Reaction Of Disulfide Research Articles

Cyclic and linear amidine catalysts for the efficient synthesis of cyclic trithiocarbonates from carbon disulfide and episulfides under mild conditions

Cyclic and linear amidines effectively catalyzed the reaction of carbon disulfide and episulfides under mild conditions, such as ordinary pressure and ambient temperature, to give the corresponding cyclic trithiocarbonates in high yields.

Gas-Phase Reactions of Dimethyl Disulfide with Aliphatic Carbanions - A Mass Spectrometry and Computational Study

Ion-molecule reactions of Me2S2 with a wide range of aliphatic carbanions differing by structure and proton affinity values have been studied in the gas phase using mass spectrometry techniques and DFT calculations. The analysis of the spectra shows a variety of product ions formed via different reaction mechanisms, depending on the structure and proton affinity of the carbanion. Product ions of thiophilic reaction (m/z 47), SN2 (m/z 79), and E2 elimination – addition sequence of reactions (m/z 93) can be observed. Primary products of thiophilic reaction can undergo subsequent SN2 and proton transfer reactions. Gibbs free energy profiles calculated for experimentally observed reactions using PBE0/6-311+G(2d,p) method show good agreement with experimental results.Graphical ᅟ

Distance-regulating surface plasmon catalyzed coupling reaction of p-nitrophenyl disulfide.

In this study, we attempted to regulate the intermolecular distance of PNTP molecules on the surface of silver foil by breaking the S–S bond of NPDS. Though changing the laser wavelength and power, SERS conditions, the Raman spectra of NPDS and PNTP with different concentrations were compared. We found that, under SERS conditions, NPDS converted more efficiently than PNTP to DMAB at low-concentration with low-power and low-energy irradiation. The results indicate that the distance between molecules plays a significant role in the reaction of PNTP to form DMAB.

Determination of pH-independent rate constants of thiolate–disulfide redox transitions

Real-time evolution of qNMR spectra combined with detailed protonation constant data affords kinetic constants pertaining to thiolate–disulfide reactions with specific chemical species.

Palladium-Catalyzed Copper-Promoted Hiyama-Type Carbon–­Carbon Cross-Coupling Reactions of Dihetaryl Disulfides as ­Electrophiles

Dihetaryl disulfides were used as electrophiles in a palladium-catalyzed carbon–carbon cross-coupling reaction with arylsilanes to ­realize a Hiyama-type reaction. This unique transformation shows high reactivity, excellent functional-group tolerance, and mild reaction conditions, making it an attractive alternative to conventional cross-coupling approaches for carbon−carbon bond construction.

Effects of electric fields on copper sulfide deposition and the properties of insulating oils in oil-immersed transformers

The failures of high-voltage transformers and reactors can result from the deposition of copper sulfide on the oil-impregnated paper insulation. This study explored the influence of electric fields on copper sulfide deposition and the properties of insulating oils as a result of the reaction of dibenzyl disulfide (DBDS) with copper in oil-immersed transformers. Accelerated aging experiments were conducted for pig-tail windings under two sets of conditions, namely, thermal aging only at 140 °C and AC/DC electrical and thermal aging at 5 kV/140 °C under low oxygen condition. This was combined with oil containing dibenzyl disulfide (DBDS) added to the non-corrosive oil to a concentration of 200 mg/kg. The corrosive sulfur deposits were examined by observing the surface morphology of the windings and measuring the copper and sulfur contents on the windings via inductively coupled plasma-atomic emission spectrometry and a precipitation method. The properties of the insulating oils were measured and analyzed at intervals. The results indicate that electric fields increased the amount of deposited copper sulfide on the windings. The higher the electric field strength, the higher the amount of deposited copper sulfide on the insulating paper surface. Subjecting the oil-paper insulation to electric field and elevated temperature generates dissolved copper in the insulating oil. The electric field can promote the dissolution of copper in oil. The ageing oil under thermal and electrical stresses promote copper dissolution and increase corrosion rate.

The palladium‐catalyzed C‐N cross‐coupling reaction of diheteroaryl disulfides with heterocyclic amines

The Pd‐catalyzed cross‐coupling reaction of 1, 2‐di(pyrimidin‐2‐yl) disulfides with heterocyclic amines including 2‐amino pyrimidines and 1,3,4‐thiadiazol‐2‐amines to deliver symmetrical C‐N coupling products in moderate to good yields is reported. This method provides an opportunity for synthesis of bioactive molecules and pharmaceutically interesting compounds containing heterocycle motifs. The reported protocol shows good functional group compatibility, and provides a new strategy for preparation of C2‐amination pyrimidine derivatives from heterocyclic disulfides.

