- Diacetoxyiodobenzene mediated oxidative transformation of thione to disulfides
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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
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- A cerium-based metal-organic framework having inherent oxidase-like activity applicable for colorimetric sensing of biothiols and aerobic oxidation of thiols
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A cerium-based metal-organic framework (MOF; 1) with a UiO-66 (UiO: University of Oslo) framework topology was synthesized solvothermally by employing 3,4-dimethylthieno[2,3-b]thiophene-2,5-dicarboxylic acid as a ligand. The MOF was thoroughly characterized by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction, infrared spectroscopy, and thermogravimetric and N2 sorption analyses. The activated material (1′) retained its structural integrity in water, acetic acid and 1 M HCl solution. XPS investigation reveals the presence of both Ce(iii) and Ce(iv) ions in 1. Owing to the presence of mixed-valence cerium ions, 1′ was able to oxidize the chromogenic peroxidase substrate 3,3′,5,5′-tetramethylbenzidine (TMB) or 2,2′-azinobis(3-ethylbenzothizoline-6-sulfonic acid) (AzBTS) in the absence of an external oxidizing agent. Thus, it showed inherent oxidase-like catalytic properties. Inspired by the excellent oxidase-mimicking activity of 1′, a protocol was developed for the rapid colorimetric sensing of biothiols in NaAc buffer (0.2 M, pH = 4). The sensing ability of 1′ towards cysteine was also demonstrated in human blood plasma. Furthermore, the redox-active cerium ions enabled 1′ to exhibit excellent heterogeneous catalytic performance in aerobic oxidation catalysis of thiol compounds. The material is reusable (both as a sensor and as a catalyst), low-cost and highly stable, which renders it a promising candidate for the monitoring of biothiols in immunoassays and medical diagnosis as well as for industrial oxidation catalysis.
- Dalapati, Rana,Sakthivel, Balasubramanian,Ghosalya, Manoj K.,Dhakshinamoorthy, Amarajothi,Biswas, Shyam
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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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- Diaryl disulfides and thiosulfonates as combretastatin A-4 analogues: Synthesis, cytotoxicity and antitubulin activity
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Diaryl disulfides and diaryl thiosulfonates were synthesized with the two phenyl rings of all compounds bearing identical halide substituents. Because of structural similarity to the potent antimitotic natural product combretastatin A-4 (CA-4), the compounds were examined for inhibition of tubulin polymerization, and the thiosulfonates were more active than the disulfides. The nine thiosulfonates had IC50 values ranging from 1.2 to 9.1 μM, as compared with 1.3 μM obtained with CA-4. The compounds thus ranged from equipotent with CA-4 to 7-fold less active. The nine disulfides had IC50 values ranging from 1.2 to 5.1 μM, as compared with 0.54 μM obtained with CA-4. The compounds thus ranged from less than half as active as CA-4 to over 9-fold less active. The most active members of each group, 2 g and 3c, in the assembly assay were modeled into the colchicine site. Compound 3c had significant hydrophobic interactions with β-tubulin residues CYS 241 and ALA 250, and its thiosulfonate bridge made a hydrogen bond with β-tubulin residue ASN 258. Compound 2 g had hydrophobic interactions with β-tubulin residues ALA 250, CYS 241 and ALA 254, but there was no significant interaction of the disulfide bridge with tubulin.
- Bai, Ruoli,Barbosa, Euzébio Guimar?es,Beatriz, Adilson,Hamel, Ernest,Khodyuk, Rejane Gon?alves Diniz,Louren?o, Estela Mariana Guimar?es,de Lima, Dênis Pires,dos Santos, Edson dos Anjos
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- T BuOK-triggered bond formation reactions
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Recently, inexpensive and readily available tBuOK has seen widespread use in transition-metal-free reactions. Herein, we report the use of tBuOK for S-S, S-Se, NN and CN bond formations, which significantly extends the scope of tBuOK in chemical synthesis. Compared with traditional methods, we have realized mild and general methods for disulfide, azobenzenes imine etc. synthesis.
