organic halides with thiourea and NaHCO3in the presence of commercially available Europhtal catalyst (8020) in both H2O and poly ethylene glycol (PEG-200) media at 80–90 °C. Structurally diverse primary, secondary, allylic and benzylic halides were examined successfully whereas, the result with tert-butyl bromide was not satisfactory. Also, another procedure has been introduced for achieving symmetric aryl disulfides in high yields by reacting aryl halides, thiourea and NaHCO3in PEG-200 at 115–120 °C using CuI along with Europhtal catalysts. The results showed that the aerobic oxidation of in situ generated thiols proceeded efficiently in the presence of Europhtal catalyst giving the symmetric disulfide without contamination by symmetric sulfide side-product.
- Abbasi, Mohammad,Sabet, Askar,Sabet, Askar
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- Synthesis and in vitro biological evaluation of thiosulfinate derivatives for the treatment of human multidrug-resistant breast cancer
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Organosulfur compounds derived from Allium vegetables have long been recognized for various therapeutic effects, including anticancer activity. Allicin, one of the main biologically active components of garlic, shows promise as an anticancer agent; however, instability makes it unsuitable for clinical application. The aim of this study was to investigate the effect of stabilized allicin derivatives on human breast cancer cells in vitro. In this study, a total of 22 stabilized thiosulfinate derivatives were synthesized and screened for their in vitro antiproliferative activities against drug-sensitive (MCF-7) and multidrug-resistant (MCF-7/Dx) human adenocarcinoma breast cancer cells. Assays for cell death, apoptosis, cell cycle progression and mitochondrial bioenergetic function were performed. Seven compounds (4b, 7b, 8b, 13b, 14b, 15b and 18b) showed greater antiproliferative activity against MCF-7/Dx cells than allicin. These compounds were also selective towards multidrug-resistant (MDR) cells, a consequence attributed to collateral sensitivity. Among them, 13b exhibited the greatest anticancer activity in both MCF-7/Dx and MCF-7 cells, with IC50 values of 18.54±0.24 and 46.50±1.98 μmol/L, respectively. 13b altered cellular morphology and arrested the cell cycle at the G2/M phase. Additionally, 13b dose-dependently induced apoptosis, and inhibited cellular mitochondrial respiration in cells at rest and under stress. MDR presents a significant obstacle to the successful treatment of cancer clinically. These results demonstrate that thiosulfinate derivatives have potential as novel anticancer agents and may offer new therapeutic strategies for the treatment of chemoresistant cancers.
- Roseblade, Ariane,Ung, Alison,Bebawy, Mary
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p. 1353 - 1368
(2017/10/10)
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- Dicationic Thiolate-Bridged Diruthenium Complexes for Catalytic Oxidation of Molecular Dihydrogen
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Dicationic thiolate-bridged diruthenium complexes bearing sterically bulky alkane substituents on the thiolate ligands such as [Cp?Ru(μ-SiPr)2Ru(OH2)Cp?](OTf)2 have been found to work as effective catalysts toward oxidation of molecular dihydrogen into protons and electrons in protic solvents such as water and methanol. DFT calculations indicate that the sterically bulky alkane substituent in the complex plays an important role in facilitating the reaction step of the coordination of molecular dihydrogen.
- Yuki, Masahiro,Sakata, Ken,Nakajima, Kazunari,Kikuchi, Syoma,Sekine, Shinobu,Kawai, Hiroyuki,Nishibayashi, Yoshiaki
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supporting information
p. 4499 - 4506
(2017/12/05)
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- A two in one approach: Renewable support and enhanced catalysis for sweetening using chicken feather bound cobalt(II) phthalocyanine under alkali free environment
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Poultry waste chicken feathers, an inexpensive and abundantly available material has been used as a renewable support for immobilizing a cobalt phthalocyanine catalyst. The synthesized heterogeneous cobalt(ii) phthalocyanine catalyst was used for the aerobic oxidation of mercaptans to the corresponding disulfides using ultrasonic irradiation under alkali free conditions. The significantly higher catalytic activity of the heterogeneous catalyst as compared to a homogeneous one can be attributed to the synergistic effect of the support matrix. In addition, the catalyst could easily be recovered and recycled for several runs without loss of activity, which makes the process greener and more cost-effective.