Synthesis of vinyl thioethers and bis-thioethenes from calcium carbide and disulfides

Bis-thioethenes and vinyl thioethers were obtained from the reaction of disulfides and calcium carbide in good to high yields using a simple synthetic procedure and common laboratory setup. The tolerance of the reaction was investigated by the examples of aliphatic, aromatic, heteroaromatic and sesquiterpenic substrates.

Selectively synthesis of cyclic di- and trithiocarbonates by N-heterocyclic carbene/LiCl(Br) catalyzed addition of carbon disulfide to epoxides

Carbon disulfide is an abundant, inexpensive and readily available material. One of the main challenges in the reaction of epoxides with CS2 is to control the chemoselectivity as a variety of compounds would be formed in the reaction. A simple and convenient method toward selectively synthesis of oxathiolane and trithiocarbonate from epoxides with CS2 catalyzed by NHC/LiCl(Br) under the neat conditions has been developed. This catalytic system exhibits excellent activity and selectivity in cycloaddition reactions of carbon disulfide to terminal epoxides.

The Reaction of Diethylthiophosphinyl Iodide, Et2P(S)I, with Nucleophiles

The compound Me2AsSI can exist in two different forms, either as dimethylarsinosulfenyl iodide [or (iodothio)dimethylarsane)], Me2As–S–I (A), or as dimethylthioarsinyl iodide (or dimethylarsinothioic iodide), Me2As(S)–I (B). To confirm that the structure of the product of the reaction between Bunsen's cacodyl disulfide Me2As(S)–S–AsMe2 and iodine is A and not B, the known diethylthiophosphinyl iodide (or diethylphosphinothioic iodide), Et2P(S)–I (2) was prepared and its hydrolytic stability and reactivity towards a variety of nitrogen, phosphorus(III), arsenic(III), oxygen, and sulfur(II) nucleophiles were studied. The results indicated that only a few reactions of 2 resembled those of A, thus strengthening the proposal that the reaction of Bunsen's cacodyl disulfide with iodine produced A and not B. A series of 31P NMR chemical shifts of diethylthiophosphinyl moiety is also reported. Et2P(S)–DMAP, synthesized and isolated during the presented study, is the ethyl analogue of Me2P(S)–DMAP, previously described as an important molecule. In our case, Et2P(S)–DMAP was found to be a good intermediate for the synthesis of phosphoryl or thiophosphoryl derivatives since it was more reactive than 2 towards nucleophiles.

NHC-Catalyzed Metathesis and Phosphorylation Reactions of Disulfides: Development and Mechanistic Insights.

The development of efficient methods for the metathesis and phosphorylation reactions of disulfide compounds is of widespread interest due to their important synthetic utility in polymer, biological, medicinal and agricultural chemistry. Herein, we demonstrate the use of N-heterocyclic carbenes (NHCs) as versatile organocatalysts to promote these challenging reactions under mild conditions. This metal- and oxidant-free protocol is operationally simple with very short reaction times. The interplay between the nucleophilicity and basicity of NHCs in these reactions were also elucidated by NMR studies and high-level ab initio calculations.

Disulfide-induced self-assembled targets: A novel strategy for the label free colorimetric detection of DNAs/RNAs via unmodified gold nanoparticles

A modified non-cross-linking gold-nanoparticles (Au-NPs) aggregation strategy has been developed for the label free colorimetric detection of DNAs/RNAs based on self-assembling target species in the presence of thiolated probes. Two complementary thiol- modified probes, each of which specifically binds at one half of the target introduced SH groups at both ends of dsDNA. Continuous disulfide bond formation at 3′ and 5′ terminals of targets leads to the self-assembly of dsDNAs into the sulfur- rich and flexible products with different lengths. These products have a high affinity for the surface of Au-NPs and efficiently protect the surface from salt induced aggregation. To evaluate the assay efficacy, a small part of the citrus tristeza virus (CTV) genome was targeted, leading to a detection limit of about 5 × 10−9 mol.L−1 over a linear ranged from 20 × 10−9 to 10 × 10−7 mol.L−1. This approach also exhibits good reproducibility and recovery levels in the presence of plant total RNA or human plasma total circulating RNA extracts. Self-assembled targets can be then sensitively distinguished from non-assembled or mismatched targets after gel electrophoresis. The disulfide reaction method and integrating self-assembled DNAs/RNAs targets with bare AuNPs as a sensitive indicator provide us a powerful and simple visual detection tool for a wide range of applications.