- Xu, Yulong,Shi, Xiaonan,Wu, Lipeng
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p. 24025 - 24029
(2019/08/13)
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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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- A novel dual-nano assisted synthesis of symmetrical disulfides from aryl/alkyl halides
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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
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supporting information
p. 1927 - 1938
(2018/07/21)
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- Chemoselective synthesis of diaryl disulfides via a visible light-mediated coupling of arenediazonium tetrafluoroborates and CS2
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A highly efficient and chemoselective method for the synthesis of diaryl disulfides is developed via a visible light-promoted coupling of readily accessible arenediazonium tetrafluoroborates and CS2. This practical and convenient protocol provides a direct pathway for the assembly of a series of disulfides in an environmentally friendly manner with good to excellent yields.
- Leng, Jing,Wang, Shi-Meng,Qin, Hua-Li
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supporting information
p. 903 - 909
(2017/06/23)
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- Oxidative dimerization of thiols to disulfide using recyclable magnetic nanoparticles
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Abstract: Dimerization of thiol groups to disulfide is an important transformation in chemical processes. In this study, magnetic ion exchanged Montmorillonite-k10 was synthesized and characterized using FTIR, X-ray diffraction and scanning electron microscope techniques. Then, the application of the synthesized catalyst as an efficient oxidizing agent was evaluated in oxidative dimerization of different thiols to corresponding disulfides under optimal reaction conditions. The reaction was easily performed with aromatic, aliphatic and heterocyclic thiols. The magnetic catalyst was easily recovered by applying an external magnet and, further, was reused in successive reactions. Graphical Abstract: [Figure not available: see fulltext.]
- Masnabadi, Nasrin,Ghasemi, Mohammad Hadi,Beyki, Mostafa Hossein,Sadeghinia, Mohammad
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p. 1609 - 1618
(2017/02/15)
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- 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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supporting information
p. 4713 - 4716
(2017/11/21)
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- Regiocontrolled direct C4 and C2-methyl thiolation of indoles under rhodium-catalyzed mild conditions
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A straightforward Rh(iii)-catalyzed general strategy was developed for the site-selective remote C4 (sp2) and C2 (sp3)-methyl thiolation of an indole core, keeping the oxime directing group at the C3 position. The transformation was accomplished under mild conditions with a wide scope and functional group tolerance. The directing group can easily be removed after operation. Methyl substitution at the C2 position of the indole core led to C2 (sp3)-methyl thiolation.
- Maity, Saurabh,Karmakar, Ujjwal,Samanta, Rajarshi
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supporting information
p. 12197 - 12200
(2017/11/16)
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- HETEROARYL COMPOUNDS USEFUL AS INHIBITORS OF SUMO ACTIVATING ENZYME
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Disclosed are chemical entities which are compounds of formula (I); or pharmaceutically acceptable salts thereof; wherein Y, Ra, Ra', Rb, Rc, X1, X2, X3, Rd, Z1, and Z2 have the values described herein and stereochemical configurations depicted at asterisked positions indicate absolute stereochemistry. Chemical entities according to the disclosure can be useful as inhibitors of Sumo Activating Enzyme (SAE). Further provided are pharmaceutical compositions comprising a compound of the disclosure and methods of using the compositions in the treatment of proliferative, inflammatory, cardiovascular, and neurodegenerative diseases or disorders.
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Paragraph 00674
(2016/01/25)
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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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- Synthesis of β-Hydroxysulfides from Thiophenols and Disulfides with tert-Butyl Hydroperoxide as the Oxidant and Reactant
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In this Communication, we developed a new procedure for the synthesis of β-hydroxysulfides from thiophenols or diaryl disulfides with TBHP as the oxidant. In the presence of zinc iodide or potassium iodide, with TBHP as the oxidant and pre-reactant, thiophenols and diaryl disulfides reacted with the methyl group of tBuOH smoothly and selectivity to give the corresponding 2-methyl-1-(arylthio)propan-2-ols as the terminal products in moderate to good yields.
- Feng, Jian-Bo,Wu, Xiao-Feng
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p. 315 - 318
(2016/08/19)
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- Visible light mediated reductions of ethers, amines and sulfides
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Visible light-mediated photoredox catalysis enables the chemoselective reduction of activated carbon–heteroatom bonds as a function of reduction potential. The expansion of the scope of C–X bond reductions towards less activated motifs, such as ethers, amines and sulfides, is important to both organic synthesis and macromolecular degradation method development. In the present report, exploration of photoredox catalysis in alcoholic solvents mediated a decrease in the super-stoichiometric use of iPr2NEt and HCO2H in the reduction of α-keto ethers, amines and sulfides. Additionally, in the absence of fragmentation, [Formula presented] bond formation was afforded, suggesting an intermediate ketyl radicals are present in these transformations.
