- Solvent free, palladium catalyzed highly facile synthesis of diaryl disulfides from aryl thiols
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An efficient solvent free Pd(pCH2S)2dba catalyzed green-chemical strategy for the synthesis of diaryl disulfides from aryl thiols in moderate to excellent yield is reported. Variety of diaryl disulfides were synthesized. The catalyst
- Dutta, Pratip Kumar,Majumder, Arpi,Dutta, Sanjay,Dhar, Basab Bijayi,Munshi, Parthapratim,Sen, Subhabrata
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Read Online
- Solvent- and metal-free selective oxidation of thiols to disulfides using I2/DMSO catalytic system
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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.
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Read Online
- Synthesis of conformationally-restricted boropeptide thrombin inhibitors
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A series of boropeptide thrombin inhibitors was prepared in which the P3 residues of 2 (Ac)-(D)-Phe-Pro-boroLys OH · HCl) and 3 (3-phenylpropionyl-Pro-boroLys-OH · HCl) were replaced by conformationally-restricted, benzoic acid-derived residues 4. The pot
- Cacciola,Fevig,Alexander,Brittelli,Kettner,Knabb,Weber
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Read Online
- Dimsyl Anion Enables Visible-Light-Promoted Charge Transfer in Cross-Coupling Reactions of Aryl Halides
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A methodology is reported for visible-light-promoted synthesis of unsymmetrical chalcogenides enabled by dimsyl anion in the absence of transition-metals or photoredox catalysts. The cross-coupling reaction between aryl halides and diaryl dichalcogenides proceeds with electron-rich, electron-poor, and heteroaromatic moieties. Mechanistic investigations using UV-Vis spectroscopy, time-dependent density functional theory (TD-DFT) calculations, and control reactions suggest that dimsyl anion forms an electron-donor-acceptor (EDA) complex capable of absorbing blue light, leading to a charge transfer responsible for generation of aryl radicals from aryl halides. This previously unreported mechanistic pathway may be applied to other light-induced transformations performed in DMSO in the presence of bases and aryl halides.
- Pan, Lei,Cooke, Maria Victoria,Spencer, Amara,Laulhé, Sébastien
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supporting information
p. 420 - 425
(2021/11/01)
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- Preparation method of symmetric disulfide bond-containing compound
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The method comprises the following steps: adding a raw material and an oxidant to a reaction bottle containing a solvent; reacting 23W - 85W under the irradiation of 12 - 24h energy-saving lamps; and purifying the reaction product to obtain symmetrical disulfide bond-containing compounds. The raw material is mercaptan or thiophenol. The oxidizing agent is trichlorobromomethane, and the solvent is tetrahydrofuran. The method has the advantages of simple operation, high yield (70 - 90%), wide applicability, cheap and easily available raw materials, and provides a better way for the synthesis and production of symmetrical disulfide bond-containing compounds.
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Paragraph 0020; 0051-0053
(2021/11/21)
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- Synthesis and biological evaluation of disulfides as anticancer agents with thioredoxin inhibition
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Altered redox homeostasis as a hallmark of cancer cells is exploited by cancer cells for growth and survival. The thioredoxin (Trx), an important regulator in maintaining the intracellular redox homeostasis, is cumulatively recognized as a promising target for the development of anticancer drugs. Herein, we synthesized 72 disulfides and evaluated their inhibition for Trx and antitumor activity. First, we established an efficient and fast method to screen Trx inhibitors by using the probe NBL-SS that was developed by our group to detect Trx function in living cells. After an initial screening of the Trx inhibitory activity of these compounds, 8 compounds showed significant inhibition activity against Trx. We then evaluated the cytotoxicity of these 8 disulfides, compounds 68 and 69 displayed high cytotoxicity to HeLa cells, but less sensitive to normal cell lines. Next, we performed kinetic studies of both two disulfides, 68 had faster inhibition of Trx than 69. Further studies revealed that 68 led to the accumulation of reactive oxygen species and eventually induced apoptosis of Hela cells via inhibiting Trx. The establishment of a method for screening Trx inhibitors and the discovery of 68 with remarkable Trx inhibition provide support for the development of anticancer candidates with Trx inhibition.
