cas 15718-46-4, DIPYRIMIDIN-2-YL DISULPHIDE

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Multifunctional core-shell Pd@Cu on MoS2 as a visible light-harvesting photocatalyst for synthesis of disulfide by S[sbnd]S coupling
Visible light harvesting materials are considered promising cost-effective heterogenous catalysts for organic synthesis. A novel and efficient synthesis of multifunctional core-shell Pd@Cu/MoS2 nanostructures is utilized for synthesis of disulfides by S[sbnd]S Coupling. The Pd@Cu core-shell was obtained by one-pot hydrothermal synthesis, and a simple method was used to load it onto the MoS2. The as-prepared materials were characterized by scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance spectroscopy, and photoluminescence spectroscopy. The Pd@Cu/MoS2 nanostructures revealed excellent photocatalytic activity, reusability, and stability towards the oxidative coupling of mercaptans to disulfanes. The outstanding photocatalytic activity of Pd@Cu/MoS2 will enhance interest in the field of multifunctional core-shell nanomaterials as photocatalysts for a wide variety of applications.
Yusuf, Mohammad,Song, Sehwan,Park, Sungkyun,Park, Kang Hyun
(2021/02/21)

Method for synthesizing symmetric disulfide compound by taking aryl hydrazine and S8 as raw materials
The invention relates to a method for synthesizing a symmetric disulfide compound by taking aryl hydrazine and S8 as raw materials, and belongs to the technical field of organic synthesis; the methodis characterized in that the aryl hydrazine compound and S8 are used as substrates to react in a reaction solvent under the promotion of alkali to generate the symmetric disulfide organic compound, the reaction gas atmosphere is air or oxygen, the reaction temperature is 40 DEG C-100 DEG C, and the reaction time is 4-24 hours. The synthesis steps are simple, the reaction conditions are mild, S8 which is widely distributed in nature, low in price and easy to obtain is used as a sulfur source, S-S bonds can be constructed only under the promotion of alkali without transition metal catalysis, theyield is as high as 95%, the applicable reaction substrate range is wide, the operation is simple and feasible, the synthesis cost is low, the environmental pollution is small, and a new thought is provided for the synthesis of the symmetric disulfide organic compound.
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Paragraph 0064

(2020/11/23)

Biocatalytic synthesis of diaryl disulphides and their bio-evaluation as potent inhibitors of drug-resistant Staphylococcus aureus
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
p. 171 - 178
(2019/01/04)

Natural gallic acid catalyzed aerobic oxidative coupling with the assistance of MnCO3 for synthesis of disulfanes in water
The formation of S-S bonds has great significance and value in synthetic chemistry and bioscience. To pursue a sustainable approach for such a synthesis, an aerobic oxidative coupling method for the efficient preparation of organic disulfanes, using a low-toxic natural gallic acid as an organocatalyst, inexpensive MnCO3 as a cocatalyst, O2 as the terminal oxidant and water as the solvent, has been successfully developed. Such metal-organic cooperative catalytic protocol provided an access to various symmetrical and unsymmetrical disulfanes in up to 99% yield. Gram scale synthesis with practical convenience and low loading of catalysts further illustrates the practicability of our method.
Song, Lijuan,Li, Wenhao,Duan, Wenxue,An, Jichao,Tang, Shanyu,Li, Longjia,Yang, Guanyu
supporting information
p. 1432 - 1438
(2019/03/26)

Three monomeric compounds containing the dipyrimidine-2-thiolategold(I) anion
Three complexes containing the dipyrimidine-2-thiolategold(I) anion, [Au(2-pymS)2]-, (2-pymSH = pyrimidine-2-thione), Na[Au(2-pymS)2] (1), N(C2H5)4[Au(2-pymS)2] (2), and H[Au(2-pymS)2] (3), have been synthesized and characterized by spectroscopy (1H NMR, IR, and ESI –MS) and by X-ray crystallography. The monomeric compounds are easily solubilized in water and in various polar organic solvents. The complex anion shows a linear S–Au–S geometry in all three compounds, but the counter cations create a different space group for each compound and also deter Au–Au interactions.
Neils, Thomas L.,Biros, Shannon M.,Staples, Richard J.,Wackerle, Brandon G.,Harrison, Robert B.
p. 474 - 478
(2018/11/06)