- Monos, Timothy M.,Magallanes, Gabriel,Sebren, Leanne J.,Stephenson, Corey R.J.
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p. 240 - 248
(2016/07/21)
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- Aryl diazonium salt and thioacetamide: A catalyst free, efficient blend of an inexpensive arylating agent with "s" surrogate for sulphide synthesis
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Novel, facile C-S and S-S bond coupling reactions were achieved by using an aryl diazonium salt as an arylating agent and thioacetamide as a sulphur surrogate. The reaction proceeds smoothly at room temperature without using any transition metal catalyst, ligand or base. Aryl diazonium salts undergo rapid reactions with thioacetamide at room temperature to give the desired products in a much shorter period than the previously reported metal catalysed protocols.
- Bhojane, Jeevan Manohar,Sarode, Sachin Ashok,Nagarkar, Jayashreemilind
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p. 90046 - 90050
(2016/10/07)
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- Haloacid/dimethyl sulfoxide-catalyzed synthesis of symmetrical disulfides by oxidation of thiols
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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
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supporting information
p. 5578 - 5582
(2015/09/21)
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- Cubic Ag2O nanoparticle incorporated mesoporous silica with large bottle-neck like mesopores for the aerobic oxidative synthesis of disulfide
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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
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p. 6323 - 6331
(2015/02/19)
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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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- 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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- α-Arylchalcogenation of acetone with diaryl dichalcogenide via metal-free oxidative C(sp3)-H bond functionalization
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Direct α-arylchalcogenation of acetone with diaryl dichalcogenides has been achieved by using a mixture of TBHP and DTBP oxidants at 120 °C without transition-metal catalyst via oxidative C(sp3)-H bond functionalization. The method exhibits good functional group tolerance and products were isolated in moderate to high yields.
- Yan, Guobing,Borah, Arun Jyoti,Wang, Lianggui,Pan, Zhangjin,Chen, Shuangshuang,Shen, Xuqian,Wu, Xiangmei
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supporting information
p. 4305 - 4307
(2015/06/22)
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- Amino acid and water-driven tunable green protocol to access S-S/C-S bonds via aerobic oxidative coupling and hydrothiolation
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A green methodology utilizing a natural supplement such as l-arginine in conjunction with water and oxygen led to oxidative coupling of thiols into disulfides (S-S bond) whereas thiol-yne coupling to access vinyl sulfides (C-S bond) was facilitated in a nitrogen atmosphere. The tunable protocol offers several advantages such as low catalyst loading, high yields, clean reaction, no over-oxidation of the S-S bond besides being metal/base/waste-free. The synthesis of ubiquitous cystine and glutathione disulfide in the same catalytic system is an added advantage and the catalytic system has been recycled up to seven times. the Partner Organisations 2014.
- Shard, Amit,Kumar, Rajesh,Saima,Sharma, Nidhi,Sinha, Arun K.
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p. 33399 - 33407
(2014/08/18)
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- Efficient silver-catalyzed direct sulfenylation and selenylation of rich arenes
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An efficient protocol for silver/copper-cocatalyzed direct sulfenylation and selenylation of arenes with aryl disulfides and diselenides has been developed. This strategy exhibits excellent functional group tolerance and high regioselectivity. Mono sulfenylation and selenylation products can be exclusively achieved. This reaction provides a simple and practical route to the preparation of aryl sulfides and selenides. This journal is
- Yan, Guobing,Borah, Arun Jyoti,Wang, Lianggui
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supporting information
p. 9557 - 9561
(2015/02/19)
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- (NH 4) 6Mo 7O 34·4H 2O as an efficient, selective, and reusable catalyst for the oxidation of thiols to disulfides using potassium bromate
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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
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supporting information
p. 1236 - 1243
(2013/09/23)
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- Selective oxidation of thiols and alcohols by physically encapsulated nickel schiff-base complex prepared via sol-gel method as nano-catalyst
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A heterogeneous catalyst was prepared by direct physical encapsulation of nickel Schiff-base complex into the silicon dioxide matrix via sol-gel method. The compounds were characterized by FT-IR, SEM, TEM, XRD, CHNS, and AAS. The catalytic performance in the alcohols and thiols oxidation was investigated in the presence of H2O2 (10 mmol, 30%) as oxidant. After five recycle runs, the catalyst showed 13% reduction in activity with slightly Ni(II)-complex leached to the solvent. Varieties of primary and secondary alcohols were efficiently oxidized to the corresponding ketones. Thiols were oxidized in coupling reaction to disulfides in excellent yields using nano-catalyst with H2O2.