- Chauhan, Deepak K.,Patnam, Padma L.,Ganguly, Sudip K.,Jain, Suman L.
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p. 51983 - 51988
(2016/06/13)
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- For preparing high-purity diethyla dithioether method of
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The invention relates to a method for preparing high-purity diethyl disulfide. The method comprises the following steps: mixing an ethanethiol-enriched petrochemical raw material with NaOH solution in a volume ratio of (1:1)-(5:1), and reacting for 1-30 minutes at 25-45 DEG C to prepare a sodium mercaptide-containing alkaline solution; adding cobalt phthalocyanine catalysts and an oxidant in the sodium mercaptide-containing alkaline solution, carrying out catalytic oxidation at 35-40 DEG C, and reacting for 1-8 hours to obtain a disulphide mixture; primarily distilling the disulphide mixture to obtain a disulphide crude product; rectifying and purifying the disulphide crude product to obtain the high-purity diethyl disulfide finished product. The method disclosed by the invention has the following beneficial effects that the production cost of diethyl disulfide is reduced, the production process is simplified, and the three-waste discharge and environmental pollution during the preparation process for the diethyl disulfide are reduced.
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Paragraph 0019-0025
(2017/04/07)
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- PREPARATION OF SYMMETRICAL AND ASYMMETRICAL DISULPHIDES BY REACTIVE DISTILLATION OF MIXTURES OF DISULPHIDES
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The invention relates to a process for the preparation of symmetrical or asymmetrical dialkyl disulphides by involving at least one mixture of symmetrical and/or asymmetrical dialkyl disulphides in a basic and/or photochemical catalytic reaction, with joint extraction, preferably continuously, of the symmetrical and/or asymmetrical disulphide(s) which it is desired to obtain. The process of the invention is particularly suited to the preparation of dimethyl disulphide or diethyl disulphide from a mixture of symmetrical and/or asymmetrical dialkyl disulphides.
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Paragraph 0071-0073
(2015/08/04)
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- Magnetic Fe3O4@MgAl-LDH composite grafted with cobalt phthalocyanine as an efficient heterogeneous catalyst for the oxidation of mercaptans
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Magnetically separable layered double hydroxide MgAl-LDH@Fe3O4 composite supported cobalt phthalocyanine catalyst was synthesized and used for the aerobic oxidation of mercaptans to corresponding disulfides under alkali free conditions. The catalyst exhibited excellent activity for the oxidation of mercaptans using molecular oxygen as an oxidant which can be effectively recovered by using an external magnetic field. In addition, the covalent immobilization of cobalt phthalocyanine to MgAl-LDH@Fe3O4 support prevents the leaching of the catalyst and improves its activity and stability.
- Kumar, Pawan,Gill, Kareena,Kumar, Sunil,Ganguly, Sudip K.,Jain, Suman L.
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- Haloacid/dimethyl sulfoxide-catalyzed synthesis of symmetrical disulfides by oxidation of thiols
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A novel method is developed for the oxidation of thiols to the corresponding disulfides using 20 mol % haloacid (HBr or HI) in combination with dimethyl sulfoxide. A tentative mechanism is proposed for the oxidation. In addition to the advantages of cost-effectiveness, simple processes, and broad functional group tolerance, the exclusive formation of disulfides is the principle reward of this methodology while compared to known methods that further oxidize disulfides to S-oxides and other byproducts.
- Natarajan, Palani,Sharma, Himani,Kaur, Mandeep,Sharma, Pooja
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supporting information
p. 5578 - 5582
(2015/09/21)
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- Graphene Oxide-Assisted One-Pot and Odorless Synthesis of Symmetrical Disulfides Using Primary and Secondary Alkyl Halides (Tosylates) and Thiourea as Sulfur Source Reagent
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Graphene oxide is described as a heterogeneous oxidant for the synthesis of symmetrical disulfides through the in situ generation of thiols from primary and secondary alkyl halides (tosylates) and thiourea in wet acetonitrile. A variety of alkyl halides and alkyl tosylates can be converted to corresponding disulfides in good to excellent yields. This strategy is free of foul-smelling thiols.