Dialkyl Dicyanofumarates as Oxidizing Reagents for the Conversion of Thiols into Disulfides and Selenols into Diselenides
Aliphatic and aromatic thiols react smoothly with dialkyl dicyanofumarates in CH2Cl2 at room temperature to give the corresponding disulfides in excellent yields. Aliphatic 1,2-, 1,3-, and 1,4-dithiols afford cyclic disulfides. Analogous reaction courses were observed for selenols, and the required diselenides also formed in nearly quantitative yields. In all of the reactions, dialkyl dicyanosuccinates formed as 1:1 mixtures of diastereoisomers as the only other product. Cysteamine (2-mercaptoethylamine) behaved differently; the Michael addition of the primary amine group led to the complete consumption of the dicyanofumarate, and the formation of the disulfide containing an enamine moiety occurred without the formation of dicyanosuccinate.
Mlostoń, Grzegorz,Capperucci, Antonella,Tanini, Damiano,Hamera-Fa?dyga, Ró?a,Heimgartner, Heinz
p. 6831 - 6839
(2017/09/11)

An environmentally benign and selective electrochemical oxidation of sulfides and thiols in a continuous-flow microreactor
A practical and environmentally benign electrochemical oxidation of thioethers and thiols in a commercially-available continuous-flow microreactor is presented. Water is used as the source of oxygen to enable the oxidation process. The oxidation reaction utilizes the same reagents in all scenarios and the selectivity is solely governed by the applied potential. The procedure exhibits a broad scope and good functional group compatibility providing access to various sulfoxides (15 examples), sulfones (15 examples) and disulfides (6 examples). The use of continuous flow allows the optimal reaction parameters (e.g. residence time, applied voltage) to be rapidly assessed, to avoid mass- and heat-transfer limitations and to scale the electrochemistry.
Laudadio, Gabriele,Straathof, Natan J. W.,Lanting, Menno D.,Knoops, Benny,Hessel, Volker,No?l, Timothy
supporting information
p. 4061 - 4066
(2017/09/07)

COMPOUNDS THAT INHIBIT MCL-1 PROTEIN
Provided herein are myeloid cell leukemia 1 protein (Mcl-1) inhibitors, methods of their preparation, related pharmaceutical compositions, and methods of using the same. For example, provided herein are compounds of Formula I, and pharmaceutically acceptable salts thereof and pharmaceutical compositions containing the compounds. The compounds and compositions provided herein may be used, for example, in the treatment of diseases or conditions, such as cancer.
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Page/Page column 1865; 1866

(2017/09/15)

3,6-Di(pyridin-2-yl)-1,2,4,5-tetrazine (pytz) mediated metal-free mild oxidation of thiols to disulfides in aqueous medium
Thiols are efficiently oxidized to disulfides (RSSR) in the presence of 3,6-di(pyridin-2-yl)-1,2,4,5-tetrazine (pytz) in aqueous medium, as well as in the absence of a solvent under mild and metal-free conditions. A broad range of alkyl, aryl and heterocyclic symmetrical disulfides can be easily obtained in almost quantitative yields. The X-ray single crystal structure of 2-aminocyclopent-1-ene-1-carbothioic dithioperoxyanhydride (disulfide obtained from 2-aminocyclopentene-1-dithiocarboxylic acid, ACDA) is reported. The reaction mechanism has been studied thoroughly. It is shown that the reaction proceeds through the formation of an organosulphur radical. Pytz interacts with thiol to accept one electron and produces an organosulphur radical. Pytz ultimately accepts two electrons to form H2pytz and is capable of oxidizing 2 equivalents of thiols.
Samanta, Suvendu,Ray, Shounak,Ghosh, Abhisek Brata,Biswas, Papu
p. 39356 - 39363
(2016/06/01)

