Sulfide Derivatives Research Articles

Magnetic nanoparticles supported Cu2+ and Ce3+ complexes: toward the chemical and electrochemical oxidation of alcohol and sulfide derivatives

Heterogeneous catalysts are more prominent rather than homogenous catalysts since they are simply separated from products. To improve and develop heterogeneous catalysts, two core–shell magnetic nanocatalysts are prepared by anchoring of Cu and Ce complexes on the surface of Fe3O4, then the efficiency of the obtained catalysts are tested toward both chemical and electrochemical oxidation of sulfide and alcohol derivatives. Characterization of mentioned catalysts was performed by using FT-IR, XRD, EDX and SEM. The obtained results confirm that the reported method has outstanding advantages such as short reaction time, high yield, easy operation, easy separation, inexpensive and non-toxic material and chemical and thermal stability.

Naphthalimide Aryl Sulfide Derivative Norrish Type I Photoinitiators with Excellent Stability to Sunlight under Near-UV LED

A series of Norrish type I photoinitiators (NASs), which are naphthalimide aryl sulfide derivatives, are prepared. The potential mechanism involved in the photolysis of NASs under UV LED at 405 nm ...

Editors' Choice—Highly Diastereoselective Anodic Fluorination of Organosulfur Compounds Based on Neighboring Participation

Highly diastereoselective and efficient anodic α-fluorination of phenyl, p-chlorophenyl, and 2-naphthyl 3,3,3-trifluoro-2-methoxypropyl sulfides was successfully carried out at platinum electrodes in Et3N-nHF (n = 3–5)/MeCN to provide the corresponding α-fluorinated products in good yields, whereas the corresponding p-methoxyphenyl sulfide derivative gave much lower diastereoselectivity. On the basis of such marked substituent effects on the diastereoselectivity and a previous study of anodic methoxylation of related sulfides, as well as the X-ray analysis of the configuration of the major diastereomer of the electrochemically fluorinated β-naphthyl derivative, it was clarified that the high diastereoselectivity is attributable to the neighboring MeO group participation to the anodically generated cationic intermediate destabilized by an electron-withdrawing CF3 group.

Square Planar Coordination of Silver in a η4‐Cyclobutadiene‐(η5‐C5H5)ReBr2 Complex Framework

Halide addition and abstraction experiments with the cationic rhenacyclopentatriene [(η5‐C5H5){ReC4(SBn)4}Br]BF4 and the side‐on cyclobutadiene complexes [(η5‐C5H5)(η4‐C4Ph4)ReX2] (X = Br, I), respectively, are described. Reversible interconversion of both coordination modes of the metal bonded C4R4 moiety depending on the presence or absence of the second bromide ligand is demonstrated for the sulfide derivative. However, formation of the [(η5‐C5H5)(ReC4Ph4)X]+ congener by halide abstraction at [(η5‐C5H5)(η4‐C4Ph4)ReX2] turned out to be impossible. Instead, formation of silver halide complexes with the halide bridging rhenium and silver under retention of the metalorganic scaffold are observed. Governed by the phenyl substituent framework a square‐planar coordination environment about the Ag cation is adopted for X = Br. Changing X = Br by X = I led to the formation of a heptanuclear complex with di‐ and three‐coordinate silver ions.

Yttrium-Catalyzed Regioselective α-C–H Silylation of Methyl Sulfides with Hydrosilanes

The catalytic C–H silylation of sulfides with hydrosilanes is of much interest and importance but has remained unexplored to date. We report here the C–H silylation of methyl sulfides with hydrosilanes by an yttrium metallocene catalyst. The reaction took place regioselectively at the α-methyl C–H bond, affording the corresponding silylated sulfide derivatives that are difficult to make by other means.

Fluorine-18 labeled diphenyl sulfide derivatives for imaging serotonin transporter (SERT) in the brain