- Khalili, Dariush
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p. 1727 - 1734
(2015/12/12)
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- Ultrasound-Accelerated Synthesis of Asymmetrical Thiosulfonate S-Esters by Base-Promoted Reaction of Sulfonyl Chlorides with Thiols
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Amberlyst A-26, Mg-Al hydrotalcite, potassium fluoride absorbed on alumina, triethylamine and pyridine have been tested as base catalysts and reagents for the reaction of sulfonyl chlorides with thiols to prepare thiosulfonate S-esters. The reactions were performed under solvent-free conditions or with a minimum amount of solvent assisted by magnetic stirring, ultrasound irradiation and microwave irradiation. Ultrasound irradiation has good effects on the synthesis of sterically hindered thiosulfonate S-esters in solvent-free media as well as in a minimum amount of anhydrous diethyl ether.
- Pham, Hien Thi,Nguyen, Ngoc-Lan Thi,Duus, Fritz,Luu, Thi Xuan Thi
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p. 1934 - 1941
(2015/12/12)
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- One-pot efficient synthesis of disulfides from alkyl halides and alkyl tosylates using thiourea and elemental sulfur without contamination by higher polysulfides
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An efficient and odorless synthesis of disulfides from alkyl halides using thiourea and elemental sulfur in the presence of sodium carbonate in wet polyethylene glycol (PEG 200) at 40 C without contamination by higher polysulfides has been developed. This procedure was then extended to preparation of disulfides from alkyl tosylates at 70 C.
- Abbasi, Mohammad,Mohammadizadeh, Mohammad Reza,Taghavi, Zeinab Khatoon
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p. 201 - 205
(2013/07/26)
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- Formation, spectroscopic characterization, and solution stability of an [Fe4S4]2+ cluster derived from β-cyclodextrin dithiolate
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The formation and solution properties, including stability in mixed aqueous-Me2SO media, have been investigated for an [Fe 4S4]2+ cluster derived from β-cyclodextrin (CD) dithiolate. Clusters of the type [Fe4S4(SAr) 4]2- (Ar = Ph, C6H4-3-F) are generated in Me2SO by redox reactions of [Fe4S 4(SEt)4]2- with 2 equiv of ArSSAr. An analogous reaction with the intramolecular disulfide of 6A,6 D-(3-NHCOC6H4-1-SH)2-6 A,6D-dideoxy-β-cyclodextrin (14), whose synthesis is described, affords a completely substituted cluster formulated as [Fe 4S4{β-CD-(1,3-NHCOC6H4S) 2}2]2- (15). Ligand binding is indicated by a circular dichroism spectrum and also by UV-visible and isotropically shifted 1H NMR spectra and redox behavior convincingly similar to [Fe 4S4(SPh)4]2-. One formulation of 15 is a single cluster to which two dithiolates are bound, each in bidentate coordination. With there being no proven precedent for this binding mode, we show that the cluster [Fe4S4(S2-m-xyl) 2]2- is a single cubane whose m-xylyldithiolate ligands are bound in a bidentate arrangement. This same structure type was proposed for a cluster formulated as [Fe4S4{β-CD-(1,3-SC 6H4S)2}2]2- (16; Kuroda et al. J. Am. Chem. Soc.1988, 110, 4049-4050) and reported to be water-stable. Clusters 15 and 16 are derived from similar ligands differing only in the spacer group between the thiolate binding site and the CD platform. In our search for clusters stable in aqueous or organic-aqueous mixed solvents that are potential candidates for the reconstitution of scaffold proteins implicated in cluster biogenesis, 15 is the most stable cluster that we have thus far encountered under anaerobic conditions in the absence of added ligand.