Organocatalytic visible light induced S-S bond formation for oxidative coupling of thiols to disulfides
In this work, we developed a visible light induced oxidative coupling of thiols into the corresponding disulfides in a process catalyzed by an inexpensive and non hazardous Rose Bengal dye. Our optimization study revealed that the use of Rose Bengal catal
Tankam, Theeranon,Poochampa, Kamolrut,Vilaivan, Tirayut,Sukwattanasinitt, Mongkol,Wacharasindhu, Sumrit
p. 788 - 793
(2016/01/20)

Enzymatic thiol Michael addition using laccases: Multiple C-S bond formation between p-hydroquinones and aromatic thiols
Laccases create C-C, C-O or C-N bonds and have been investigated intensively as catalysts for green chemistry and white biotechnology. However, little is known about C-S bond formation in laccase-catalyzed reactions. We have used the laccases from Pycnopo
Schlippert, Max,Mikolasch, Annett,Hahn, Veronika,Schauer, Frieder
supporting information
p. 106 - 114
(2016/02/27)

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
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.
p. 113 - 123
(2015/04/14)

Hypervalent iodine(III)-promoted metal-free S-H activation: An approach for the construction of S-S, S-N, and S-C bonds
The activation of the sulfur atom of thiols with (diacetoxyiodo)benzene (DIB) has been explored in the preparation of symmetrical disulfides and sulfenamides. Disulfides can be produced in excellent yields (75-95%) upon treatment of thiols with DIB. The reaction was complete in less than five minutes at room temperature. Aliphatic, aromatic, and heteroaromatic thiols are compatible with this transformation. Moreover, heteroaromatic disulfides obtained from heteroaromatic thiols further reacted with a nucleophilic amine in the presence of a base to provide the corresponding sulfenamides in fair to good yields (43-90%) in a one-pot fashion. The methodology was successfully extended to indole as a representative electron-rich aromatic compound, which allowed successful construction of a S-C bond in one pot. The key benefits of this reaction include lower toxicity, low cost of DIB reagent, and mild reaction conditions (room temperature, undried solvents and open flask).
Rattanangkool, Eakkaphon,Krailat, Watanya,Vilaivan, Tirayut,Phuwapraisirisan, Preecha,Sukwattanasinitt, Mongkol,Wacharasindhu, Sumrit
p. 4795 - 4804
(2014/08/05)

Amino acid and water-driven tunable green protocol to access S-S/C-S bonds via aerobic oxidative coupling and hydrothiolation
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.
p. 33399 - 33407
(2014/08/18)

Modification of thionucleobases in ionic liquids
A simple method was established for the preparation of thio-substituted thionucleobases using room temperature ionic liquids (RTILs) such as 1-butyl-3-methylimidazolium trifluoroacetate [BMIM]+[CF3COO]- and 1-methoxyethyl-3-methylimidazolium trifluoroacetate [MeOEtMIM]+[CF3COO]- as solvents and catalysts without any other catalyst. These reactions proceeded efficiently in RTILs with excellent yield of products. RTILs can be recycled and reused effectively without further purification.
Hu, Xiaomei,Zhang, Bixian,Dong, Shijia,Gao, Yunfei
(2015/02/19)

One-pot palladium-catalyzed borrowing hydrogen synthesis of thioethers
Palladium on magnesium oxide is able to allow a one-pot reaction to synthesize thioethers from thiols and aldehydes formed in situ from the respective alcohol by means of a borrowing hydrogen method. The reaction is initiated by dehydrogenation of the alcohol to give a palladium hydride intermediate and an aldehyde. The latter reacts with a thiol involving most probably the intermediacy of a thionium ion RCHi￡S+R, which can be reduced in situ by the metal hydride to afford thioethers. Lending support: Palladium nanoparticles on MgO catalyze the synthesis of thioethers from thiols and aldehydes formed in situ from alcohols by means of the borrowing hydrogen method (see scheme). Dehydrogenation of the alcohol gives a palladium hydride intermediate and an aldehyde. The latter reacts with a thiol through a thionium ion, which is reduced by the metal hydride to afford thioethers.
Corma, Avelino,Navas, Javier,Rodenas, Tania,Sabater, Maria J.
p. 17464 - 17471
(2014/01/06)