ObjectivesSerotonin transporters (SERT) play an important role in controlling serotonin concentration in the synaptic cleft and in managing postsynaptic signal transduction. Inhibitors of SERT binding are well known as selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine, sertraline, paroxetine, and escitalopram, that are commonly prescribed antidepressants. Positron emission tomography (PET) and single photon emission tomography (SPECT) imaging agents targeting SERT may be useful for studying its function and providing a tool for monitoring drug treatment. MethodsA series of novel 18F-labeled diphenyl sulfide derivatives were prepared and tested for their binding affinity. Among them, 2-((2-((dimethylamino)-methyl)-4-(2-(2-fluoroethoxy)ethoxy)phenyl)thio)aniline, 1, which showed excellent binding toward serotonin transporter (SERT) in the brain (Ki = 0.09 nM), was selected for further evaluation. An active OTs intermediate, 7, was treated with [18F]F−/K222 to provide [18F]1 in one step and in high radiochemical yields. This new SERT targeting agent was evaluated in rats by biodistribution studies and animal PET imaging studies. ResultsThe radiolabeling reaction led to the desired [18F]1. After HPLC purification no-carrier-added [18F]1 was obtained (radiochemical yield, 23–47% (n = 10,); radiochemical purity >99%; molar activity, 15–28 GBq/μmol). Biodistribution studies with [18F]1 showed good brain uptake (1.04% dose/g at 2 min post-injection), high uptake into the hypothalamus (1.55% dose/g at 30 min), and a high target-to-non-target (hypothalamus to cerebellum) ratio of 6.1 at 120 min post-injection. A PET imaging study in normal rats showed excellent uptake in the midbrain and thalamus regions known to be rich in SERT binding sites at 60 min after iv injection. Chasing experiment with escitalopram (iv, 2 mg/kg) in a rat at 60 min after iv injection caused a noticeable reduction in the regional radioactivity and the target-to-non-target ratio, suggesting binding by [18F]1 was highly specific and reversible for SERT binding sites in the brain. ConclusionsA novel diphenyl sulfide derivative, [18F]1 for SERT imaging was successfully prepared and evaluated. Results suggest that this new chemical entity is targeting SERT binding sites in the brain, and it is a suitable candidate for future commercial development.

Zirconium oxide complex anchored on boehmite nanoparticles as highly reusable organometallic catalyst for C–S and C–O coupling reactions

Boehmite nanoparticles were prepared by a simple and inexpensive procedure in water using commercially available materials without inert atmosphere. Then, the surface of the boehmite nanoparticles was modified using 3‐mercaptopropyltrimethoxysilane and subsequently zirconium oxide was supported on the modified surface. Zirconium oxide supported on boehmite nanoparticles (Pr.S‐ZrO@boehmite) was characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and inductively coupled plasma technique. The catalytic application of Pr.S‐ZrO@boehmite was studied in C–O and C–S coupling reactions for synthesis of valuable compounds such as ether and sulfide derivatives. All products were obtained in good to excellent yields and the catalyst could be recovered and reused several times without significant loss of catalytic efficiency. Furthermore, zirconium oxide is rarely used as catalyst for cross‐coupling reactions.

Pd‐Catalyzed P–C Cross‐Coupling of Aryl Bromides and Triflates with Hydroxymethylphosphine Sulfide Derivatives

The development of a versatile process for phosphine synthesis has attracted considerable interest because organophosphines are indispensable for organic synthesis. Previously, we developed a Pd‐catalyzed P–C coupling reaction for hydroxymethylphosphine sulfide derivatives with various aryl iodides as a method for preparing a variety of triarylphosphine derivatives. However, the catalyst system for aryl iodides did not activate aryl bromides and triflates, which are more readily available than aryl iodides. Herein, we report a new and effective catalyst system for the P–C coupling of various aryl bromides and triflates with hydroxymethylphosphine sulfides. An application of the new method was demonstrated with the sequential synthesis of an unsymmetrically substituted triarylphosphine sulfide by using multiple couplings of an orthogonally protected precursor.

Aminkomplexe des Goldes, Teil 10: Gold(I)-thiocyanat-Komplexe mit Tetrahydrothiophen, Dimethylsulfid, Ammoniak, Aminen und Azaaromatena

Abstract The reaction of (tht)AuCl (tht=tetrahydrothiophene) with KSCN leads to a mixture of gold(I) thiocyanate AuSCN and [(tht)2Au]+ [Au(SCN)2]− 1. The compounds were separated and the X-ray structure of 1 confirmed as an alternating chain of anions and cations linked by aurophilic contacts. Either pure AuSCN or the mixture was used to synthesize further derivatives of AuSCN, all of which were investigated by X-ray methods. Most products were of limited stability when removed from their mother liquor. The dimethyl sulfide derivative 2 is molecular, (Me2S)AuSCN; the ammonia derivative 3 is ionic, [(NH3)2Au]+ [Au(SCN)2]−. The reaction with 2,2-bipyridyl leads (presumably by involvement of the solvent or of atmospheric moisture) to [bipy-H]+ [Au(SCN)2]− 13. All other products involve amines or azaaromatics as ligands L. The primary amine tert-butylamine forms an ionic product [L2Au]+ (SCN)− 4. The secondary amines piperidine and dibenzylamine lead to molecular structures LAuSCN (5 and 6), whereas pyridine-based azaaromatics lead to ionic products [L2Au]+ [Au(SCN)2]− with L=2-, 3- or 4-picoline (7–9), 2,4-, 3,4- or 3,5-lutidine (10–12). The 3,4-lutidine derivative 11 forms two polymorphs that tend to form mixed crystals. The dominant features of the crystal packing for 7–12 are short aurophilic interactions.

Synthesis and Antimicrobial Activity of Sulfur Derivatives of Quinolinium Salts.