- Lo, Wayne,Zhang, Ping,Ling, Chang-Chun,Huang, Shaw,Holm
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p. 9883 - 9892
(2012/11/13)
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- CARBOCATALYSTS FOR CHEMICAL TRANSFORMATIONS
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The disclosure relates to catalytically active carbocatalysts, e.g., a graphene oxide or graphite oxide catalyst suitable for use in a variety of chemical transformations. In one embodiment, it relates to a method of catalyzing a chemical reaction of an organic molecule by reacting the organic molecule in the presence of a sufficient amount of graphene oxide or graphite oxide for a time and at a temperature sufficient to allow catalysis of a chemical reaction. According to other embodiments, the reaction may be an oxidation reaction, a hydration reaction, a dehydrogenation reaction, a condensation reaction, or a polymerization reaction. Some reactions may include auto-tandem reactions. The disclosure further provides reaction mixtures containing an organic molecule and graphene oxide or graphite oxide in an amount sufficient to catalyze a reaction of the organic molecule.
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Page/Page column 56-57
(2011/12/14)
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- Distinct catalytic effect of micellar solution of sodium dodecyl sulfate (sds) for one-pot conversion of alkyl halides to disulfides via an odourless process using thiourea and mno2
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A novel one-pot odourless synthesis of symmetrical disulfides from their corresponding halides in aqueous mediausing thiourea and MnO2 in the presence of NaHCO3 or Na2CO3 catalyzed by micellar solution of sodium dodecyl sulfate (SDS) is described. By this method, primary, allylic and benzylic halides were converted into their corresponding disulfides in high yields.
- Firouzabadi, Habib,Iranpoor, Nasser,Abbasi, Mohammad
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experimental part
p. 698 - 702
(2010/08/08)
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- A one-pot, efficient, and odorless synthesis of symmetrical disulfides using organic halides and thiourea in the presence of manganese dioxide and wet polyethylene glycol (PEG-200)
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Primary, secondary, tertiary, allylic, and benzylic halides are converted efficiently into symmetric disulfides in high yields using thiourea as the sulfur atom source. The reactions are odorless and are performed at 30-35 °C in wet PEG-200 using MnO2 as an oxidant.
- Firouzabadi, Habib,Iranpoor, Nasser,Abbasi, Mohammad
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experimental part
p. 508 - 509
(2010/10/02)
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- Amine-catalyzed preparation of oxygenated derivatives of symmetric trisulfides
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Bipyridinium tribromide reacts with thiols in the presence of thionyl chloride to yield symmetric trisulfide derivatives (RSS(O)SR) as the major products. Two possible mechanisms are advanced to explain the chemistry.
- Pourshahbaz, Mahbubeh,Joshaghani, Mohammad,Rafiee, Ezzat,Shahmoradi, Jahangir,Emami, Fereshteh,Iranpour, Asieh
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scheme or table
p. 5987 - 5989
(2010/01/18)
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- Photosensitized electron transfer oxidation of sulfides: A steady-state study
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The photosensitized electron-transfer oxidation of a series of ethyl sulfides RSEt (1, R = C12H25; 2, PhCH2CH 2; 3, PhCH2; 4, PhCMe2; 5, Ph2CH) has been examined in acetonitrile and the product distribution discussed on the basis of the mechanisms proposed. In nitrogen-flushed solutions, cleaved alcohols and alkenes are formed, whereas under oxygen, in reactions that are 10-70 times faster, sulfoxides and cleaved aldehydes and ketones are formed in addition to the afore-mentioned products. Two sensitizers are compared, 9,10-dicyanoanthracene (DCA) and 2,4,6-triphenylpyrylium tetrafluoroborate (TPP+BF4-), the former giving a higher proportion of the sulfoxide, the latter of cleaved carbonyls. The sulfoxidation is due to the contribution of the singlet oxygen path with DCA. Oxidative cleavage, on the other hand, occurs both with DCA and with TPP+ which is known to produce neither singlet oxygen nor the superoxide anion. This process involves deprotonation from the α position of the sulfide radical cation, but the TPP+ results suggest that O2.- is not necessarily involved and non-activated oxygen forms a weak adduct with the radical cation promoting α-hydrogen transfer, particularly with benzylic derivatives. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Bonesi, Sergio M.,Fagnoni, Maurizio,Albini, Angelo
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scheme or table
p. 2612 - 2620
(2009/04/05)
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- Efficient oxidative coupling of thiols into disulfides using N-tert-butyl-N-chlorocyanamide
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Reaction of aliphatic/aromatic/heterocyclic thiols with N-tert-butyl-N-chlorocyanamide in presence of sodium bromide is described. The reaction was very rapid and resulted in the formation of disulfides in excellent yields under mild conditions.