Supported iron oxide nanoparticles: Recoverable and efficient catalyst for oxidative S-S coupling of thiols to disulfides
Supported iron oxide nanoparticles are found to be efficient and recoverable catalyst in the selective oxidation of thiols to their corresponding disulfides using hydrogen peroxide as green oxidant at room temperature. The protocol features an easy work-up, simplicity and the utilizing mild reaction conditions, as well as high selectivity toward disulfides, are highly advantageous compared to alternative reported methodologies. The supported iron oxide nanoparticles could be easily recovered and reused several times without any loss of activity. ICP-MS results prove that there is no metal leaching observed, and demonstrating the stability of the catalyst under the reaction conditions.
Rajabi, Fatemeh,Kakeshpour, Tayeb,Saidi, Mohammad Reza
p. 13 - 17
(2013/07/26)

(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)

Synthesis of disulfides by laccase-catalyzed oxidative coupling of heterocyclic thiols
A new method employing a laccase-mediator system as the catalyst and aerial oxygen as the oxidant has been developed for the oxidative coupling of heterocyclic thiols to the corresponding disulfides with yields up to 95% under mild reaction conditions.
Abdel-Mohsen, Heba T.,Sudheendran, Kavitha,Conrad, Juergen,Beifuss, Uwe
supporting information
p. 1490 - 1495
(2013/09/24)

Reactivity of di-iodine toward thiol: Desulfuration reaction of 5-nitro-2-mercapto-benzimidazole upon reaction with di-iodine
The reaction of 2-mercapto-benzoic acid (H2MBA), 2-mercato-nicotinic acid (H2MNA), and 2-mercapto-pyrimidine (PMTH) with a twofold molar amount of di-iodine (I2) results in the isolation of crystals of the neutral disulfid
Corban,Antoniadis,Hadjikakou,Kourkoumelis,Tyurin,Dolgano,Milaeva,Kubicki,Bernhardt,Tiekink,Skoulika,Hadjiliadis
p. 498 - 511
(2012/11/07)

Silica-supported ICl as a novel heterogeneous system for the rapid and selective oxidation of thiols to symmetrical disulfides
ICl-SiO2 as a new reactive system was prepared by treatment of iodine monochloride with activated silica gel in chloroform. ICl-SiO2 in a heterogeneous system efficiently converted thiols to the corresponding disulfides under mild conditions in high yields at room temperature.[image omitted].
Karami, Bahador,Farahi, Mahnaz,Montazerozohori, Morteza,Nasr-Esfahani, Masoud
experimental part
p. 483 - 488
(2012/06/16)

Melamine hydrogen peroxide (MHP): Novel and efficient reagent for the chemo- and homoselective and transition metal-free oxidation of thiols and sulfides
Melamine hydrogen peroxide (MHP) as a novel hydrogen peroxide adduct was easily prepared. Both chemo- and homoselective oxidation of thiols and sulfides to their corresponding disulfides and sulfoxides occurred by using MHP in moderate to excellent yields. AlCl3 acts as a suitable activator in the oxidation of sulfides with MHP.
Chehardoli, Gholamabbas,Zolfigol, Mohammad Ali
experimental part
p. 193 - 203
(2010/05/02)

Aerobic oxidation of some arylthiols catalyzed by a new manganese (III) schiff-base complex
Bis(2-hydroxybenzene)phthaldiimine (BHBPDI) as a new quadridentate Schiff base ligand and its [Mn(III)(BHBPDI)Cl] complex were synthesized and characterized by analytical and spectral data (MS, FT-IR, UV-Vis, 1H NMR). The aerobic oxidation of thiols catalyzed by Mn(III)-complex using molecular oxygen was studied at room temperature. The reaction proceeded to yield the corresponding symmetric disulfides in good to high yields. The reaction was retarded when the reaction mixture was saturated with nitrogen gas. This system provides an efficient and convenient method for the oxidation of thiols to symmetric disulfides.
Montazerozohori, Morteza,Fradombe, Leila Zamani
experimental part
p. 509 - 515
(2010/06/17)

