- Oxidative dual C-H thiolation of imidazopyridines with ethers or alkanes using elemental sulphur
-
Dual C-H thiolation reactions using elemental sulphur remain a challenge. This communication discloses an oxidative radical dual sp2/sp3 C-H thiolation strategy for the coupling of imidazopyridines with ethers or alkanes using elemental sulphur.
- Zhang, Jun-Rong,Liao, Yan-Yan,Deng, Jian-Chao,Feng, Kai-Ying,Zhang, Min,Ning, Yun-Yun,Lin, Zi-Wei,Tang, Ri-Yuan
-
-
Read Online
- Reactivity of hypervalent silicon and tin compounds toward electrophilic sulfur
-
Sulfuration of hypervalent complexes of silicon and tin was attempted with several electrophilic sulfur reagents for making carbon - sulfur bonds under almost neutral conditions. We provided a qualitative scale of reactivity between various hypervalent salts. Simple and practical methodologies involving non-odorous elemental sulfur were developed. It avoided the use of H2S or standardized organolithium and Grignard solutions with sulfur, under highly basic conditions. (C) 2000 Elsevier Science Ltd.
- Kerverdo, Sébastien,Fernandez, Xavier,Poulain, Sophie,Gingras, Marc
-
-
Read Online
- Photochemical metal-free aerobic oxidation of thiols to disulfides
-
Thiol oxidation to disulfides is an area of great importance in organic synthesis, both for synthetic and biological purposes. Herein, we report a mild, inexpensive and green photochemical approach for the synthesis of both symmetrical and non-symmetrical disulfides, using metal-free and environmentally friendly conditions. Utilizing phenylglyoxylic acid as the photoinitiator, common household bulbs as the light source and a simple inorganic salt as the additive, a versatile oxidation of thiols leading to products in excellent yields is described. This journal is
- Spiliopoulou, Nikoleta,Kokotos, Christoforos G.
-
supporting information
p. 546 - 551
(2021/01/28)
-
- Practical and efficient recyclable oxidative system for the preparation of symmetrical disulfides under aerobic conditions
-
An efficient and practical oxidative coupling of thiols to symmetrical disulfides is developed at room temperature under aerobic conditions. The commercially available sodium methoxide solution 30 wt. % in methanol together with the air was used as a retrievable promoter system and green oxidant, respectively, for the preparation of symmetrical disulfides. The desired products were obtained in good to high yields by an economical procedure. No overoxidation of the symmetrical disulfides was observed, and various functional groups were well tolerated in the current protocol. Moreover, the new reagent reduces the generation of hazardous waste due to its high reusability. The reaction proceeded in the absence of light, and it was not inhibited by TEMPO. Also, the low yield of TEMPO-benzyl thiol adduct was detected under these conditions. Based on our experiments, a possible mechanism was proposed in the absence and presence of TEMPO.
- Ling, Ong Chiu,Heidelberg, Thorsten,Ching, Juan Joon,Khaligh, Nader Ghaffari
-
p. 281 - 294
(2020/12/13)
-
- Application of Bulky NHC-Rhodium Complexes in Efficient S-Si and S-S Bond Forming Reactions
-
The efficient and straightforward syntheses of silylthioethers and disulfides are presented. The synthetic methodologies are based on new rhodium complexes containing bulky N-heterocyclic carbene (NHC) ligands that turned out to be efficient catalysts in thiol and thiol-silane coupling reactions. These green protocols, which use easily accessible reagents, allow obtaining compounds containing S-Si and S-S bonds in solvent-free conditions. Additionally, preliminary tests on coupling of mono- and octahydro-substituted spherosilicates with selected thiols have proved to be very promising and showed that these catalytic systems can be used for the synthesis of a novel class of functionalized silsesquioxane derivatives.
- Bo?t, Ma?gorzata,?ak, Patrycja
-
supporting information
p. 17579 - 17585
(2021/11/18)
-
- Green Aerobic Oxidation of Thiols to Disulfides by Flavin-Iodine Coupled Organocatalysis
-
Coupled catalysis using a riboflavin-derived organocatalyst and molecular iodine successfully promoted the aerobic oxidation of thiols to disulfides under metal-free mild conditions. The activation of molecular oxygen occurred smoothly at room temperature through the transfer of electrons from the iodine catalyst to the biomimetic flavin catalyst, forming the basis for a green oxidative synthesis of disulfides from thiols.