- Kumar, Vinod,Kaushik, Mahabir Parshad
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experimental part
p. 160 - 162
(2009/04/06)
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- Selective thiylation of 1-vinylpyrrole-2-carbaldehydes: Synthesis of the novel pyrrole synthons 2-[bis(ethylsulfanyl)methyl]-1-vinylpyrroles and 1-(2-ethylthioethyl)pyrrole-2-carbaldehydes
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1-Vinylpyrrole-2-carbaldehydes have been selectively thiylated with ethanethiol either at the aldehyde (acid catalysis) or at the N-vinyl group (free-radical initiation) to afford 1-vinylpyrrole-2-carbaldehyde thioacetals (88-99% yield) or 1-(2-ethylthioethyl)pyrrole-2-carbaldehydes (68-89% yield), respectively. Both derivatives constitute important new families of pyrrole building blocks. Exhaustive thiylation at both the aldehyde and vinyl functionalities was achieved by acid-catalyzed reaction of the ethylthioethyl derivative of pyrrole-2-carbaldehyde with ethane thiol. An unexpected reduction of the ethylthioacetal group by ethanethiol to give the ethylthiomethyl group under free-radical initiation was also observed and is discussed. Georg Thieme Verlag Stuttgart.
- Vasil'tsov, Alexander M.,Ivanov, Andrey V.,Ushakov, Igor A.,Mikhaleva, Al'bina I.,Trofimov, Boris A.
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p. 452 - 456
(2007/12/27)
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- H14[NaP5W30O110] as a heterogeneous recyclable catalyst for the air oxidation of thiols under solvent free conditions
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The catalytic oxidation of thiols to the corresponding disulfides using Preyssler's catalyst H14[NaP5W30O 110] has been studied. These highly selective oxidations gave good yields of the target disulfides.
- Hekmatshoar, Rahim,Sajadi, Sodeh,Heravi, Majid M.,Bamoharram, Fatemeh F.
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p. 2223 - 2228
(2008/02/11)
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- Iron (III) perchlorate adsorbed on silica gel: A reagent for organic functional group transformations
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Adsorption of Fe(ClO4)3(H2O)6 onto chromatographic-grade silica gel in the presence of organic solvents (S=water, acetonitrile, or lower fatty acids) produces a supported reagent, Fe(ClO4)3(S)6/SiO2. This reagent has been found to be effective for the rapid organic functional group transformations such as dimerization of alkynes, aromatic hydrocarbons, selective oxidation of thiols to disulfides, and transannular reactions in 1,5-cyclooctadienes on grinding using pestle and mortar in the solid state. Copyright Taylor & Francis Group, LLC.
- Parmar, Anupama,Kumar, Harish
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p. 2301 - 2308
(2008/02/10)
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- Simple method for the preparation of symmetrical alkyl and aryl disulfides with alkyl sulfonyl halides in nitrogenous base
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In the present study, the reaction of thiols with alkyl sulfonyl halides was carried out in a nitrogenous base to compare the reactivity of -SH with that of -OH, which, however, led to the formation of disulfides. The reaction achieved as a result offers the use of an inexpensive reagent, quantitative yields of the product, and simplicity for the formation of the S-S bond. Copyright Taylor & Francis Group, LLC.
- Ali, Firdous Imran,Hashmi, Imran Ali,Siddiqui, Bina S.,Rasheed, Munawwer
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p. 2461 - 2465
(2008/02/10)
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- Oxidation of thiols to bisulfides using silica chloride as a heterogeneous catalyst
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Silica chloride is used as a selective and effective heterogeneous catalyst for the rapid conversion of thiols to disulfides with quantitative yields in a very short period of time. Copyright
- Sathe, Manisha,Ghorpade, Ramarao,Kaushik, Mahabir Parshad
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p. 1048 - 1049
(2007/10/03)
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- Oxidation of thiols to disulfides with monochloro poly(styrenehydantoin) beads
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Various thiols were converted to symmetrical disulfides. This facile and reproducible method uses water as a solvent, and monochloro poly(styrenehydantoin) beads as an oxidizing agent.