Aerobic oxidation of thiols to disulfides using iron metal-organic frameworks as solid redox catalysts
Aerobic oxidation of thiols to disulfides has been carried out using iron metal-organic frameworks (MOFs) as solid redox catalysts with very high yield and selectivity in acetonitrile under mild reaction conditions.
Dhakshinamoorthy, Amarajothi,Alvaro, Mercedes,Garcia, Hermenegildo
supporting information; experimental part
p. 6476 - 6478
(2010/10/21)

Efficient and convenient oxidation of thiols to symmetrical disulfide with silica-PCl5/NaNO2 in water
A very simple, environmentally benign, cost-effective, and efficient synthesis of disulfides from thiols using silica-PCl5/NaNO2 in aqueous medium has been described. The reaction was found to occur rapidly under mild conditions, and disulfides were obtained easily through a simple workup.
Pathak, Uma,Pandey, Lokesh Kumar,Mathur, Sweta
experimental part
p. 2923 - 2927
(2009/12/03)

Fast and highly efficient solid state oxidation of thiols
A fast and efficient solid state method for the chemoselective room temperature oxidative coupling of thiols to afford their corresponding disulfides using inexpensive and readily available moist sodium periodate as the reagent is described. The reaction was applicable to a variety of thiols giving high yields after short reaction times. Comparison of yield/time ratios of this method with some of those reported in the literature shows the superiority of this reagent over others under these conditions.
Montazerozohori, Morteza,Joohari, Shiva,Karami, Bahador,Haghighat, Nasrin
p. 694 - 702
(2008/02/01)

{[K.18-Crown-6]Br3}n: a unique tribromide-type and columnar nanotube-like structure for the oxidative coupling of thiols and bromination of some aromatic compounds
Reaction of 18-crown-6 with KBr and then with bromine (Br2) afforded a unique tribromide salt with a nanotube-like structure ({[K.18-crown-6]Br3}n). Oxidative coupling of thiols and bromination of some aromatic compounds is the first report on the chemistry of this reagent.
Zolfigol, Mohammad Ali,Chehardoli, Gholamabbas,Salehzadeh, Sadegh,Adams, Harry,Ward, Michael D.
p. 7969 - 7973
(2008/03/14)

Tungstate sulfuric acid: A novel and efficient solid acidic reagent for the oxidation of thiols to disulfides and the oxidative demasking of 1,3-dithianes
Tungstate sulfuric acid in combination with various oxidants was found to be an efficient reagent for the conversion of thiols to disulfides at r.t. in good to excellent yields. The selective oxidative deprotection of 1,3-dithianes to their parent carbonyl compounds at r.t. was also observed with this reagent. Copyright Taylor & Francis Group, LLC.
Karami, Bahador,Montazerozohori, Morteza,Habibi, Mohammad Hossein
p. 2825 - 2831
(2007/10/03)

Bis (salicylaldehyde-1,2-phenylene diimine)Mn(III) chloride (Mn(III)-salophen) catalysed oxidation of thiols to symmetrical disulfides using urea hydrogen peroxide (UHP) as mild and efficient oxidant
A variety of thiols were oxidised efficiently by a catalytic amount of Mn(III)-salophen 1 in the presence of urea hydrogen peroxide adduct 2 as a convenient and mild oxidant to afford the corresponding disulfides in high yields in quite short reaction tim
Karami, Bahador,Montazerozohori, Morteza,Habibi, Mohammad Hossein
p. 490 - 492
(2007/10/03)

General method of obtaining deuterium-labeled heterocyclic compounds using neutral D2O with heterogeneous Pd/C
A protocol of a versatile H-D exchange reaction of heterocyclic compounds catalyzed by heterogeneous Pd/C in D2O is described. The reaction of various nitrogen-containing heterocycles with 10% Pd/C (10 wt % of the substrate) under hydrogen atmosphere in D2O as a deuterium source at 110-180 °C for 24 h afforded the corresponding deuterated compounds with satisfactory efficiency of deuteration in moderate to excellent isolated yields. Furthermore, the Pd/C-H2-D2O system can be extended to the direct deuteration of biologically active compounds such as sulfamethazine, which is used as a synthetic antibacterial drug for fat stocks and would be applied as a general method for the preparation of the standard materials for the analysis of residual chemicals in foods and so on.
Esaki, Hiroyoshi,Ito, Nobuhiro,Sakai, Shino,Maegawa, Tomohiro,Monguchi, Yasunari,Sajiki, Hironao
p. 10954 - 10961
(2007/10/03)