- Eshtiagh-Hosseini, Hossein,Tabari, Taymaz,Takjoo, Reza,Eshghi, Hossein
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p. 264 - 272
(2013/04/10)
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- Diverse combinatorial design, synthesis and in vitro evaluation of new HEPT analogues as potential non-nucleoside HIV-1 reverse transcription inhibitors
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New analogues of 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine (HEPT) were synthesized and evaluated for their in vitro activities against HIV-1 in MT-4 cell cultures. Chemical diversity was introduced in 4 of the six positions of the core and the influence of each substituent was studied. This library was built on the basis of a rational diversity analysis with the objective of maximizing diversity and thus, the activity range with a minimum number of synthesized compounds. Among them, 2{1,2,3,1} and 2{1,2,3,4} exhibited the most potent anti-HIV-1 activities (EC50 = 0.015 μg/mL; 0.046 μM, SI >1667) and (EC50 = 0.025 μg/mL; 0.086 μM, SI >1000), respectively, which were about 71-fold and 38-fold more active than the reference compound HEPT (EC50 = 1.01 μg/mL; 3.27 μM, SI >25).
- Puig-De-La-Bellacasa, Raimon,Gimenez, Laura,Pettersson, Sofia,Pascual, Rosalia,Gonzalo, Encarna,Este, Jose A.,Clotet, Bonaventura,Borrell, Jose I.,Teixido, Jordi
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experimental part
p. 159 - 174
(2012/09/05)
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- A facile oxidation of thiols to disulfides catalyzed by CoSalen
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A convenient and facile catalytic oxidation of thiols to the corresponding disulfides is described using CoSalen as the catalyst and air as the oxidizing agent. This new approach provides an efficient method for the preparation of symmetrical disulfides in high yields and under mild conditions. [Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Spectroscopic Identification of Products 3a-3l.] Copyright Taylor and Francis Group, LLC.
- Tan, Cheng-Xia,Pan, Li-Yan,Zhang, Guo-Fu,Li, Yong-Shu
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experimental part
p. 16 - 21
(2012/03/26)
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- First metal- and base-free selective oxidative coupling of thiols in neat ionic liquids: NMR probed "ambiphilic" character of neutral [hmim]Br towards atom-efficient synthesis of disulfides
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The selective oxidative coupling of thiols has been studied in several imidazolium-based ionic liquids in the absence of any base/metal catalysts. Disulfides were obtained from the corresponding thiols in good to excellent yields in 1-hexyl-3-methylimidazolium bromide ([hmim]Br). Furthermore, a 1H NMR-based mechanistic study of the S-S bond formation demonstrated the cooperative role of halide anion and imidazolium cation of [hmim]Br as an "ambiphile" - a character found to be imperative for the efficient syntheses of disulfides. The developed methodology is simple, selective and green that utilises molecular oxygen as an oxidant and produces water as the only by-product. Copyright
- Kumar, Rajesh,Sharma, Nandini,Sharma, Upendra K.,Shard, Amit,Sinha, Arun K.
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supporting information
p. 2107 - 2112,6
(2020/09/02)
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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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- Base-free oxidation of thiols to disulfides using selenium ionic liquid
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We present here the results on the use of 1-n-butyl-3-methylimidazolium methylselenite, [bmim][SeO2(OCH3)], in the synthesis of symmetrical disulfides starting from thiols. This efficient and improved method is general for aromatic, aliphatic, and functionalized thiols affording the disulfides in good to excellent yields after easy work up. The use of a microwave accelerates the reaction and the [bmim][SeO2(OCH 3)] was reused for further oxidation reactions.
- Thurow, Samuel,Pereira, Vanda A.,Martinez, Débora M.,Alves, Diego,Perin, Gelson,Jacob, Raquel G.,Lenard?o, Eder J.
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experimental part
p. 640 - 643
(2011/02/28)
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- Efficient synthesis of unsymmetrical disulfides
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A novel way of synthesizing unsymmetrical disulfides from thiols with DDQ is presented here. This procedure ran in a straightforward manner to give high product yields. Unsymmetrical disulfides were directly synthesized from the corresponding mixture of thiols in equimolar amounts under mild conditions.
- Vandavasi, Jaya Kishore,Hu, Wan-Ping,Chen, Chung-Yu,Wang, Jeh-Jeng
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experimental part
p. 8895 - 8901
(2011/11/30)
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- The first observation of the E,Z configuration of Ar-X-N=S=N-X-Ar (X = S, Se) chains in the crystalline state
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New oligomeric analogues of poly(sulfur nitride), i.e. 3-ClC 6R4-X-N=S=N-X-C6R4Cl-3 (5-8; R = H, F and X = S, Se), were synthesized and structurally characterized in the solid state by single-crystal XRD, in solution by variable-temperature NMR spectroscopy and in the gas phase with DFT/B3LYP calculations. In the crystal, compounds 5-7 display the well-known Z,Z configuration, whereas 8 (R = F, X = Se) is the first compound to display the E,Z configuration amongst twelve structurally defined Ar-X-N=S=N-X-Ar (X = S, Se) derivatives in the hydrocarbon and fluorocarbon series. Through a careful analysis of the packing schemes and the intermolecular interactions of the various compounds, an explanation of the abnormal behaviour of 8 is put forward. The unique E,Z configuration of the title compounds in the crystal is observed for Ar = 3-ClC6F 4 and X = Se - in the presence of eleven Z,Z configurations found by XRD for various Ar and X groups in the hydrocarbon and fluorocarbon series - and explained by specific intermolecular Se???Cl and F???Cl interactions. (Colour code: grey - C, green - Cl, light green - F, blue- N, orange - S, magenta - Se.)
- Makarov, Arkady G.,Bagryanskaya, Irina Yu.,Gatilov, Yuri V.,Kuratieva, Natalia V.,Makarov, Alexander Yu.,Shakirov, Makhmut M.,Alexeyev, Alexey V.,Tersago, Karla,Van Alsenoy, Christian,Blockhuys, Frank,Zibarev, Andrey V.
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p. 4801 - 4810
(2011/03/01)
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- Pyrolysis of α- and β-heteroatoms substituted ethyl phenyl sulfoxides
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A study on the mechanism of the thermal decomposition of α- and β-heteroatoms substituted ethyl phenyl sulfoxides was carried out using 1-chloroethyl phenyl sulfoxide (1); two diastereomeric 1-acetoxyethyl (substituted phenyl) sulfoxides (2a) and (2b); and 2-chloroethyl phenyl, 2-bromoethyl phenyl, and 2-methoxyethyl phenyl sulfoxides (3, 4, 5). The rate of pyrolysis of 1 was 4.8 times faster at 160°C than that of ethyl phenyl sulfoxide used as a reference, while those of 2a and 2b were 107 and 155 times faster, respectively. The results indicate that the lone pair of electrons on the α-heteroatoms has a larger rate acceleration effect than the electronegativity of them. The substituent effects of the phenyl group of 2a and 2b gave positive Hammett ρ-values (ρa= 0.76 and ρb= 0.80 vs. σ). Activation parameters for 2a and 2b are as follows: 2a, ΔH?= 112 kJmol-1, ΔS?= -20 JK-1mol-1; 2b, ΔH?= 107 kJmol-1, ΔS?= -29 JK-1mol-1. Large deuterium kinetic isotope effects for 1-acetoxyethyl-2,2,2-d3 phenyl sulfoxides (2ad and 2bd) were observed (kH/kD= 3.5 ～ 4.1). These results suggest that the pyrolysis of -heteroatom substituted ethyl phenyl sulfoxides proceeds via a five-membered transition state deviated to E1-like in character. On the other hand, from the results of kinetics for the pyrolysis of 3, 4, and 5, no effect by the β-halogen atoms or some deceleration effect by the β-methoxy group was observed. Thus the reaction seems to proceed via an E1-like mechanism. Copyright Taylor & Francis Group.