- Akdag, Akin,Webb, Thomas,Worley
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p. 3509 - 3510
(2007/10/03)
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- Simple, extremely fast, and high-yielding oxidation of thiols to disulfides
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Results of oxidation of thiols to disulfides with 1,3-dibromo-5,5-dimethyl- hydantoin (DBDMH) are described. A simple addition of 0.20-0.25 mol equivalent of solid DBDMH to thiol in chloroform at room temperature yielded the disulfides in excellent yield. The reaction is extremely fast and gave no other oxidized side products. Copyright Taylor & Francis, Inc.
- Alam, Ashraful,Takaguchi, Yutaka,Tsuboi, Sadao
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p. 1329 - 1333
(2007/10/03)
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- A new reagent for the efficient synthesis of disulfides from alkyl halides
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Benzyltriethylammonium tetracosathioheptamolybdate [(C6H5CH2N(Et)3)6Mo 7S24] has been found to be a superior sulfur transfer reagent for the conversion of alkyl halides to the corresponding disulfides in excellent yields under very mild reaction conditions.
- Polshettiwar, Vivek,Nivsarkar, Manisha,Acharya, Jyotiranjan,Kaushik
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p. 887 - 889
(2007/10/03)
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- Method for preparing aromatic diphenyl thioethers
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The invention concerns a method for preparing aromatic diphenyl thioethers. More particularly the invention concerns the preparation of 4-chloro-4′-thiomethyldiphenylether. The inventive method for preparing an aromatic diphenyl thioether is characterised in that it consists in reacting in an aqueous medium a diazonium salt of an aromatic diphenyl compound with a disulphide sulphur compound, in the presence of an efficient amount of a coupling catalyst.
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- Oxidative coupling of thiols to disulfides with Ti(IV) in the presence of NaI under air atmosphere
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Ti(IV) as TiCl3(O3SCF3) and TiO(O 2CCF3)2 are used as efficient catalysts for oxidative coupling of aliphatic, aromatic and heteroaromatic thiols to their disulfides in the presence of NaI under air atmosphere.
- Zeynizadeh, Behzad,Iranpoor, Nasser
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p. 849 - 852
(2007/10/03)
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- Oxidation of thiols to disulfides with molecular bromine on hydrated silica gel support
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Results of oxidation of thiols to disulfides with molecular bromine on silica gel solid support are reported. The procedure utilizes organic media and does not require a base to neutralize HBr by-products to suppress acid promoted side reactions. Utilization of silica gel support simplifies work up and product isolation.
- Ali, Mohammed Hashmat,McDermott, Mario
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p. 6271 - 6273
(2007/10/03)
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- New Routes to Poly(Alkylene Sulfidoselenides)
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A procedure was developed for preparing mixed poly(alkylene sulfidoselenides) by simultaneous dissolution of sulfur and selenium in basic reducing systems NaOH (KOH)-N2H4 * H2O-H2O, followed by alkylation of the resulting solutions with bielectrophilic agents.
- Deryagina, E. N.,Grabelnykh, V. A.,Russavskaya, N. V.,Alekminskaya, O. V.
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p. 1729 - 1733
(2007/10/03)
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- Liquid-phase oxidation of thiols with chlorine dioxide
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The products and kinetics of the liquid-phase oxidation of 11 aliphatic and aromatic thiols with chlorine dioxide were studied at -10-+70 °C in organic media. The rate constants and activation parameters of the reaction were determined. The influence of the thiol structure on its reactivity was studied. A strong solvent effect on the reaction rate constant was found, and the reaction mechanism was proposed.
- Yakupov,Shereshovets,Imashev,Ismagilov
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p. 2352 - 2355
(2007/10/03)
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