- Wei, Xiangxu,Zhong, Miao,Wang, Song,Li, Lexun,Song, Zi-Long,Zhang, Junmin,Xu, Jianqiang,Fang, Jianguo
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- Forging C?S(Se) Bonds by Nickel-catalyzed Decarbonylation of Carboxylic Acid and Cleavage of Aryl Dichalcogenides
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A nickel-catalyzed decarbonylation of carboxylic acids cross-coupling protocol has been developed for the straightforward C?S(Se) bond formation. This reaction is promoted by a commercially-available, user-friendly, inexpensive, air and moisture-stable nickel precatalyst. Various carboxylic acids and a wide range of aryl dichalcogenide substrates were tolerated in this process which afforded products in good to excellent yields. In addition, the present reaction can be conducted on gram scale in good yield.
- Zhou, Jing-Ya,Zhu, Yong-Ming
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p. 2452 - 2461
(2021/06/28)
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- Methoxy-substituted phenylenesulfide polymer with excellent dispersivity of TiO2nanoparticles for optical application
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Oxidative polymerization of bis(2-methoxyphenyl) disulfide using a VO(acac)2-strong acid catalyst with O2 or DDQ as an oxidant gave poly(2-methoxy-1,4-phenylenesulfide), which was linear with a molecular weight of Mw = 6.0 × 103, and yet totally amorphous
- Oyaizu, Kenichi,Watanabe, Seigo
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p. 1287 - 1292
(2020/11/30)
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- Visible-light photocatalytic selective aerobic oxidation of thiols to disulfides on anatase TiO2
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This work presents the visible-light photocatalytic selective oxidation of thiols to disulfides with molecular oxygen (O2) on anatase TiO2. The high specific surface area of anatase TiO2 proved to be especially critical in
- Xu, Hui,Shi, Ji-Long,Lyu, Shaoshuai,Lang, Xianjun
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p. 1468 - 1473
(2020/04/29)
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- TEMPO visible light photocatalysis: The selective aerobic oxidation of thiols to disulfides
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TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) is well-established in orangocatalysis that usually work in synergy with transition-metal catalysis or semiconductor photocatalysis. Here, TEMPO was turned into a visible light photocatalyst to conduct the selective aerobic oxidation of thiols into disulfides. With O2 as an oxidant, a mild and efficient protocol for the selective oxidation of thiols into disulfides including symmetrical and unsymmetrical ones with 5 molpercent of TEPMO as a photocatalyst was developed at room temperature under the irradiation of 460 nm blue LEDs. It was found that a complex formed between TEMPO and thiols underpinned the visible light activity and disulfides were obtained in very high isolated yields. This work suggests that TEMPO takes diverse roles in for photocatalytic selective oxidative transformations with O2 as the oxidant.
- Xu, Hui,Zhang, Yu-Fei,Lang, Xianjun
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supporting information
p. 1520 - 1524
(2019/12/09)
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- Extended Pummerer fragmentation mediated by carbon dioxide and cyanide
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Pummerer rearrangement reactions generate sulfur (II) oxidation state from sulfur (IV) starting materials in the presence of activating reagents. We found unprecedented transformation of vinyl sulfoxide; disulfide formation reactions mediated by atmospheric pressure of carbon dioxide in extended Pummerer rearrangement reactions. Only under CO2 atmosphere, we observed moderate to high yields of disulfide starting from sulfur (IV) starting materials. Investigations on the reaction mechanism revealed that the degradation of the starting materials and the products was significant in the absence of CO2. Further evidence for the suggested reaction mechanism was obtained by a cross-over experiment and a radical trapping reagent.
- Liu, Jian,Kragh, Rasmus R.,Kamounah, Fadhil S.,Lee, Ji-Woong
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- Synthesis and nano-Pd catalyzed chemoselective oxidation of symmetrical and unsymmetrical sulfides
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A highly chemoselective, efficient and nano-Pd catalyzed protocol for the rapid construction of sulfoxides and sulfones via the oxidation of symmetrical and unsymmetrical sulfides using H2O2 as an oxidant has been developed, respectively. The ready availability of starting materials, easy recovery and reutilization of the catalyst, wide substrate scope, and high yields make this protocol an attractive alternative. The process also involves the metal-free and microwave-promoted synthesis of symmetrical diarylsulfides, and FeCl3-mediated preparation of symmetrical diaryldisulfides through the reaction of arenediazonium tetrafluoroborates with Na2S·9H2O as a sulfur source. In addition, unsymmetrical sulfides were generated via the K2CO3-mediated reaction of arenediazonium tetrafluoroborates with symmetrical disulfides.
- Li, Xing,Du, Jia,Zhang, Yongli,Chang, Honghong,Gao, Wenchao,Wei, Wenlong
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p. 3048 - 3055
(2019/03/21)
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- Biocatalytic synthesis of diaryl disulphides and their bio-evaluation as potent inhibitors of drug-resistant Staphylococcus aureus
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Staphylococcus aureus is a WHO Priority II pathogen for its capability to cause acute to chronic infections and to resist antibiotics, thus severely impacting healthcare systems worldwide. In this context, it is urgently desired to discover novel molecules to thwart the continuing emergence of antimicrobial resistance. Disulphide containing small molecules has gained prominence as antibacterials. As their conventional synthesis requires tedious synthetic procedure and sometimes toxic reagents, a green and environmentally benign protocol for their synthesis has been developed through which a series of molecules were obtained and evaluated for antibacterial activity against ESKAPE pathogen panel. The hit compound was tested for cytotoxicity against Vero cells to determine its selectivity index and time-kill kinetics was determined. The activity of hit was determined against a panel of S. aureus multi-drug resistant clinical isolates. Also, its ability to synergize with FDA approved drugs was tested as was its ability to reduce biofilm. We identified bis(2-bromophenyl) disulphide (2t) as possessing equipotent antimicrobial activity against S. aureus including MRSA and VRSA strains. Further, 2t exhibited a selectivity index of 25 with concentration-dependent bactericidal activity, synergized with all drugs tested and significantly reduced preformed biofilm. Taken together, 2t exhibits all properties to be positioned as novel scaffold for anti-staphylococcal therapy.
- Saima,Soni, Isha,Lavekar, Aditya G.,Shukla, Manjulika,Equbal, Danish,Sinha, Arun K.,Chopra, Sidharth
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p. 171 - 178
(2019/01/04)
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- Unsymmetrical Disulfide Synthesis through Photoredox Catalysis
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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
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supporting information
p. 3020 - 3025
(2018/08/23)
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- An Organodiselenide with Dual Mimic Function of Sulfhydryl Oxidases and Glutathione Peroxidases: Aerial Oxidation of Organothiols to Organodisulfides
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A novel organodiselenide, which mimics sulfhydryl oxidases and glutathione peroxidase (GPx) enzymes for oxidation of thiols by oxygen and hydrogen peroxide, respectively, into disulfides has been presented. The developed catalyst oxidizes an array of organothiols into respective disulfides in practical yields by using aerial O2 to avoid any reagents/additives, base, and light source. The synthesized diselenide also catalyzes the reduction of hydrogen peroxide into water by following the GPx enzymatic catalytic cycle with a reduction rate of 49.65 ± 3.7 μM·min-1.
- Rathore, Vandana,Upadhyay, Aditya,Kumar, Sangit
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supporting information
p. 6274 - 6278
(2018/10/05)
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- A Novel Method for the Direct Synthesis of Symmetrical and Unsymmetrical Sulfides and Disulfides from Aryl Halides and Ethyl Potassium Xanthogenate
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An efficient and new method for the synthesis of disulfides and sulfides via the reaction of aryl halides with ethyl potassium xanthogenate in the presence of MOF-199 is described. O -Ethyl- S -aryl carbonodithioate has a key role as an intermediate in this procedure; it was converted into symmetrical diaryl disulfides in DMF. Additionally, this could be applied to the synthesis of unsymmetrical aryl alkyl(aryl′) disulfides by the reaction with S -alkyl(aryl) sulfurothioates (Bunte salts) as well as unsymmetrical aryl alkyl(aryl′) sulfides in DMSO.
- Soleiman-Beigi,Arzehgar
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supporting information
p. 986 - 992
(2018/02/09)
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- Amphiphilic Molecular Motors for Responsive Aggregation in Water
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The novel concept of amphiphilic molecular motors that self-assemble into responsive supramolecular nanotubes in water is presented. The dynamic function of the molecular motor units inside the supramolecular assemblies was studied using UV-vis absorption
- Van Dijken, Derk Jan,Chen, Jiawen,Stuart, Marc C. A.,Hou, Lili,Feringa, Ben L.
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supporting information
p. 660 - 669
(2016/02/05)
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- An efficient and convenient method for the preparation of disulfides from thiols using oxygen as oxidant catalyzed by tert-butyl nitrite
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An efficient and convenient tert-butyl nitrite-catalyzed selective aerobic oxidation of thiols has been developed. Under the optimal reaction conditions, a number of thiol derivatives including aromatic thiols, heteroaromatic thiols and aliphatic thiols can be converted into their corresponding disulfides in good to excellent yields.
- Yi, Shan-Li,Li, Mei-Chao,Hu, Xin-Quan,Mo, Wei-Min,Shen, Zhen-Lu
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p. 1505 - 1508
(2016/09/23)
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- Visible-light-mediated facile synthesis of disulfides using reusable TiO2/MoS2nanocomposite photocatalyst
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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
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supporting information
p. 1268 - 1274
(2016/08/16)
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- Method for preparing disulfide bond containing compound by using TEMPO catalyst through aerobic oxidation
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The invention discloses a method for preparing a disulfide bond containing compound by using a TEMPO catalyst through aerobic oxidation. The method comprises the following steps: adding R-SH, R'-SH and TEMPO into a solvent, and performing heating reflux in an aerobic environment, thereby preparing R-S-S-R'. The method achieves oxidative coupling reaction of thiophenol and mercaptan in the absence of transition metal and is high in yield, good in selectivity and free of over-oxidized product; for aliphatic mercaptan which is relatively poor in activity, the problem of oxidation can be solved by adding copper salt as a promoter, the yield is relatively high, and the reaction is greatly affected by a substitute group; the catalyst is easy to obtain, the reaction condition is gentle, and the method is applicable to large-scale production.
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Paragraph 0044; 0045; 0046; 0048; 0109; 0110; 0111; 0112
(2016/10/07)
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- Oxidative dehydrogenation of thiols to disulfides at room temperature using silica supported iron oxide as an efficient solid catalyst
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Selective transformation of thiols to disulfides by means of oxidative dehydrogenation has been described using silica supported iron oxide under base- and solvent-free reaction conditions at room temperature in an open atmosphere. The easiness of catalyst preparation, green reaction conditions, easy separation of the formed products and catalyst from the reaction mixture, and recyclability of the catalyst, are the most attractive facets of our synthetic procedure which, being ecofriendly, will find immense applications in academic and industrial sectors.
- Paul, Susmita,Islam
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p. 95753 - 95759
(2016/10/22)
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- Metal Organic Framework 199- Catalyzed Domino Sulfur-Coupling and Transfer Reactions: The Direct Synthesis of Symmetric Diaryl Disulfides from Aryl Halides
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Abstract: A highly porous metal–organic framework Cu3 BTC2 (copper(II)-benzene-1,3,5-tricarboxylate) that known as MOF-199 was synthesized, and characterized by common methods including, FT-IR, XRD, EDX, SEM and then used as an efficient and recyclable catalyst for the direct synthesis of symmetric organic disulfides. A variety of symmetric diaryl disulfides with high chemoselectivity can be obtained by domino reaction of aryl halides (and tosylates) and potassium 5-methyl-1,3,4-oxadiazole-2- thiolate, as the base and sulfur-transfer reagent, in the presence of MOF-199. Graphical Abstract: [Figure not available: see fulltext.]
- Soleiman-Beigi, Mohammad,Mohammadi, Fariba
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p. 1497 - 1504
(2016/07/30)
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- Metal-Free Photocatalytic Aerobic Oxidation of Thiols to Disulfides in Batch and Continuous-Flow
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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
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supporting information
p. 2180 - 2186
(2015/07/27)
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- Bovine serum albumin triggered waste-free aerobic oxidative coupling of thiols into disulphides on water: An extended synthesis of bioactive dithiobis(phenylene)bis(benzylideneimine) via sequential oxidative coupling-condensation reactions in one pot from aminothiophenol and benzaldehyde
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Bovine serum albumin (BSA) has been explored for aerobic oxidative coupling of thiols (aromatic, heterocyclic as well as aliphatic) "on water" towards formation of disulphides (SS) without using any metal/non-metal complexes, bases and additives, which renders the process environmentally benign and economically attractive with good recyclability (up to four cycles). The developed green protocol was further extended for synthesis of diallyldisulphide (DADS), an important constituent of natural occurring allicin. Among various synthesized disulphides, bis(2-aminophenyl)disulphide, obtained by oxidative coupling of 2-aminothiophenol in BSA, was further utilized for condensation with benzaldehyde in the same pot thus enabling easy access to bioactive dithiobis(phenylene)bis(benzyldeneimine). This is the first example of BSA catalysed sequential (oxidation/condensation) reaction where one SS and two CN bonds are formed solely "on water."
- Saima,Lavekar, Aditya G.,Kumar, Rajesh,Sinha, Arun K.
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p. 113 - 123
(2015/04/14)
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- Heterogeneously catalyzed direct C-H thiolation of heteroarenes
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The first general methodology for the direct thiolation of electron-rich heteroarenes was developed by employing Pd/Al2O3, a recoverable and commercially available heterogeneous catalyst, and CuCl2. This method represents an operationally simple approach for the synthesis of these valuable compounds. Preliminary mechanistic studies indicate a heterogeneous catalytic system, in which both metals play a complementary role in the formation of the thiolated products. (Hetero)genius: A general method for the direct thiolation of electron-rich heteroarenes was developed by employing Pd/Al2O3, a recoverable and commercially available heterogeneous catalyst, and CuCl2. Preliminary mechanistic studies indicate a heterogeneous active catalytic species, with the two metals playing complementary roles in the formation of the thiolated products.
- Vsquez-Cspedes, Suhelen,Ferry, Anglique,Candish, Lisa,Glorius, Frank
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supporting information
p. 5772 - 5776
(2015/06/17)
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- Deep eutectic mixture catalysed the synthesis of disulfides using Bunte salts as thiol surrogates
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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
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p. 332 - 335
(2015/08/18)
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- An efficient one-pot method for the direct synthesis of organic disulfides from aryl/alkyl halides in the presence of CuCl using morpholin-4-ium morpholine-4-carbo-dithioate
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A novel and expedient route is described for the one-pot synthesis of symmetric diaryl (dialkyl) disulfides derivatives via morpholin-4-ium morpholine-4-carbo-dithioate and aryl (alkyl) halides reactions in the presence of CuCl in an aqueous solvent system. Morpholin-4-ium morpholine-4-carbo-dithioate used as new solid, stable and easy handle sulfur Sourcage.
- Soleiman-Beigi, Mohammad,Arzehgar, Zeinab
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p. 395 - 402
(2015/06/22)
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- The direct synthesis of symmetrical disulfides and diselenides by metal-organic framework MOF-199 as an efficient heterogenous catalyst
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A highly crystalline porous copper-based metal-organic framework MOF-199 was synthesized, and characterized by several techniques, including XRD, EDX, SEM, and FT-IR. MOF-199 was used as an efficient catalyst for the one-pot and efficient synthesis of organic dichalcogenides from aryl halides (-OTs) and elemental sulfur and selenium in polyethylene glycols (PEGs). A variety of disulfides and diselenides can be obtained in good to excellent yields of up to 98% in a relatively short reaction time.
- Soleiman-Beigi, Mohammad,Yavari, Issa,Sadeghizadeh, Fatemeh
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p. 87564 - 87570
(2015/11/09)
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- Silver-mediated decarboxylative C-S cross-coupling of aliphatic carboxylic acids under mild conditions
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A silver-mediated decarboxylative C-S cross-coupling reaction of aliphatic carboxylic acid is described. This reaction occurs smoothly under mild conditions and shows good tolerance of functional groups. It provides an alternative approach for the synthesis of alkyl aryl sulfides.
- Wang, Peng-Fei,Wang, Xiao-Qing,Dai, Jian-Jun,Feng, Yi-Si,Xu, Hua-Jian
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supporting information
p. 4586 - 4589
(2015/01/08)
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- Silica: An efficient catalyst for one-pot regioselective synthesis of dithioethers
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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
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- The Chan-Lam reaction of chalcogen elements leading to aryl chalcogenides
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A copper-catalyzed chalcogenation of arylboronic acids with elemental sulfur or selenium is established, which provides diaryl disulfides or diaryl monoselenides in moderate to good yields with excellent selectivities, respectively. Moreover, after sequential reduction and coupling with aryl/alkyl iodides in one pot, unsymmetrical monosulfides were obtained in good yields.
- Yu, Jin-Tao,Guo, Huan,Yi, Yuanqiuqiang,Fei, Haiyang,Jiang, Yan
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supporting information
p. 749 - 752
(2014/04/03)
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- A mild and efficient protocol for oxidation of thiols to disulfides in water
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A novel vanadium polyoxometalate [(C7H7)(CH 3)3N]3[H3V10O 28].3H2O works as a useful oxidant for the oxidation of thiols to disulfldes in water under mild reaction conditions in an excellent yield.
- Dewan, Anindita,Bora, Utpal,Kakati, Dilip K.
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experimental part
p. 231 - 234
(2012/07/13)
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- Light-driven rotary molecular motors on gold nanoparticles
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We report the synthesis of unidirectional light-driven rotary molecular motors based on chiral overcrowded alkenes and their immobilisation on the surface of gold nanoparticles through two anchors. Using a combination of 1H and 13C N
- Pollard, Michael M.,Ter Wiel, Matthijs K. J.,Van Delden, Richard A.,Vicario, Javier,Koumura, Nagatoshi,Van Den Brom, Coenraad R.,Meetsma, Auke,Feringa, Ben L.
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supporting information; experimental part
p. 11610 - 11622
(2009/12/09)
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- Synthesising Method and Benzoxathiepine Intermediates
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The invention relates to preparing derivatives of formula (1), wherein, in particular R1 and R2, identical or different, represent a hydrogen, flourine or chlorine atom, a hydroxy group, an alkyl radical and an alkoxy radical, R
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Page/Page column 7
(2008/12/07)
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- Conversion of thiols to disulfides using a hexamethylenetetramine-bromine complex
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Hexamethylenetetramine-bromine complex, a yellow-orange, very stable homogeneous solid, affects a mild and fairly general conversion of thiols to disulfides. Copyright Taylor & Francis Group, LLC.
- Yavari, Issa,Rounaqi, Ali A.,Moradi, Loghman
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p. 2659 - 2662
(2007/10/03)
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- Use of a sacriflcial-sulfur electrode in electroorganic chemistry. V. Formation of the sequence CSSSC from S and thiols or thiolates
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At a working potential of about +2.0 V (vs SCE) the carbon-sulfur electrode is a source of the electrogenerated cation S2+. In organic media, this electrophile reacts with thiols (or thiolates) to give a mixture of polysulfides of which the trisulfide is the main product. The reaction between electrogenerated Sy2- and alkyl halides is less selective. Elsevier,.
- Do, Quang Tho,Elothmani, Driss,Simonet, Jacques,Guillanton, Georges Le
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p. 273 - 281
(2007/10/03)
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- Synthesis of Disulfides via Sulfenylation of Alkyl and Aryldithiopyridine N-Oxides
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Alkyl and aryldithiopyridine N-oxides were prepared by reaction of 2,2'-dithiopyridine-1,1'-dioxide with various thiols in high yields.Some of the mixed disulfide products could in turn be used to sulfenylate efficiently other thiols.Therefore, practical and efficient synthetic methods for both symmetrical and unsymmetrical disulfides were developed.
- Barton, Derek H. R.,Chen, Chen,Wall, G. Michael
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p. 6127 - 6138
(2007/10/02)
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- Efficient, high yield oxidation of thiols and selenols to disulphides and diselenides
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Thiols and selenols are smoothly oxidised in high yield to disulphides and diselenides by sodium perborate at room temperature.
- McKillop,Koyuncu,Krief,Dumont,Renier,Trabelsi
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p. 5007 - 5010
(2007/10/02)
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- Chemistry of Sulfenic Acids. 7. Reason for the High Reactivity of Sulfenic Acids. Stabilization by Intramolecular Hydrogen Bonding and Electronegativity Effects
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It is proposed that the reason sulfenic acids (RSOH) are so reactive and usually not isolated or even detected is that they form thiosulfinates (RS(O)SR) so readily.This is a consequence of the sulfenic acid hydrogen-bonded dimer, 1, which lowers the energy of activation for thiosulfinate formation.The stability of the few sulfenic acids that have been isolated can be explained in terms of steric, electronic, and intramolecular hydrogen-bonding effects which prevent dimer formation.The importance of these effects on the stability of simple unstable sulfenic acids was demonstrated by flash vacuum pyrolysis (FVP) and the thiosulfinate/vinyl sulfoxide ratio.A novel, high yield, rearrangement of sulfenic acid 19f to 1,3-benzothiazine 26 was observed.
- Davis, Franklin A.,Jenkins, Linda A.,Billmers, Robert L.
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p. 1033 - 1040
(2007/10/02)
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- The co-oxidation reaction of isoprene and some aromatic thiols
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The co-oxidation reaction between isoprene, some aromatic thiols and molecular oxygen is described.The product distribution, in relation to the nature of the aromatic thiol used, is examined.Steric and electronic factors are discussed.
- Laan, R. van der,Moolenaar, M.J.,Koning, H. de,Huisman, H.O.
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p. 220 - 225
(2007/10/02)
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- REACTIONS OF TETRAPHENYLANTIMONY MERCAPTIDES
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Reactions of tetraphenylantimony mercaptides, Ph4SbSC6H4Y, with electrophilic species in chlorocarbon solutions are reported.With chloromethyl methyl sulphide, allyl halides, sulphenyl halide, acyl halides, halogens, and triphenyltin chloride, ready and complete halide-mercaptide exchanges occur.No allylic rearrangement is found in the reaction with trans-PhCH=CHCH2Br.In a competition reaction for ClCH2SMe, Ph4SbSC6H5 was shown to be only slightly (ca. 1.2 times) more reactive than Ph4SbSC6H4OMe-p.The initial sulphur-containing product of reaction with p-toluenesulphonyl chloride, namely the thiosulphonate, p-MeC6H4SO2SC6H4Y, reacts further with Ph4SbSC6H4Y to produce the disulphide, (YC6H4S)2.Benzoyl peroxide and Ph4SbSC6H4 provide PhSbOCOPh and disulphide.
- Wardell, James L.,Grant, Douglas W.
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p. 121 - 130
(2007/10/02)
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- Reductive Coupling of Aromatic Sulfinate Salts to Disulfides
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A variety of aromatic sulfinate salts undergo reductive coupling to disulfides in the presence of ethyl hypophosphite.Support for the intermediacy of sulfoxy sulfones and thiosulfonates has been obtained.
- Pinnick, Harold W.,Reynolds, Michael A.,McDonald, Robert T.,Brewster, Wanda D.
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p. 930 - 932
(2007/10/02)
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- TETRAPHENYLANTIMONY MERCAPTIDES, Ph4SbSAr: THERMAL DECOMPOSITION
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The products of the thermal decomposition of Ph4SbSC6H4X (X = H, p-Me, p-OMe, o-OMe and p-Br) include XC6H4SPh, (XC6H4S)2, Ph3Sb, Ph2 and PhH.Evidence is presented to show that at least a major part of the reaction occurs via free radicals.
- Wardell, James L.,Grant, Douglas W.
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p. 345 - 352
(2007/10/02)
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