- Yoshimura, Toshiaki,Sakae, Hironori,Yoshizawa, Masaki,Hasegawa, Kiyoshi,Tsukurimichi, Eiichi
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experimental part
p. 1162 - 1173
(2010/08/06)
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- Silica-supported cobalt(II) tetrasulfophthalocyanine catalyzed aerobic oxidation of thiols to disulfides under neutral conditions
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A very simple and mild reaction is described for the aerobic oxidative coupling of thiols to disulfides by silica-supported cobalt(II) tetrasulfophthalocyanine as the catalyst in non-aqueous media under neutral conditions at room temperature. The catalyst can be reused for the oxidative coupling of several thiols without any significant loss of catalytic activity.
- Shaabani, Ahmad,Safari, Naser,Shoghpour, Samad,Rezayan, Ali Hossein
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experimental part
p. 613 - 615
(2009/07/18)
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- Clean and fast oxidative transformation of thiols to disulfides under solvent-free conditions
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We present here a fast, solvent-free synthesis of symmetrical disulfides using solid supported catalyst (Al2O3/KF). The reaction was performed at room temperature, by gentle heating or under MW irradiation. This efficient and improved method is general for liquid thiols, affording the disulfides in good to excellent yields. The catalytic system can be re-used two times without previous treatment and with comparable activity.
- Lenard?o, Eder J.,Lara, Renata G.,Silva, Márcio S.,Jacob, Raquel G.,Perin, Gelson
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p. 7668 - 7670
(2008/03/30)
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- BIPHENYLOXYACETIC ACID DERIVATIVES FOR THE TREATMENT OF RESPIRATORY DISEASE
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The invention relates to substituted phenoxyacetic acids as useful pharmaceutical compounds for treating respiratory disorders, pharmaceutical compositions containing them, and processes for their preparation.
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Page/Page column 46
(2008/06/13)
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- Indole derivatives for the treatment of depression and anxiety
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The present invention provides compounds of formula (I): which are useful for treating depression, anxiety, and alleviating the symptoms caused by withdrawal or partial withdrawal from the use of tobacco or of nicotine.
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Page/Page column 38
(2010/02/05)
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- Kinetics of the alkaline hydrolysis of 2-thioaryl-3, 5-dinitropyridine derivatives in 50% v/v DMSO-water
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The kinetics of the alkaline hydrolysis of substituted 2-thioaryl-3,5-dinitropyridine have been studied in 50% DMSO-water. The observed rate constants and the second order rate constants were calculated. The thermodynamic parameters for the unsubstituted compound reveals the activating power of the two nitro- and aza-groups.
- Fathalla, Magda F.,Ibrahim, Mahmoud F.,Hamed, Ezzat A.
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p. 150 - 151
(2007/10/03)
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- Macrocycles - Catalysts for autooxidation of thiols
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Me4dibenzo (b, i) 1,4,8,11-tetraaza cyclotetradecatetraene cobalt(II) macrocyclic complex has been used as catalyst for the oxidation of substituted thiophenols viz. 4-methyl, 4-methoxy, 3-amino etc. The catalyst seems to be as effective as its unsubstituted macrocycle. The yield of diphenyldisulphide is 70%. The rate of oxidation of thiols is affected by methyl groups on the macrocyclic ring and it may be due to electronic or steric effect.
- Singh, Randhir,Kumar, Pankaj
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p. 756 - 757
(2007/10/03)
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- Hydrotalcite clay-catalysed air oxidation of thiols
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Hydrotalcite is an efficient catalyst for air oxidation of a variety of aromatic, aliphatic and alicyclic thiols in hexane, affording the corresponding disulfides in excellent to quantitative yields under mild and neutral conditions.
- Hirano, Masao,Monobe, Hiroyuki,Yakabe, Sigetaka,Morimoto, Takashi
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p. 374 - 375
(2007/10/03)
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- Alumina: An Efficient and Reusable Catalyst for the Oxidative Coupling of Thiols with DMSO
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An inexpensive combination of common laboratory reagents, dimethyl sulfoxide (DMSO) and Chromatographic neutral alumina, gives an efficient, selective, and high-yielding oxidation of aromatic, aliphatic and alicyclic thiols to the corresponding disulfides in excellent yields under relatively mild conditions.