Urea- Hydrogen Peroxide (UHP) oxidation of thiols to the corresponding disulfides promoted by maleic anhydride as mediator
Urea-hydrogen peroxide (UHP) was used in the presence of maleic anhydride as mediator in a simple and convenient method for the oxidation in high yield of some thiols to the corresponding disulfides. Peroxymaleic acid formed in situ from the reaction of U
Karami, Bahador,Montazerozohori,Habibi
p. 1358 - 1363
(2007/10/03)

Selective and convenient oxidation of thiols to disulfides using n-butyltriphenylphosphonium dichromate (Bun PPh3) 2Cr2O7 in solution, under solvent-free conditions and microwave irradiation
A variety of aliphatic, aromatic, and heteroaromatic thiols were rapidly and cleanly converted to their corresponding disulfides in excellent yields using n-butyltriphenylphosphonium dichromate (BTPPDC) in acetonitrile solution under solvent-free conditions and microwave irradiation. Selective oxidation of thiols in the presence of other oxidizable functional groups, such as alcohol and sulfide, is a noteworthy advantage of this method.
Mohammadpoor-Baltork, Iraj,Memarian, Hamid Reza,Bahrami, Kiumars
p. 2315 - 2321
(2007/10/03)

A very simple method for the preparation of symmetrical disulfides
Addition of sulfuryl chloride to an alkyl- or arylthiol in a 1:2 ratio under solvent free conditions or in CH2Cl2 solution produces the corresponding disulfides in nearly quantitative yields. A serendipitiously discovered, extremely simple, fast and previously unreported method for the preparation of symmetrical aliphatic, aromatic and heteroaromatic disulfides is reported. Addition of sulfuryl chloride to an alkyl- or arylthiol in a 1:2 ratio under solvent free conditions or in dichloromethane solution produces the corresponding disulfides in nearly quantitative yields with the concomitant elimination of gaseous SO2 and 2 equiv of HCl. Thus, optimally the reaction needs no work-up at all leaving the disulfide as the sole product in excellent yield. In dichloromethane solution, the reaction is conveniently carried out in a rotary evaporator by mixing the solvent, thiol and SO2Cl2 in a round-bottomed flask followed by evaporation of the volatiles.
Leino, Reko,L?nnqvist, Jan-Erik
p. 8489 - 8491
(2007/10/03)

Oxidative coupling of thiols to disulfides with iodine in wet acetonitrile
Different types of thiols were oxidatively coupled to their disulfides with iodine in wet acetonitrile at room temperature and in excellent yields.
Zeynizadeh, Behzad
p. 564 - 566
(2007/10/03)

Tetrabutylammonium peroxydisulfate in organic synthesis. XII. A convenient and practical procedure for the selective oxidation of thiols to disulfides with tetrabutylammonium peroxydisulfate under solvent-free conditions
An efficient method for the oxidative coupling of thiols to their corresponding disulfide by (n-Bu4N2)S2O8 in high yields under solvent-free conditions is described. The reaction was applicable to a variety of thiols with high chemoselectivity.
Chen, Fen-Er,Lu, Yun-Wen,He, Yan-Ping,Luo, You-Fu,Yan, Ming-Guo
p. 3487 - 3492
(2007/10/03)

Heterocycle-substituted stable thioaminyl radicals: Isolation, ESR spectra, and magnetic properties
N-[(2-Benzothiazolyl)thio]- (1), N-[(2-benzoxazolyl)thio]- (2), and N-(2-pyrimidylthio)-2,4,6-trisubstituted-phenylaminyls (3) were generated by oxidation of the corresponding amines. Although 2 and were not sufficiently persistent to be isolated, I was very persistent and could be isolated as radical crystals. The ESR spectra of nondeuterated and partially deuterated 1-3 radicals were measured, and the spin density distributions were estimated from the hyperfine coupling constants. Ab initio molecular orbital calculations were made for 1 to discuss the spin density distribution in more detail. Single-crystal X-ray crystallographic analysis was performed for one radical. