Vinyl Sulfides Research Articles

Rhodium-Catalyzed Tetrasubstituted Vinyl Sulfides (TVSs) Synthesis

Rhodium-Catalyzed Tetrasubstituted Vinyl Sulfides (TVSs) Synthesis

Modular and stereoselective synthesis of tetrasubstituted vinyl sulfides leading to a library of AIEgens

Tetraarylethylenes exhibit intriguing photophysical properties and sulfur atom frequently play a vital role in organic photoelectric materials and biologically active compounds. Tetrasubstituted vinyl sulfides, which include both sulfur atom and tetrasubstituted alkenes motifs, might be a suitable skeleton for the discovery of the new material molecules and drug with unique functions and properties. However, how to modular synthesis these kinds of compounds is still challenging. Herein, a chemo- and stereo-selective Rh(II)-catalyzed [1,4]-acyl rearrangements of α-diazo carbonyl compounds and thioesters has been developed, providing a modular strategy to a library of 63 tetrasubstituted vinyl sulfides. In this transformation, the yield is up to 95% and the turnover number is up to 3650. The mechanism of this reaction is investigated by combining experiments and density functional theory calculation. Moreover, the “aggregation-induced emission” effect of tetrasubstituted vinyl sulfides were also investigated, which might useful in functional material, biological imaging and chemicalnsing via structural modification.

Quantum Chemical and Experimental Studies of an Unprecedented Reaction Pathway of Nucleophilic Substitution of 2-Bromomethyl-1,3-thiaselenole with 1,3-Benzothiazole-2-thiol Proceeding Stepwise at Three Different Centers of Seleniranium Intermediates.

The results of quantum chemical and experimental studies of the reaction of 2-bromomethyl-1,3-thiaselenole with 1,3-benzothiazole-2-thiol made it possible to discover the unprecedented pathway of this reaction, which proceeds stepwise at three different centers of seleniranium intermediates. The first stage includes an attack of thiolate anion at the selenium atom of the seleniranium cation accompanied by ring opening with the formation of (Z)-2-[(1,3-benzothiazol-2-ylsulfanyl)selanyl]ethenyl vinyl sulfide, which is converted to six-membered heterocycle, 2-(2,3-dihydro-1,4-thiaselenin-2-ylsulfanyl)-1,3-benzothiazole, in a 99% yield. The latter compound undergoes rearrangement with ring contraction producing five-membered heterocycle, 2-[(1,3-thiaselenol-2-ylmethyl)sulfanyl]-1,3-benzothiazole, in a 99% yield (the thermodynamic product). The formation of 1,2-bis[(Z)-2-(vinylsulfanyl)ethenyl] diselenide is the result of the disproportionation of (Z)-2-[(1,3-benzothiazol-2-ylsulfanyl)selanyl]ethenyl vinyl sulfide. Thus, based on the quantum chemical and experimental studies, a regioselective synthesis of the reaction products in high yields was developed.

Recyclable Gold Catalyst for the Stereoselective Thioallylation of Alkynes.

The heterogeneous gold(I)-catalyzed stereoselective thioallylation of electron-deficient alkynes with allyl sulfides has been achieved by using an MCM-41-immobilized sterically demanding NHC-gold(I) complex [MCM-41-IPrAuNTf2] as the catalyst under mild conditions, delivering a wide variety of stereodefined tri- and tetrasubstituted functionalized vinyl sulfides in good to excellent yields. The new heterogeneous MCM-41-IPrAuNTf2 catalyst exhibits an activity comparable to a homogeneous IPrAuNTf2 complex and can be recovered via a simple filtration process and reused for at least seven consecutive cycles without any apparent loss of its catalytic activity and selectivity.