A novel method for cleavage of the dithiine ring in 5,12-(dimethyl)-thioqinantrenium bis-chloride 1 “via” reaction with sodium hydrosulfide leads to 1-methyl-3-mercaptoquinoline-4(1H)-thione 2. Further transformation of thiol and thione functions of compound 2 leads to a series of sulfide and disulfide derivatives of quinolinium salts 4 and 6. 1-Methyl-4-chloro-3-benzylthioquinoline chloride 8 was obtained by N-alkylating 4-chloro-3-benzylthioquinoline using dimethyl sulfate. Antimicrobial activity of the obtained compounds was investigated using six Gram-positive and six Gram-negative bacterial strains, as well as Candida albicans yeast. Greater activity was demonstrated towards Gram-positive strains. MIC values for compounds and with benzylthio 4d and benzoylthio 4f substituents in 3-quinoline position were found to be in the 0.5–1 μg/mL range, at a level similar to that of ciprofloxacin (reference). Compounds 4d and 4f also demonstrated interesting antifungal properties (MIC = 1).

α-C-H Alkylation of Methyl Sulfides with Alkenes by a Scandium Catalyst.

The C-H addition of sulfides to alkenes is an atom-efficient route for the functionalization and modification of sulfide compounds through C-C bond formation, but this transformation is highly challenging. We report here the regioselective α-C(sp3)-H addition of a wide range of methyl sulfides to a variety of olefins and dienes by a half-sandwich scandium catalyst. This protocol provides a unique route for the synthesis of diverse sulfide derivatives through C-C bond formation at a sulfur-adjacent carbon atom in a 100% atom efficient fashion.

Synthesis and characterization of a new photochromic alkylene sulfide derivative

ABSTRACTA process has been developed for the synthesis of a new photochromic alkylene sulfide derivative. The process involves the synthesis of an alkylene sulfide with terminal free amino groups and a novel unsymmetrical photochromic diarylperfluorocyclopentene containing an aldehyde group, which coupled together to produce the corresponding Schiff base. The structures of the products were confirmed by a range of spectroscopic techniques.

Synthesis of the p-tert-butyl calix[4] arene symmetrical sulfide derivatives and its extraction properties towards U(VI) from aqueous solution

The p-tert-butyl calix[4]arene symmetrical sulfide derivatives (3a and 3b) were successfully synthesized using p-tert-butyl calix[4]arene as the raw material and were characterized by FT-IR. The effects of pH value, temperature, and contact time on the U(VI) extraction with compounds 3a and 3b from aqueous solution were systematically investigated. The results showed that the optimum pH value for uranium extraction was 4.0 and the extraction equilibration time was 90 min. It is also found that the pseudo-second-order kinetic model (R 2 > 0.999) was better fitted to the extraction process. The thermodynamic parameters of the enthalpy (ΔH θ) were all negative, indicating that the extraction reaction were exothermic reaction.

Polysulfides and products of H2S/S-nitrosoglutathione in comparison to H2S, glutathione and antioxidant Trolox are potent scavengers of superoxide anion radical and produce hydroxyl radical by decomposition of H2O2

Exogenous and endogenously produced sulfide derivatives, such as H2S/HS−/S2−, polysulfides and products of the H2S/S-nitrosoglutathione interaction (S/GSNO), affect numerous biological processes in which superoxide anion (O2−) and hydroxyl (OH) radicals play an important role. Their cytoprotective-antioxidant and contrasting pro-oxidant-toxic effects have been reported. Therefore, the aim of our work was to contribute to resolving this apparent inconsistency by studying sulfide derivatives/free radical interactions and their consequent biological effects compared to the antioxidants glutathione (GSH) and Trolox. Using the electron paramagnetic resonance (EPR) spin trapping technique and O2−, we found that a polysulfide (Na2S4) and S/GSNO were potent scavengers of O2− and cPTIO radicals compared to H2S (Na2S), GSH and Trolox, and S/GSNO scavenged the DEPMPO-OH radical. As detected by the EPR spectra of DEPMPO-OH, the formation of OH in physiological solution by S/GSNO was suggested. All the studied sulfide derivatives, but not Trolox or GSH, had a bell-shaped potency to decompose H2O2 and produced OH in the following order: S/GSNO > Na2S4 ≥ Na2S > GSH = Trolox = 0, but they scavenged OH at higher concentrations. In studies of the biological consequences of these sulfide derivatives/H2O2 properties, we found the following: (i) S/GSNO alone and all sulfide derivatives in the presence of H2O2 cleaved plasmid DNA; (ii) S/GSNO interfered with viral replication and consequently decreased the infectivity of viruses; (iii) the sulfide derivatives induced apoptosis in A2780 cells but inhibited apoptosis induced by H2O2; and (iv) Na2S4 modulated intracellular calcium in A87MG cells, which depended on the order of Na2S4/H2O2 application. We suggest that the apparent inconsistency of the cytoprotective-antioxidant and contrasting pro-oxidant-toxic biological effects of sulfide derivatives results from their time- and concentration-dependent radical production/scavenging properties and their interactions with O2−, OH and H2O2. The results imply a direct involvement of sulfide derivatives in O2− and H2O2/OH free radical pathways modulating antioxidant/toxic biological processes.

New carborane-containing acids and amines

Alkylation of nido-carborane methyl sulfide derivative [9-MeS-7,8-C2B9H11]– was used to synthesize a series of new carborane-containing acids 9-HOOC(CH2) n (Me)S-7,8-C2B9H11 (n = 1—4) and amines 9-H2N(CH2) n (Me)S-7,8-C2B9H11 (n = 2, 3). The compounds obtained can be used for the development of BNCT agents.

Synthesis and characterization of sulfide, sulfoxide and sulfone derivatives of thiopyran: antimicrobial evaluation

A series of thiopyran derivatives and their oxidized analogous forms were synthesized and characterized by FT-IR, 1H, 13C, 31P NMR and mass spectroscopy techniques. The antibacterial and antifungal activities of these synthesized materials were evaluated against Staphylococcus aureus and Bacillus subtilis, as Gram-positive bacteria, and Escherichia coli and Pseudomonas aeruginosa, as Gram-negative bacteria, as well as the fungus Candida albicans. The results revealed that thiopyran S,S-dioxides are the most effective against all the bacteria studied in this work. Furthermore, thiopyran S-oxides showed excellent antifungal activity against Candida albicans.

Bis(6-methylene-2,2'-bipyridine)phenylphosphine-A Flexible Ligand for the Construction of Trinuclear Coinage-Metal Complexes.

Bis-(6-methylene-2,2'-bipyridine)phenylphosphine (PN4) was designed as a tailor-made ligand with different metal binding sites (N and P) to support metallophilic interactions between the different coinage metals, as these are far less common than homometallic interactions, typically between gold(I) ions. Furthermore, the phosphorus(V)sulfide derivative of PN4 was synthesized to get additional structural information in the solid state. Two mononuclear gold complexes [(PN4)AuCl] and [(PN4)2 Au]ClO4 were synthesized first. Then, the two hetero trimetallic gold complexes [(PN4)2 AuAg2 ](OTf)3 (Tf=triflate) and [(PN4)2 AuCu2 ](OTf)3 were synthesized by selectively filling the bipyridine coordination compartments with the lighter coinage metals. For comparison two trinuclear silver complexes, that is, [(PN4)2 Ag3 ]OTf and [(PN4)(py)2 Ag3 (μ-Cl)(μ3 -Cl)]ClO4 (py=pyridine) were prepared. All compounds were fully characterized including single-crystal X-ray diffraction, 15 N,19 F and 109 Ag NMR spectroscopy. The photophysical properties of the new compounds were determined in the solid state. These revealed a different behavior between the Au-Cu and Au-Ag/Ag-Ag compounds. [(PN4)2 AuAg2 ](OTf)3 was found to be the brightest emitter. Time-dependent density functional calculations were performed to illuminate the differences in the photophysical properties.

Synthesis and Bioactivity of Novel Bis-heterocyclic Amide Modified Sulfide Derivatives

Synthesis and Bioactivity of Novel Bis-heterocyclic Amide Modified Sulfide Derivatives

Inhibition of Leishmania infantum trypanothione reductase by diaryl sulfide derivatives

The study presented here aimed at identifying a new class of compounds acting against Leishmania parasites, the causative agent of Leishmaniasis. For this purpose, the thioether derivatives of our in-house library have been evaluated in whole-cell screening assays in order to determine their in vitro activity against Leishmania protozoan. Among them, promising results have been achieved with compound RDS 777 (6-(sec-butoxy)-2-((3-chlorophenyl)thio)pyrimidin-4-amine) (IC50 = 29.43 µM), which is able to impair the mechanism of the parasite defence against the reactive oxygen species by inhibiting the trypanothione reductase (TR) with high efficiency (Ki 0.25 ± 0.18 µM). The X-ray structure of L. infantum TR in complex with RDS 777 disclosed the mechanism of action of this compound that binds to the catalytic site and engages in hydrogen bonds the residues more involved in the catalysis, namely Glu466', Cys57 and Cys52, thereby inhibiting the trypanothione binding and avoiding its reduction.

ChemInform Abstract: Wittig—Horner Mediated Synthesis of 4‐Vinyl Sulfide Derivatives of Pyrazoles.

AbstractBuLi‐mediated Wittig—Horner reactions of 4‐formylpyrazoles with arylthiophosphonates result in a synthesis of E/Z‐mixtures of 4‐vinyl sulfide derivatives.