One‐pot Three Component Synthesis of ω‐(oxathiolan‐2‐thion‐5‐yl)‐α‐oxazolidin‐2‐ones

We report a practical and one‐pot synthesis of novel series of ω‐(oxathiolan‐2‐thione‐5‐yl)‐α‐ oxazolidin‐2‐ones (3a‐h). The obtained compounds have been designed, synthesized via reaction of oligoethylene glycols diglycidyl ethers, isocyanate and carbon disulfide in the presence of catalytic amount of lithium bromide. A variety of important oxazolidinone derivatives can be obtained from simple starting materials in good yields and the biological activity of these new products will be investigated in complementary study.

Fatty Acid Methyl Esters with Two Vicinal Alkylthio Side Chains and Their NMR Characterization

AbstractThe addition reaction of dimethyl disulfide (DMDS) to double bonds in alkenes and monounsaturated fatty acid esters in the presence of iodine or other catalysts to give bis(methylthio) derivatives has largely served analytical purposes in mass spectrometry with scattered reports on the addition of other disulfides to alkenes also existing. In this work, this iodine‐catalyzed reaction was expanded to include the addition of other dialkyl disulfides (RSSR; R=ethyl, propyl, butyl, iso‐propyl) besides DMDS to the double bonds in monounsaturated fatty acid methyl esters with 16, 18, 20, and 22 carbon atoms in the fatty acid chain to give the corresponding methyl 1,2‐bis(alkylthio)alkanoates. The products are obtained in high to moderate yield after a facile purification procedure and are analytically characterized not only by mass spectrometry but also 1H and 13C NMR. The threo and erythro diastereomers obtained from (Z) and (E) fatty acid methyl esters, respectively, can be easily distinguished by the NMR shifts of the protons and carbons in and close to the 1,2‐bis(alkylthio) moiety. Various other effects in the NMR spectra are discussed. The 1,2‐bis(alkylthio) derivatives of a symmetrical alkene, 7(E)‐tetradecene, serve to confirm the NMR assignments besides NMR techniques such as 2D correlations and DEPT. The compounds may show properties of interest for various applications.

Self‐Neutralizing Carbonic Acidic Catalyzed Synthesis of Benzothiazole Derivatives from Disulfides and Aldehydes in Water

AbstractAn environmental friendly method was developed for preparing benzothiazole derivatives via the reaction of ortho‐anilino disulfides with aldehydes promoted by Na2S⋅9H2O in a reversible CO2‐H2O system without any other acid additive or organic solvent. Thus, this reaction system greatly simplifies post‐processing and allows for disposal without waste. The highly selective protocol affords the corresponding benzothiazoles from the reaction of disulfides and aldehydes with electron‐donating or withdrawing groups in good yields. Moreover, the dynamic equilibrium relationship between Na2S and the CO2 pressure had been explored by 13CNMR in high‐pressure NMR tube, which firstly demonstrated the carbonic acid was converted into CO32− or HCO3− promoted by Na2S in low or high CO2 pressure. Furthermore, the mechanism of Schiff base formation catalyzed by acid was confirmed by 1HNMR, and the process of benzothiazole formation from disulfide mediated by Na2S in CO2‐H2O system was also proposed.

The effects of exfoliation, organic solvents and anodic activation on the catalytic hydrogen evolution reaction of tungsten disulfide.

The rational design of transition metal dichalcogenide electrocatalysts for efficiently catalyzing the hydrogen evolution reaction (HER) is believed to lead to the generation of a renewable energy carrier. To this end, our work has made three main contributions. At first, we have demonstrated that exfoliation via ionic liquid assisted grinding combined with gradient centrifugation is an efficient method to exfoliate bulk WS2 to nanosheets with a thickness of a few atomic layers and lateral size dimensions in the range of 100 nm to 2 nm. These WS2 nanosheets decorated with scattered nanodots exhibited highly enhanced catalytic performance for HER with an onset potential of -130 mV vs. RHE, an overpotential of 337 mV at 10 mA cm-2 and a Tafel slope of 80 mV dec-1 in 0.5 M H2SO4. Secondly, we found a strong aging effect on the electrocatalytic performance of WS2 stored in high boiling point organic solvents such as dimethylformamide (DMF). Importantly, the HER ability could be recovered by removing the organic (DMF) residues, which obstructed the electron transport, with acetone. Thirdly, we established that the HER performance of WS2 nanosheets/nanodots could be significantly enhanced by activating the electrode surface at a positive voltage for a very short time (60 s), decreasing the kinetic overpotential by more than 80 mV at 10 mA cm-2. The performance enhancement was found to arise primarily from the ability of a formed proton-intercalated amorphous tungsten trioxide (a-WO3) to provide additional active sites and favourably modify the immediate chemical environment of the WS2 catalyst, rendering it more favorable for local proton delivery and/or transport to the active edge site of WS2. Our results provide new insights into the effects of organic solvents and electrochemical activation on the catalytic performance of two-dimensional WS2 for HER.