- Iida, Hiroki,Kozako, Ryo,Oka, Marina
-
supporting information
p. 1227 - 1230
(2021/06/21)
-
- Substituted o-Aminophenols as Redox-Mediators in the Thiol Oxidation to Unsymmetrical Disulfides
-
A number of substituted o-aminophenols has been investigated as redox mediators of the thiol oxidation to disulfides. The electrooxidation of o-aminophenols leads to the corresponding o-iminobenzoquinones. These compounds react with thiols in the solution with a formation of disulfides. It was established that the use of 4,6-di-tert-butyl-2-(tert-butylamino)phenol as a redox mediator can reduce the overpotential of the thiol oxidation by 0.2-1.4 V depending on the nature of the coupling thiols. The unsymmetrical disulfides with alkyl, aryl, and heteroaryl substituents were obtained as the result of the indirect electrosynthesis.
- Berberova, Nadezhda T.,Burmistrova, Daria A.,Galustyan, Andrey,Smolyaninov, Ivan V.
-
-
- Ni-Catalyzed Cross-Electrophile Coupling of Aryl Triflates with Thiocarbonates via C-O/C-O Bond Cleavage
-
A nickel-catalyzed reductive coupling of aryl triflates with thiocarbonates is reported here. Both electron-rich and -deficient aryl C(sp2)-O electrophiles as well as a class of O-tBu S-alkyl thiocarbonates are compatible with the optimized reaction conditions, as evidenced by 49 examples. The reaction also proceeds with good chemoselective cleavage of the C-O bond with regard to thioesters. This work broadens the scope of nickel-catalyzed reductive cross-electrophile coupling reactions.
- Zhu, Zhaodong,Gong, Yuxin,Tong, Weiqi,Xue, Weichao,Gong, Hegui
-
supporting information
p. 2158 - 2163
(2021/04/05)
-
- Nonheme iron-thiolate complexes as structural models of sulfoxide synthase active sites
-
Two mononuclear iron(ii)-thiolate complexes have been prepared that represent structural models of the nonheme iron enzymes EgtB and OvoA, which catalyze the O2-dependent formation of carbon-sulfur bonds in the biosynthesis of thiohistidine compounds. The series of Fe(ii) complexes reported here feature tripodal N4 chelates (LA and LB) that contain both pyridyl and imidazolyl donors (LA = (1H-imidazol-4-yl)-N,N-bis((pyridin-2-yl)methyl)methanamine; LB = N,N-bis((1-methylimidazol-2-yl)methyl)-2-pyridylmethylamine). Further coordination with monodentate aromatic or aliphatic thiolate ligands yielded the five-coordinate, high-spin Fe(ii) complexes [FeII(LA)(SMes)]BPh4 (1) and [FeII(LB)(SCy)]BPh4 (2), where SMes = 2,4,6-trimethylthiophenolate and SCy = cyclohexanethiolate. X-ray crystal structures revealed that 1 and 2 possess trigonal bipyramidal geometries formed by the N4S ligand set. In each case, the thiolate ligand is positioned cis to an imidazole donor, replicating the arrangement of Cys- and His-based substrates in the active site of EgtB. The geometric and electronic structures of 1 and 2 were analyzed with UV-vis absorption and M?ssbauer spectroscopies in tandem with density functional theory (DFT) calculations. Exposure of 1 and 2 to nitric oxide (NO) yielded six-coordinate FeNO adducts that were characterized with infrared and electron paramagnetic resonance (EPR) spectroscopies, confirming that these complexes are capable of binding diatomic molecules. Reaction of 1 and 2 with O2 causes oxidation of the thiolate ligands to disulfide products. The implications of these results for the development of functional models of EgtB and OvoA are discussed. This journal is
- Ekanayake, Danushka M.,Fischer, Anne A.,Elwood, Maya E.,Guzek, Alexandra M.,Lindeman, Sergey V.,Popescu, Codrina V.,Fiedler, Adam T.
-
p. 17745 - 17757
(2020/12/30)
-
- Cyclic telluride reagents with remarkable glutathione peroxidase-like activity for purification-free synthesis of highly pure organodisulfides
-
Monoamino cyclic tellurides with a five- or six-membered ring structure and their derivatives were developed as a new class of catalyst for the oxidation of organothiols to organodisulfides in a glutathione peroxidase-like catalytic reaction. Quantitative conversion and high reaction rate were achieved by performing the reaction in an organic-aqueous segmented microflow system. Importantly, the process circumvented product purification, which is a major limitation of current organodisulfide synthetic methods.