- Hirano, Masao,Yakabe, Sigetaka,Monobe, Hiroyuki,Morimoto, Takashi
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p. 472 - 473
(2007/10/03)
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- Simple Oxidation of Thiols with Sodium lodate under Solid-Solution Biphasic Conditions
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A variety of aromatic, aliphatic, and alicyclic thiols were readily oxidised with a combination of sodium iodate and Chromatographic neutral alumina in hexane to afford the corresponding disulfides in excellent yields under mild and neutral conditions.
- Hirano, Masao,Yakabe, Sigetaka,Ando, Ken-Ichiro,Morimoto, Takashi
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p. 816 - 817
(2007/10/03)
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- Oxidation by Chemical Manganese Dioxide. Part 2.1 Simple and High-yielding Synthesis of Symmetrical Disulfides via the Oxidative Coupling of Thiols
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Aromatic, aliphatic, and alicyclic thiols readily underwent oxidative coupling with chemical manganese dioxide in hexane to afford the corresponding disulfides in essentially quantitative yields under relatively mild conditions.
- Hirano, Masao,Yakabe, Sigetaka,Chikamori, Hideki,Clark, James H.,Morimoto, Takashi
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p. 310 - 311
(2007/10/03)
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- Kinetics and mechanism of oxidation of S-phenylthioacetic acids by Ce(IV)
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The kinetics of oxidation of several S-phenylthioacetic acids by ceric ammonium nitrate (CAN) in presence of perchloric acid has been studied spectrophotometrically in 50% (v/v) aqueous acetic acid. The order with respect to Ce(IV) is one and the order with respect to S-phenylthioacetic acid is found to be 0.8. A linear plot of k(obs)-1 vs [substrate]-1 with an intercept on the rate axis suggests the formation of an equilibrium complex between the reactants prior to the rate determining step. The added acrylonitrile retards the reaction rate considerably suggesting that the oxidation process may involve a free radical mechanism. Electron-releasing substituents generally accelerate the rate, while electron-withdrawing groups retard the rate. A good correlation is found to exist between log k1.8 and Hammet σ contants. Rate = k1[Ce(IV)(T)] / 1/K[S] + K(h)[H2O]/K[S][H+] + 1 where 'S' is the substrate K1, K(h) are equilibrium constants and k1 is the rate constant for the rate limiting step.
- Gurumurthy, Rajagopala,Gopalakhrishnan, Mannathusamy,Sathiyanarayanan, Kulathu Iyer
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p. 13731 - 13738
(2007/10/02)
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- A useful sulfur-transfer reaction with tetrathiomolybdate: Conversion of arylamines to aryl disulfides
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A convenient method for the synthesis of a series of symmetrical aryl disulfides from arylamines via the reaction of their stable diazonium salts with tetrathiomolybdate under anhydrous conditions is described.
- Bhar,Chandrasekaran
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p. 785 - 786
(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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- PREPARATION AND SPECTRAL PROPERTIES OF SYMMETRICAL S-ARYL ARENESULFONOTHIOATES (THIOSULFONATES)
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Arenesulfinyl chlorides (4-XC6H4S(O)Cl; X = H, CH3, F, Cl, Br) react with activated zerovalent zinc in benzene at 6 to 8 deg C to give symmetrical S-aryl arenesulfonothioates (thiosulfonates) in good to excellent yields. 2- and 3-substituted arenesulfinyl chlorides (X=Cl, CH3) give a mixture of products (disulfide, thiosulfinate, and/or thiosulfonate). 2,4,6-Triisopropylbenzenesulfinyl chloride reacts with zinc in 1,2-dimethoxyethane to give S-(2,4,6-triisopropylphenyl) 2,4,6-triisopropylbenzenesulfinothioate and bis(2,4,6-triisopropylphenyl) disulfide.Possible mechanisms for the reaction, the 1H and 13C NMR spectra and the chemical ionization and electron impact mass spectra of the thiosulfonates are discussed.The para carbon substituent chemical shifts (Cp-SCS) for the thiosulfonates and for symmetrical diaryl disulfides have been subjected to several dual substituent parameter (DSP) correlations. Key Words: S-aryl-arenesulfonothioates (thiosulfonates); arenesulfinyl chlorides; 1H and 13C NMR; mass spectrometry; substituent shift parameters.
- Freeman, Fillmore,Bartosik, Lisa G.,Bui, Nghe Van,Keindl, Monica C.,Nelson, Eric L.
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p. 375 - 386
(2007/10/02)
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