Ultrasound-Mediated Three-Component Reaction “On-Water” Protocol For the Synthesis of Novel Mono- and bis-1,3-Thiazin-4-one Derivatives

Green synthetic and catalyst-free strategy towards the synthesis of novel mono- and bis-1,3-thiazin-4-one scaffolds through a one pot, reaction of carbon disulfide, monoacetylenic esters and amines ...

Highly Reversible Diphenyl Trisulfide Catholyte for Rechargeable Lithium Batteries

Organotrisulfide (RSSSR) is a new class of high-capacity cathode materials for rechargeable lithium batteries. The organic R group can tune the structure and property of organotrisulfide as well as electrochemical performance in batteries. Herein, a nominal diphenyl trisulfide (DPTS, C6H5SSSC6H5) catholyte is reported for rechargeable lithium batteries. Three sulfur atoms allow 4e– storage per molecule, affording DPTS with a theoretical capacity of 428 mAh g–1. The DPTS catholyte is synthesized from a coupling reaction of diphenyl disulfide (DPDS) and elemental sulfur in liquid electrolyte at 70 °C. It is found that the DPTS catholyte is a mixture of DPTS, DPDS, and elemental sulfur in the electrolyte. The lithium cell with the DPTS catholyte delivers an initial specific capacity of 330 mAh g–1DPTS and retains 79% of the initial capacity over 100 cycles at the C/2 rate. The cell delivers an initial discharge specific energy of 751 Wh kg–1DPTS with a high energy efficiency of over 95% at the C/5 rate. The ...

Silver(I) complexes of methyl xanthate against human adenocarcinoma breast cancer cells

The sodium salt of methyl xanthate derives from the reaction of carbon disulfide and sodium hydroxide (1:1) in methanol. Addition of an acetonitrile solution of silver nitrate and tri-aryl-phosphine in 1:2 molar ratio, form the complexes with general formula [Ag(CH3OCS2)(Ar3P)2] (Ar3P=triphenylphosphine (tpp, 1), tri(p-tolyl)phosphine (tptp, 2) and tri(m-tolyl)phosphine (tmtp, 3)). The complexes have been characterized by melting point, FT-IR, UV–Vis, 1H, 31P NMR spectroscopic data and X-ray crystallography. The stability of the Ag–P bond in solution was determined by 31P NMR resonances signals. The photosensitivity of 1–3 against UVB radiation is studied by means of UV–Vis spectroscopy. The stronger photosensitivity is exhibited by 1. The LogP was calculated in order to correlate the influence of lipophilicity on biological activity. The steric demands of arylphosphine were assessed through determination of the cone angles, volumes and H-all atom contacts. Complex of tri(m-tolyl)phosphine exert the greatest steric repulsion (higher cone angle). Hirshfeld surface volumes (2 occupied the greatest space) were analyzed to clarify the nature of the intermolecular interactions. Complexes 1–3 were tested for their in vitro cytotoxic activity against human adenocarcinoma cancer cell lines: MCF-7 (breast, estrogen receptor (ER) positive), MDA-MB-231 (breast, estrogen receptor (ER) negative) and MRC-5 (normal human fetal lung fibroblast cells) with sulforhodamine B (SRB) colorimetric assay. Molecule 3 with the lower H-all atoms inter-molecular interactions exhibits the higher activity against MCF-7 cells. The results are correlated with those obtained from heteroleptic silver complexes of tri-aryl-phosphines and carboxylates analogs to 1–3 where the xanthate is replaced by carboxylates. The structure activity relationships (SAR) study underlines the significance of the ligand type on the bioactivity of these compounds.

Novel Synthesis of Tryptamine Derived 4‐Hydroxy‐4‐arylthiazolidine‐2‐thiones and 4‐Arylthiazole‐2(3H)‐thiones by Multicomponent Reactions

An efficient one‐pot multicomponent synthesis of 3‐(2‐(1H‐indol‐3‐yl)ethyl)‐4‐hydroxy‐4‐arylthiazolidine‐2‐thione and 3‐(2‐(1H‐indol‐3‐yl)ethyl)‐4‐arylthiazole‐2(3H)‐thione has been developed from a multicomponent reaction of tryptamine, carbon disulfide and phenacyl bromide. This protocol has an advantage such as operational simplicity, short reaction time, and affording good to excellent yields.