- Arai, Kenta,Osaka, Yuui,Haneda, Masahiro,Sato, Yuumi
-
p. 3647 - 3655
(2019/07/22)
-
- Redox Activation of Hydrogen Sulfide, Thiols, and Sulfur in Electrosynthesis of Organic Di- and Polysulfides
-
A novel and efficient method for the synthesis of biologically active organic di-, tri- and tetrasulfides has been proposed. Different methods of redox activation of sulfur, hydrogen sulfide, and thiols in the reactions with organic compounds have been considered. Electrochemical initiation of the reactions of the mediator–H2S–S8 system with cyclohexane, methylcyclohexane, and benzene has occurred to the formation of polysulfides R2Sn (n = 2–4). The application of tetrabutylammonium bromide as a mediator of H2S oxidation has allowed to decrease the anodic overpotential of electrosynthesis. Di- and tetrasulfides have been obtained under anodic activation of the cycloalkanethiols (C5, C6) or thiophenol in the reaction with sulfur. Electroreduction of S8 in the presence of the same thiols has favored the formation of di- and trisulfides. The yield and the ratio of the R5Sn (n = 2–4) depend on the method of redox activation of the thiolating reagent.
- Shinkar’,Smolyaninov,Kuzmin,Berberova
-
p. 689 - 696
(2019/06/05)
-
- A novel dual-nano assisted synthesis of symmetrical disulfides from aryl/alkyl halides
-
Here, we have reported a novel approach towards dual-nano assisted synthesis of disulfides from coupling of alkyl/aryl halides and sulfur nanoparticles. The indium oxide nanoparticles as catalyst expedite the conversion and sulfur nanoparticle notably enhances the miscibility, providing a faster, high yielding and cost-effective process in ethanol-water system. The method has synthetic advantages in terms of mild reaction framework, catalyst regeneration, and absence of any sulfide or polysulfide linkage as by-product leading to a column free synthesis. A variety of alkyl, aryl and heteroaryl symmetrical disulfides are obtained in good to excellent yields up to exceeding 98%.
- Devi, Namita,Hazarika, Sukanya,Gogoi, Prasanta,Barman, Pranjit
-
p. 1927 - 1938
(2018/07/21)
-
- Photo-induced thiol coupling and C-H activation using nanocrystalline lead-halide perovskite catalysts
-
The use of photon energy to promote chemical transformations offers versatile control of reaction kinetics and progress. Over the past decade, many photoactive transition-metal complexes and organic chromophores were developed to catalyze chemical transformations, enabling a myriad of reactions and compounds that were previously inaccessible via traditional synthetic methods. Here, we demonstrate the photocatalytic oxidative coupling of organic thiols using cesium lead halide perovskite nanocrystals as photocatalysts. The photo-catalyzed thiol coupling reactions selectively produced symmetric and unsymmetrical disulfides in high yields (68-96% isolated yields). Additionally, we discovered a perovskite-catalyzed phosphonylation of tertiary amines via visible-light-mediated cross-dehydrogenative coupling reaction, and obtained good isolated yields (50-96%). The variety of visible-light-induced photocatalytic processes that perovskite nanocrystals are capable of, coupled with their facile preparation, easily tunable redox potentials, high catalytic efficiency and reusability, presents great opportunities for their future applications in green and sustainable organic synthesis.
- Wu, Wen-Bin,Wong, Ying-Chieh,Tan, Zhi-Kuang,Wu, Jie
-
p. 4257 - 4263
(2018/08/24)
-
- Unsymmetrical Disulfide Synthesis through Photoredox Catalysis
-
A facile and eco-friendly visible light-mediated synthesis of symmetrical and unsymmetrical disulfides using tris[2-phenylpyridinato-C2,N]iridium(III) under additive and oxidant free conditions has been disclosed. The developed method is very mild, several functional group tolerant and highly atom economical requiring extremely low amount of catalyst loading (0.5 mol%). (Figure presented.).
- Dethe, Dattatraya H.,Srivastava, Aparna,Dherange, Balu D.,Kumar, B. Vijay
-
supporting information
p. 3020 - 3025
(2018/08/23)
-
- Europhtal (8020) efficiently catalyzes the aerobic oxidation of in situ generated thiols to symmetric disulfides (disulfanes)
-
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
-
-
- Conversion of organic halides to disulfanes using KCN and CS2
-
A sulfur transfer reagent was produced in situ upon stirring a mixture of KCN and CS2 in DMF at r.t. for 15 min, which after heating with an alkyl halide or aryl halide and CuI gave the corresponding symmetric dialkyl or diaryl disulfide, respectively, in high to excellent yields.
- Abbasi, Mohammad,Nowrouzi, Najmeh,Borazjani, Saeedeh Ghassab
-
p. 4251 - 4254
(2017/10/11)
-
- Reusable cobalt-phthalocyanine in water: Efficient catalytic aerobic oxidative coupling of thiols to construct S-N/S-S bonds
-
A new aerobic oxidative coupling of thiols in water to construct sulfenamides or disulfides was developed, utilizing cobalt(ii)phthalocyanine-tetra-sodium sulfonate as the catalyst and O2 as the oxidant. The mother liquor could be recycled up to 20 times with negligible loss of activity and only a minor decrease of product yield.
- Dou, Yingchao,Huang, Xin,Wang, Hao,Yang, Liting,Li, Heng,Yuan, Bingxin,Yang, Guanyu
-
supporting information
p. 2491 - 2495
(2017/07/17)
-
- Method for catalyzing molecular oxygen to oxidize into disulfides with S-S bonds in aqueous phase
-
The invention provides a method for catalyzing molecular oxygen to oxidize into disulfides with S-S bonds in an aqueous phase. The method includes taking water-soluble transition metal phthalocyanine compounds as catalysts, and enabling sulfhydryl compounds to react for 1-30 hours in the aqueous phase at a pressure of 0.01-1.00 Mpa, at 40-100 DEG C and in the presence of oxygen or air so as to obtain the disulfides with the S-S bonds. The method has the advantages that reaction is conducted in the aqueous phase, so that addition of other organic solvents is unneeded; the catalysts are high in catalytic activity, high in reaction efficiency and reusable; the method is simple in synthetic process, high in product selectivity, fewer in byproducts and wastes and environment friendly, thereby being promising in industrial application prospect.
- -
-
Paragraph 0022; 0023; 0029; 0030
(2017/08/29)
-
- Solvent- and metal-free selective oxidation of thiols to disulfides using I2/DMSO catalytic system
-
We describe herein a simple, fast and inexpensive protocol for the oxidative coupling of thiols employing a stoichiometric amount of DMSO and iodine as the catalyst. Various aromatic disulfides were obtained in good to excellent yields in short reaction times at room temperature, while aliphatic disulfides were achieved in good yields when the reactions were conducted under microwave irradiation.
- Bettanin, Luana,Saba, Sumbal,Galetto, Fábio Z.,Mike, Gustavo A.,Rafique, Jamal,Braga, Antonio L.
-
supporting information
p. 4713 - 4716
(2017/11/21)
-
- Chromium(III) and indium(III) 3,6-di-tert-butyl-o-semiquinolate complexes as redox mediators of hydrogen sulfide oxidation in reactions with cycloalkanes
-
The electrochemical oxidation of the chromium(III) and indium(III) complexes with 3,6-di-tert-butyl-o-semiquinolate leading to the formation of active monocationic species is studied by cyclic voltammetry. The reactions of the latter with hydrogen sulfide generate the radical cation of H2S, whose fragmentation affords the proton and thiyl radical. These complexes are proposed for the first time as redox mediators for the one-pot thiolation of inert cycloalkanes C6–C8, which decreases the activation energy of hydrogen sulfide compared to that for direct electrochemical oxidation. The major products of cycloalkane functionalization involving H2S are thiols and organic di- and trisulfides. The yield of the synthesized compounds depends on the type of the mediator: the chromium(III) complex exhibits the highest efficiency in the electrocatalytic transformations.
- Berberova,Shinkar,Smolyaninov,Shvetsova,Sediki
-
p. 578 - 582
(2017/09/23)
-
- Thiolation of cycloalkenes C5, C6 by redox-activation of hydrogen sulfide
-
Direct and indirect redox-activation of H2S in the presence of cyclopentene or cyclohexene in MeCN at 25?°C affords the corresponding cycloalkanethiols.
- Shinkar, Elena V.,Kudryavtsev, Daniil A.,Pashchenko, Konstantin P.,Berberova, Nadezhda T.,Okhlobystina, Alexandra V.
-
p. 180 - 182
(2017/03/30)
-
- One-pot conversion of alkyl halides to organic disulfides (disulfanes) using thiourea and hexamethyldisilazane (HMDS) in DMSO
-
A practical method to synthesize symmetric disulfides from alkyl halides has been developed. Using this procedure primary, secondary, benzylic and allylic disulfides were prepared by treating the corresponding alkyl halides with thiourea and HMDS in DMSO at 50 °C within 10-24 h in high yields.
- Abbasi, Mohammad,Jabbari, Arida
-
-
- The synthesis of symmetrical disulfides by reacting organic halides with Na2S2O3·5H2O in DMSO
-
A one-pot, and scalable method to prepare symmetric disulfides from their corresponding primary, secondary, allylic, and benzylic halides has been developed. In this method, a disulfide is synthesized by reacting an alkyl halide with Na2S2O3·5H2O at 60-70 °C in DMSO.
- Abbasi, Mohammad,Mohammadizadeh, Mohammad Reza,Saeedi, Narges
-
supporting information
p. 89 - 92
(2016/01/12)
-
- Visible-light-mediated facile synthesis of disulfides using reusable TiO2/MoS2nanocomposite photocatalyst
-
A nontoxic and inexpensive TiO2/MoS2nanocomposite was prepared and employed as an efficient photocatalyst for the synthesis of symmetrical disulfides under visible light irradiation at room temperature. Both aryl and alkyl thiols survived the reaction conditions, affording the corresponding disulfides in good to excellent yields. The photocatalyst could be easily recovered by simple centrifugation and filtration and reused several times without significant loss in its activity.
- Liu, Wenjie,Wang, Cancan,Huang, Yibo,Chen, Qun,Wang, Liang,He, Mingyang
-
supporting information
p. 1268 - 1274
(2016/08/16)
-
- Diacetoxyiodobenzene mediated oxidative transformation of thione to disulfides
-
We have developed an efficient oxidative transformation of thione to disulfides using diacetoxyiodobenzene (DIB) in acetonitrile at room temperature. This strategy is suited for oxidation of thiols to disulfide also. The present oxidation protocol is mild reaction condition, column free, and a new route for disulfide formation.
- Singh, Sarangthem Joychandra,Devi, Nepram Sushuma
-
supporting information
p. 5941 - 5943
(2016/12/07)
-
- METHOD FOR REFINING CYCLOHEXENE
-
PROBLEM TO BE SOLVED: To industrially produce cyclohexene of high quality by safely reducing cyclohexenyl hydroperoxide having a possibility of explosion. SOLUTION: Cyclohexene including cyclohexenyl hydroperoxide is brought into contact with a reducing agent to decompose the cyclohexenyl hydroperoxide and then the cyclohexene is distilled. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
- -
-
Paragraph 0030-0032
(2017/03/17)
-
- Thioetherification via Photoredox/Nickel Dual Catalysis
-
Hypervalent alkylsilicates represent new and readily accessible precursors for the generation of alkyl radicals under photoredox conditions. Alkyl radicals generated from such silicates serve as effective hydrogen atom abstractors from thiols, furnishing thiyl radicals. The reactive sulfur species generated in this manner can be funneled into a nickel-mediated cross-coupling cycle employing aromatic bromides to furnish thioethers. The serendipitous discovery of this reaction and its utilization for the thioetherification of various aryl and heteroaryl bromides with a diverse array of thiols is described. The S-H selective H atom abstraction event enables a wide range of functional groups, including those bearing protic moieties, to be tolerated. (Chemical Equation Presented).
- Jouffroy, Matthieu,Kelly, Christopher B.,Molander, Gary A.
-
supporting information
p. 876 - 879
(2016/03/04)
-
- DCDMH-promoted synthesis of thiophosphates by coupling of H-phosphonates with thiols
-
DCDMH-mediated phosphorylation of versatile thiols with H-phosphonates for the preparation of synthetically and biologically important thiophosphates was demonstrated. Without metal catalysts and other additives, phosphorylation occurred to give the desired products with good to excellent yields within 10 min at ambient temperature in the air.
- Bi, Xiaojing,Li, Junchen,Meng, Fanhua,Wang, Hongmei,Xiao, Junhua
-
supporting information
p. 706 - 711
(2016/01/15)
-
- One-pot synthesis of organic disulfides (disulfanes) from alkyl halides using sodium sulfide trihydrate and hexachloroethane or carbon tetrachloride in the poly(ethylene glycol) (PEG-200)
-
Abstract Symmetric disulfides are produced by treating their corresponding organic halides including benzylic, allylic, primary and secondary halides with Na2S·3H2O and C2Cl6 or CCl4 in PEG-200 at room temperature in high yields.
- Abbasi, Mohammad,Mohammadizadeh, Mohammad Reza,Moosavi, Hekmat,Saeedi, Narges
-
p. 1185 - 1190
(2015/03/31)
-
- 4,4'-Azopyridine as an easily prepared and recyclable oxidant for synthesis of symmetrical disulfides from thiols or alkyl halides(tosylates)/thiourea
-
Heterocyclic azo compounds, prepared from corresponding amines in one step, are used as effective oxidants for the conversion of thiols into symmetrical disulfides in high yields. Among the studied azo compounds, 4,4'-azopyridine was found to be very efficient for the odorless conversion of alkyl halides into disulfides in the presence of thiourea. An attractive feature of this azo compound is that its obtained solid side product hydrazine is easily separated by filtration and can be recycled to its azo compound for further use.
- Khalili, Dariush,Iranpoor, Nasser,Firouzabadi, Habib
-
p. 544 - 555
(2015/10/19)
-
- Deep eutectic mixture catalysed the synthesis of disulfides using Bunte salts as thiol surrogates
-
Bunte salts, easily prepared from odourless sodium thiosulfates and various alkyl and aryl halides, acted as thiol surrogates for preparation of disulfides in the presence of hydrogen peroxide and a Bronsted-acidic deep eutectic mixture. The reaction proceeded smoothly to give the corresponding disulfide products in moderate to good yields, leaving odourless sodium bisulfite and water as the by-products. Moreover, this catalytic system could be readily recovered and reused several times without significant loss in activity.
- Zhou, Yongsheng
-
p. 332 - 335
(2015/08/18)
-
- Fast and efficient green synthesis of thiosulfonate S-esters by microwave-supported permanganate oxidation of symmetrical disulfides
-
Potassium permanganate absorbed on copper(II) sulfate pentahydrate has been found to be an efficient, inexpensive, and green oxidation agent for the synthesis of "symmetrical" thiosulfonate S-esters by oxidation of the corresponding symmetrical disulfides. The oxidation reactions were carried out under solvent-free reaction conditions within 15 min under the influence of microwave irradiation, as well as (for comparison) supported by conventional heating, to afford yields of the thiosulfonate S-esters in the range of 60-83%. The oxidation reaction appears to proceed (at least partly) via an intermediate symmetrical vic-disulfoxide.
- Luu, Thi Xuan Thi,Nguyen, Thao-Tran Thi,Le, Thach Ngoc,Spanget-Larsen, Jens,Duus, Fritz
-
p. 340 - 350
(2015/04/27)
-
- Metal-Free Photocatalytic Aerobic Oxidation of Thiols to Disulfides in Batch and Continuous-Flow
-
Disulfides represent significant molecular and structural features in various biologically active compounds and fine chemicals. Therefore, the development of mild, efficient and sustainable methods to access disulfides is of great importance. Here, we describe the development of a mild metal-free photocatalytic aerobic oxidation of thiols to disulfides using Eosin Y and visible-light irradiation. A continuous flow procedure was developed to accelerate the photocatalytic process, enabling the preparation of disulfides with high purity in a timeframe of minutes. The mildness and applicability of our method was exemplified by the flow synthesis of the cyclic peptide hormone, oxytocin, requiring only a 200s reaction time and an efficient one-pot batch protocol for the preparation of the therapeutic thiuram disulfide, disulfiram.
- Talla, Ali,Driessen, Brian,Straathof, Natan J. W.,Milroy, Lech-Gustav,Brunsveld, Luc,Hessel, Volker,No?l, Timothy
-
supporting information
p. 2180 - 2186
(2015/07/27)
-
- TBPB-promoted metal-free synthesis of thiophosphinate/phosphonothioate by direct P-S bond coupling
-
An efficient method for the direct coupling of thiol/thiophenol with H-phosphine oxides or H-phosphinate esters is reported. Without using any metallic catalyst, the direct sulfur-phosphorus bond coupling reaction was promoted using tert-butyl peroxybenzo
- Wang, Jichao,Huang, Xin,Ni, Zhangqin,Wang, Sichang,Wu, Jun,Pan, Yuanjiang
-
supporting information
p. 314 - 319
(2018/04/16)
-
- A mild and efficient method for the conversion of aldehydes into nitriles and thiols into disulfides using an ionic liquid oxidant
-
A simple, mild and high yielding method for the conversion of various aldehydes to nitriles has been developed using an ionic liquid reagent, hexamethylene bis(N-methylimidazolium) bis(dichloroiodate) (HMBMIBDCI), in combination with aqueous ammonia in CH3CN at room temperature. Moreover, the treatment of aromatic and aliphatic thiols with HMBMIBDCI resulted in the corresponding disulfides in solvent-free condition at room temperature.
- Hosseinzadeh, Rahman,Golchoubian, Hamid,Nouzarian, Mahboobe
-
p. 4713 - 4725
(2015/06/30)
-
- Haloacid/dimethyl sulfoxide-catalyzed synthesis of symmetrical disulfides by oxidation of thiols
-
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
-
supporting information
p. 5578 - 5582
(2015/09/21)
-
- Cubic Ag2O nanoparticle incorporated mesoporous silica with large bottle-neck like mesopores for the aerobic oxidative synthesis of disulfide
-
Highly stable, environmentally benign cubic Ag2O nanoparticles dispersed on mesoporous silica with large bottle-neck like mesopores were synthesized and characterized by BET surface area analysis, HR TEM, EDX, FTIR and powder XRD studies. The Ag2O nanoparticles were homogeneously distributed having an average size of 20-40 nm. The activity of the catalyst was probed through an efficient aerobic chemoselective oxidation of thiols to disulfides in water under atmospheric oxygen as the cheapest oxidant. Alkyl, aryl and imine containing symmetrical disulfides can be easily obtained in high yields under mild reaction conditions with no over oxidized product. The efficiency of the catalyst was further demonstrated as the highly sensitive imine bond was well sustained under these mild reaction conditions. Moreover, unlike the other literature precedents, in this present work, single crystal structures of both simple symmetrical disulphide as well as imine containing disulphides are reported for the first time. The catalyst is very much water compatible and can be recycled and reused for at least five cycles. The standard leaching experiment proved that the reaction was heterogeneous with this recyclable catalyst.
- Das, Paramita,Ray, Suman,Bhaumik, Asim,Banerjee, Biplab,Mukhopadhyay, Chhanda
-
p. 6323 - 6331
(2015/02/19)
-
- Redox mediators of hydrogen sulfide oxidation in reactions with cycloalkanes
-
An indirect electrochemical method for thiolation of cycloalkanes C5-C7 has been suggested. The method is based on a new approach to activation of hydrogen sulfide by redox mediators.
- Berberova,Shinkar',Smolyaninov,Pashchenko
-
p. 295 - 298
(2016/01/12)
-
- Imidazole Promoted Highly Efficient Large-Scale Thiol-Free Synthesis of Symmetrical Disulfides in Aqueous Media
-
A highly efficient and environmentally friendly method for the imidazole promoted preparation of symmetrical organic disulfides from Bunte salts is described. This thiol-free procedure produces the desired disulfides even on a large scale by reaction of Bunte salts with imidazole in good to high yields in aqueous media.
- Mokhtari, Babak,Kiasat, Ali Reza,Monjezi, Javid
-
p. 1573 - 1579
(2015/09/15)
-
- Ultrasound-Accelerated Synthesis of Asymmetrical Thiosulfonate S-Esters by Base-Promoted Reaction of Sulfonyl Chlorides with Thiols
-
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
-
p. 1934 - 1941
(2015/12/12)
-
- Direct synthesis of disulfides from alkyl halides using thiourea and CCl4 in glycerol
-
Abstract Dialkyl disulfides were obtained on the basis of the reaction of alkyl halides and thiourea in the presence of CCl4 and Et3N. This procedure enables the odorless and one-pot synthesis of disulfides by employing cheap, easy-to-handle and readily available reagents and substrates in wet glycerol.
- Abbasi, Mohammad,Khalili, Dariush
-
p. 1425 - 1430
(2015/06/22)
-
- Graphene Oxide-Assisted One-Pot and Odorless Synthesis of Symmetrical Disulfides Using Primary and Secondary Alkyl Halides (Tosylates) and Thiourea as Sulfur Source Reagent
-
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
-
p. 1727 - 1734
(2015/12/12)
-
- Nickel ferrite nanoparticles-hydrogen peroxide: A green catalyst-oxidant combination in chemoselective oxidation of thiols to disulfides and sulfides to sulfoxides
-
Nickel ferrite nanoparticles-hydrogen peroxide has been demonstrated for the first time as a green and efficient catalyst-oxidant combination in the chemoselective oxidation of thiols to disulfides and sulfides to sulfoxides. This magnetically separable catalyst was found to be reusable for five consecutive runs without appreciable change in the activity, as well as composition of the catalyst. The mechanism for the oxidation of thiols and sulfides has also been proposed. the Partner Organisations 2014.
- Kulkarni, Aparna M.,Desai, Uday V.,Pandit, Kapil S.,Kulkarni, Makarand A.,Wadgaonkar, Prakash P.
-
p. 36702 - 36707
(2014/12/10)
-
- Silica: An efficient catalyst for one-pot regioselective synthesis of dithioethers
-
The development of a silica-promoted highly selective synthesis of 1,2 or 1,3-dithioethers via solvent-free one-pot tandem reactions of an allyl bromide with excess thiol at room temperature is described. The choice of silica gel, either pre-calcined or moistened with water, exhibited notable regioselectivity in the formation of dithioethers. Plausible mechanistic routes were explored and postulated.
- Kundu, Samir,Roy, Babli,Basu, Basudeb
-
-
- One-pot efficient synthesis of disulfides from alkyl halides and alkyl tosylates using thiourea and elemental sulfur without contamination by higher polysulfides
-
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
-
p. 201 - 205
(2013/07/26)
-
- Rapid and convenient method for the synthesis of symmetrical disulfides
-
We present here the results on the use of 1,3,5-triazo-2,4,6- triphosphorine-2,2,4,4,6,6-hexachloride as an efficient promoter in the conversion of thiols to the corresponding symmetrical disulfides under solvent-free conditions. Aromatic thiols bearing electron donating and electron withdrawing groups, heteroaromatic, and alkyl thiols reacted efficiently to afford excellent yields of disulfides in short reaction times after easy work-up. Different functional groups including carboxyl, methoxy, methylthio, and halogen are tolerated. Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional figures and tables.
- Bahrami, Kiumars,Khodaei, Mohammad M.,Shakibaian, Vida,Targhan, Homa
-
p. 981 - 988
(2013/09/02)
-
- (NH 4) 6Mo 7O 34·4H 2O as an efficient, selective, and reusable catalyst for the oxidation of thiols to disulfides using potassium bromate
-
Ammonium molybdate, (NH 4) 6Mo 7O 34·4H 2O, is found to be an efficient and selective catalyst for the oxidation of thiols to corresponding disulfides using potassium bromate in aqueous acetonitrile as the solvent. Among various solvents tested, CH3CN/H2O showed better results in terms of the reaction yield and rate. In the absence of (NH4)6Mo 7O24·4H2O, the oxidation reaction is not selective for the formation of disulfides. The catalyst can be easily recovered after completion of the reaction and reused without any significant loss of its activity. [Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional text and figures.]
- Bayraq, Samad Shoghpour,Nikseresht, Ahmad,Khosravi, Iman
-
supporting information
p. 1236 - 1243
(2013/09/23)
-
- Copper oxide nanoparticles supported on graphene oxide-Catalyzed S-arylation: An efficient and ligand-free synthesis of aryl sulfides
-
Copper oxide nanoparticles that are supported on graphene oxide as a catalytic system have been utilized for ligand-free and solvent-free C-S cross-coupling reactions with weak bases such as tri- ethylamine. Symmetrical/unsymmetrical aryl sulfides have been synthesized by the coupling of different aryl halides with aromatic as well as aliphatic sulfides. Surprisingly, aryl chlorides also well reacted with different types of sulfides in the presence of dimethyl sulfoxide and cesium carbonate. Besides, this catalytic system is suitable for the synthesis of phenothiazines via cascade C-S and C-N cross-coupling of ortho-dihalides and ortho-aminobenzothiazoles. In addition, this alternative approach is extremely useful for the synthesis of a variety of symmetrical diaryl sulfides by using thiourea as a sulfur source that is devoid of the foul smell of thiols. Indeed, the calculated E-factor value of our present protocol is 2.52. Furthermore, this protocol is particularly attractive as an environmentally benign and practical method for the synthesis of different aryl sulfides. Moreover, the heterogeneous catalytic system described in this process represents not only a greener approach but retains its significant activity for up to six catalytic cycles.
- Kamal, Ahmed,Srinivasulu, Vunnam,Murty,Shankaraiah, Nagula,Nagesh, Narayana,Reddy, T. Srinivasa,Subba Rao
-
p. 2297 - 2307
(2013/10/01)
-
- A simple and practical method for the oxidation of thiols to disulfides at mild conditions without solvents
-
A green, straightforward, and novel method for the oxidation of thiols to the corresponding disulfides is reported using hydrogen peroxide catalyzed by tetrabutylammonium iodide (TBAI) without solvents at room temperature. The corresponding disulfides were obtained with excellent yields and short reaction times. Copyright
- He, Ying,Hang, Dongliang,Lu, Ming
-
experimental part
p. 1118 - 1124
(2012/08/14)
-
- Microwave assisted oxidative coupling of thiols to symmetrical disulfides with tripropylammonium fluorochromate(VI) (TPAFC)
-
Tripropylammonium fluorochromate(VI) (TPAFC) is an efficient and novel reagent, which can be prepared easily and oxidizes thiols to the corresponding disulfides, quickly. The reactions are performed cleanly and are controlled to stop at the disulfide stage, without over-oxidation or side products. Coupling of thiols to their corresponding disulfides, was studied in solution at room temperature and under conditions using a minimal amount of solvent under microwave irradiation. The easy procedure, simple work-up, short reaction times, and excellent yields are other advantages of this reagent.
- Mohammadi, Mohammad Kazem,Ghammamy, Shahriare
-
experimental part
p. 139 - 144
(2012/04/23)
-
- Synthesis of aryl thioethers through the N -chlorosuccinimide-promoted cross-coupling reaction of thiols with Grignard reagents
-
A convenient one-pot approach for the synthesis of aryl sulfides through the coupling of thiols with Grignard reagents in the presence of N-chlorosuccinimide is described. The sulfenylchlorides were formed when thiols were treated with N-chlorosuccinimide, and the resulting sulfenylchlorides were then directly reacted with Grignard reagents to provide aryl sulfides in good to excellent yields under mild reaction conditions. Functional groups including ester, fluoro, and chloro are tolerated by the reaction conditions employed. It is important to note that this method has a short reaction time (30 min in total) and represents an alternative approach for the synthesis of aryl sulfides over the existing protocols.
- Cheng, Jun-Hao,Ramesh, Chintakunta,Kao, Hsin-Lun,Wang, Yu-Jen,Chan, Chien-Ching,Lee, Chin-Fa
-
p. 10369 - 10374
(2013/01/15)
-