BF3-catalyzed oxa-Diels–Alder reaction of ethyl vinyl sulfide and β-methyl-α-phenylacrolein: a molecular electron density theory study

BF3-catalyzed oxa-Diels–Alder reaction of ethyl vinyl sulfide and β-methyl-α-phenylacrolein: a molecular electron density theory study

Recovery of Pd(II) in chloride solutions by solvent extraction with new vinyl sulfide ploymer extractants

Unlike sulfur-containing extractants, extraction efficiency of extractants containing N atoms is often affected by the concentration of H+, but strong affinity of sulfur to Pd(II) may cause stripping process not smoothly. Since sulfur atom conjugated with CC decreases electron cloud density on S atom, a novel polymer extractant containing vinyl sulfide motifs (Poly-EDDYPF) was designed and prepared in this paper, the investigation of this acid resistant extractant shows that the polymer has high extraction efficiency of Pd(II) over 99% with nicely acid resistant. The loading experiment shows that the capacity of Pd(II) of Poly-EDDYPF is up to 268 mg/g. Nearly 95.6% Pd(II) in loaded organic phase could be easily stripped using acid thiourea solution (1 mol/L HCl + 0.1 mol/L thiourea) and the organic phrase could be reused at least 5 cycles without significant decrease of the extraction efficiency. The optimized conditions for the extraction process are given: [HCl] =1 mol/L, contact time = 20 min, amount of extractant =0.7 g/L, O/A ratio = 1/1. H+ concentration and Cl – concentration exhibit practically no effect on extraction efficiency.

Computational Design of Radical Recognition Assay with the Possible Application of Cyclopropyl Vinyl Sulfides as Tunable Sensors.

The processes involving the capture of free radicals were explored by performing DFT molecular dynamics simulations and modeling of reaction energy profiles. We describe the idea of a radical recognition assay, where not only the presence of a radical but also the nature/reactivity of a radical may be assessed. The idea is to utilize a set of radical-sensitive molecules as tunable sensors, followed by insight into the studied radical species based on the observed reactivity/selectivity. We utilize this approach for selective recognition of common radicals—alkyl, phenyl, and iodine. By matching quantum chemical calculations with experimental data, we show that components of a system react differently with the studied radicals. Possible radical generation processes were studied involving model reactions under UV light and metal-catalyzed conditions.

Surface decorated magnetic nanoparticles with Mn-porphyrin as an effective catalyst for oxidation of sulfides

Mn-porphyrin complex was anchored coordinatively to silica-coated surface of magnetic nanoparticles (SMNP). Afterward, a heterogeneous nanocatalyst (Fe3O4@SiO2-MnTCPP) has been characterized by Fourier transform infrared (FT-IR), ultraviolet-visible (UV-vis) spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometry (VSM), thermogravimetric analysis (TGA), and transmission electron microscope (TEM). A thermal stability up to around 350[Formula: see text]C was verified for prepared nanocatalyst based on thermogravimetric analysis. Finally, the catalytic performance of magnetically recoverable Mn-catalyst was exploited in the green oxidation of different sulfides with urea hydrogen peroxide (UHP) in the presence of imidazole as co-catalyst in ethanol under heterogeneous conditions. The eco-friendly property of ethanol strongly induced us to employ it as the reaction solvent in this oxidation system. Complete conversion ([Formula: see text]99) of sulfides to the corresponding sulfoxide or sulfones was obtained for ethyl phenyl sulfide, phenyl vinyl sulfide, diallyl sulfide, thiocyanatoethane, 2-ethyl mercaptoethanol and tetrahydrothiophene. Moreover, the recovered catalysts keep constant conversion yield up to at least three cycles.

Electrochemical Oxidation Cross Dehydrogenative Coupling of Enamines and Thiophenols for the Synthesis of Vinyl Sulfides

AbstractA direct electrochemical oxidative cross dehydrogenative coupling reaction between enamines and thiophenols has been demonstrated. This strategy provides an effective, more economical, and environmentally friendly method to construct the C(sp2)‐S bond in the absence of chemical oxidants and transition metal catalysts. A variety of enamines and (hetero)aryl thiols are compatible with this transformation to afford the corresponding vinyl sulfides in moderate to excellent yields under undivided electrolytic cell conditions.

Cs2CO3-Promoted Hydrothiolation of Alkynes with Aryl Thioureas: Stereoselective Synthesis of (Z)-Vinyl Sulfides.

A metal-free Cs2CO3-promoted hydrothiolation of alkynes with aryl thioureas for stereoselective synthesis of (Z)-vinyl sulfides has been reported. Vinyl thioethers were obtained without a metal catalyst in good yields via anti-Markovnikov and cis addition. The protocol features a broad substrate scope of the starting materials, high atom economy, good yields, and exclusive stereoselectivity, showing potential synthetic value for the synthesis of a diversity of (Z)-vinyl thioethers.

Aldehyde to Ketone Homologation Enabled by Improved Access to Thioalkyl Phosphonium Salts.

Phosphines were previously unusable as Pummerer-type nucleophiles due to competing redox chemistry with sulfoxides. Here we circumvent this problem to achieve a formal phosphine Pummerer reaction that offers thioalkyl phosphonium salts that, in turn, give rise to diverse vinyl sulfides via Wittig olefinations. Thirty vinyl sulfides are thus prepared from (alkylthioalkyl)triphenyl phosphonium salts and aldehydes. The hydrolysis of these vinyl sulfides offers an efficient and versatile two-step one-carbon homologation of aldehydes to ketones.

ESI-MS Analysis of Thiol-yne Click Reaction in Petroleum Medium.

Petroleum contains a large number of heteroatomic compounds, but today, most of them are not efficiently utilized. The constant development of the sustainability concept recalls for rethinking the usage of fossil resources with improved chemical utility. In order to initiate research aimed at involving active petroleum compounds in chemical transformations, a new analytical method for product detection is needed. Here, we study the click reaction of thiols with alkynes, leading to the formation of α-vinyl sulfides directly in the petroleum environment. The reaction was carried out using an (IMes)Pd(acac)Cl catalyst, which demonstrated tolerance to petroleum components. In this study, the concentration of thiols ranged from 1 M to 0.01 M (from 8% to 0.1%). To detect products at low concentrations, a special alkyne labeled with an imidazole moiety was used. This approach made it possible to observe the formation of vinyl sulfides by electrospray ionization mass spectrometry (ESI-MS), which provides an opportunity for further optimization of the reaction conditions and future developments for the direct involvement of oil components in chemical reactions.

Solar light active flexible activated carbon cloth‐based photocatalyst for Markovnikov‐selective radical‐radical cross‐coupling of S‐nucleophiles to terminal alkyne and liquefied petroleum gas sensing

AbstractSelective radical‐radical coupling of terminal alkynes and thiol has been broadly used in chemical synthesis, providing plausible entries to the formation of anti‐Markovnikov products. Because of the selective control and Kharasch effect, the formation of Markovnikov products still remains an immense challenge. Herein, we designed a covalent organic polymer, poly(naphthalene 1,4,5,8‐tetracarboxylic dianhydrideimide‐benzoquinone) through in situ polymerization on activated flexible carbon cloth to function as a light harvester material for selective Markovnikov radical‐radical coupling of terminal alkynes and thiol. Mechanistic explorations verified that cross‐coupling between radical of terminal alkynes and thiol might be the key route in this organic transformation, such as C—S bond formation. This selective radical‐radical Markovnikov of cross‐coupling protocol provide an opportunity to assist the synthesis of valuable vinyl sulfide. Additionally, the synthesized material has been explored as liquefied petroleum gas (LPG) sensor for 0.5, 1.0, 1.5, and 2.0 vol% LPG, respectively. At 2.0 vol% LPG, it shows maximum sensor response as 635.29. Least response and recovery times are 2.44 and 1.0 s, respectively.

In Situ Prepared Solar Light-Driven Flexible Actuated Carbon Cloth-Based Nanorod Photocatalyst for Selective Radical-Radical Coupling to Vinyl Sulfides.

A global challenge faced by light harvesting photocatalyst is how to promote the selective organic transformation, such as C-S bond formation via radical-radical coupling under solar light. Here, we report a two-dimensional covalent organic frameworks (2D-COFs), poly (perylene-imide-benzoquinone) nanorod through insitu condensation on flexible activated carbon cloth (PPIBNR-FACC) to function as a light harvester material for highly selective radical-radical coupling to vinyl sulfides (i.e. C-S bond activation). Such a structure supports charge transfer from PPIBNR to FACC, which is essential for the selective radical-radical coupling. Hence, organic transformation is attaining high yields and selectivity (˜99%) under solar light using insitu prepared PPIBNR-FACC photocatalyst. The structural virtues of PPIBNR-FACC will trigger the utmost investigations into designable and versatile 2D-COFs for fine chemical synthesis.

Determination of Bioactive Compounds and Antimicrobial Capabilities of Purified Nymphaea lotus Linn. (Nymphaeaceae) Extract to Multidrug Resistant Enteric Bacteria

The increase in multidrug resistance bacteria is a major issue of concern to researchers and healthcare experts. There is a continuous effort by the researchers to innovate new methods of prevention and treatment of infections caused by multidrug resistance bacteria. The occurrence of bioactive compounds and antimicrobial capabilities of Nymphaea lotus Linn. (Nymphaeaceae) extract against multidrug resistant enteric bacteria were studied by assessing in-vitro antibacterial properties of the extract using agar well diffusion technique. Fourier Transform Infrared Spectrophotometer (FTIR) spectra revealed the presence of thirty (30) functional groups in purified ethanol extract of N. lotus root. Also, Gas Chromatography-Mass Spectrophotometry revealed the presence of different bioactive compounds (5-Nonanol, 2-Pentanone, 4-hydroxy-4-methyl-, Azulene, Tetradecanoic acid, 2-Chloroethyl vinyl sulfide, Decanoic acid, ethyl ester, Phytol, 1-Hexadecyne, 2-octenoic acid, Methyl-n-hexadecyl ketone, Hexadecanoic acid, methyl ester, and n-Hexadecanoic acid) in purified ethanol extract of N. lotus root which can be used in production of antimicrobial drugs. Five fractions of purified ethanol extract of N. lotus root (fraction 3-7) had significant zone of inhibition. Fraction four had the highest zone of inhibition 23.67 ± 0.88 mm while fraction seven had the least zone of inhibition 2.67 ± 1.33 mm.

Efficient Regioselective Synthesis of Novel Water-Soluble 2H,3H-[1,4]thiazino[2,3,4-ij]quinolin-4-ium Derivatives by Annulation Reactions of 8-quinolinesulfenyl Halides.

Regioselective synthesis of novel 2H,3H-[1,4]thiazino[2,3,4-ij]quinolin-4-ium derivatives has been developed by annulation reactions of 8-quinolinesulfenyl halides with vinyl chalcogenides (vinyl ethers, divinyl sulfide, divinyl selenide and phenyl vinyl sulfide) and tetravinyl silane. The novel reagent 8-quinolinesulfenyl bromide was used in the annulation reactions. The influence of the substrate structure and the nature of heteroatoms on the direction of the reactions and on product yields has been studied. The opposite regiochemistry was observed in the reactions with vinyl chalcogenides and tetravinyl silane. The obtained condensed heterocycles are novel water-soluble functionalized compounds with promising biological activity.

Application and Analysis of 6-Mercaptopurine Nanomedicine in the Treatment of Leukemia.

As a first-line drug widely used in the treatment of leukemia, 6-MP has obvious effects on leukemia. However, 6-MP disadvantages such as poor solubility in water, easy binding with serum proteins, short circulation time, and large toxic and side effects greatly limit the application of 6-MP. For this reason, various 6-MP nano drug-loading systems have been designed to increase the water solubility of 6-MP, extend the circulation time, and increase the bioavailability of 6-MP to a certain extent, reducing its toxic and side effects. However, its therapeutic effect in vivo and in vitro is still far from expectations, and there is a lot of room for improvement. In order to solve the above problems encountered in the clinical application of 6-MP, we have tried two ways of polymer prodrugs and drug-loaded vesicles to achieve efficient targeted delivery and treatment of 6-MP. We designed hyaluronic acid (HA)-based gluteal-skin-responsive 6-MP polymer prodrug (HA-GS-MP) for highly effective targeted therapy of acute myeloid leukemia. Hyaluronic acid is a natural polysaccharide, which has excellent biocompatibility and biodegradability, and has a good ability to actively target malignant tumor cells overexpressing the CD44 receptor. 6-MP is connected to the HA chain through a vinyl sulfide bond, which is stable under physiological conditions (no drug release), and under intracellular reducing conditions, the connection bond is broken and 6-MP is quickly released. HA-GS-MP has a simple preparation process, good water solubility, long cycle time, and strong targeting ability. This GSH-responsive CD44 targeted 6-MP polymer prodrug is expected to improve the therapeutic effect on acute myeloid leukemia cells.

Review on garlic creeper-Mansoa alliacea (Lam.) A.H. Gentry (Bignoniaceae)

Mansoa alliacea (Lam.) A. H. Gentry belonging to the family Bignoniaceae, commonly called as ‘Garlic vine’ and or ‘false garlic’. Is a native plant used by the Indigenous Indian tribes of the Amazon areas and has great ancestral value for the local communities and also part of the traditional medicine due to the presence of several constituents with important pharmacological properties. In folk medicine treatments M. alliacea is widely used for many diseases like cold, as an aid to fertility, commonly added to baths to treat feverish conditions, flu, body aches, cramps, fatigue, mosquito and snake repellent, epilepsy, uterine disorders, etc. Plant consist of includes diallyl disulphide, diallyl trisulphide, alliin, allicin, propyl allyl, divinyl sulfide, diallyl sulfide, dimethyl sulfide, daucosterol, beta-sitosterol, fucosterol, stigmasterol, iridoides and isothiocyanates, naphthoquinones, alkaloids, saponins, flavones. M. alliacea pharmacological activities are antioxidant, antibacterial, antifungal, anti-inflammatory, larvicidal, anti-plasmodial, etc. This review article compiled the ethnobotanical and phytopharmacological properties of M. alliacea.

Sodium iodide-mediated synthesis of vinyl sulfides and vinyl sulfones with solvent-controlled chemical selectivity.

Vinyl sulfides and vinyl sulfones are ubiquitous structures in organic chemistry because of their presence in natural and biologically active compounds and are very frequently encountered structural motifs in organic synthesis. Herein we report an efficient synthesis of vinyl sulfides and vinyl sulfones via transition metal-free sodium iodide-mediated sulfenylation of alcohols and sulfinic acids with solvent-controlled selectivity.

Synthesis of vinyl iodide chain-end polymers via organocatalyzed chain-end transformation.

In the presence of alkynes (CH[triple bond, length as m-dash]C-R2), iodide chain-end polymers (Polymer-I) were successfully transformed to vinyl iodide chain-end polymers (polymer-CH[double bond, length as m-dash]CR2-I) in a single step via organocatalysis. This reaction is completely metal-free and easy to carry out without using special reagents or special conditions. The polymers encompassing polyacrylates and polymethacrylate, and additional functionalities (e.g., OH and CF3) were also incorporated into the R2 moiety. The obtained Polymer-CH[double bond, length as m-dash]CR2-I further served as a useful precursor for copper-catalyzed cross-coupling reactions with various thiols (R3-SH) to yield vinyl sulfide chain-end polymers (polymer-CH[double bond, length as m-dash]CR2-SR3) with various R3 moieties. Interestingly, under selected conditions, this organocatalysis also offered block-like copolymers containing a conjugated oligo-alkyne segment and a non-conjugated polyacrylate segment. Exploiting the unique structure, the block-like copolymer was used as an efficient dispersant of carbon nanotubes.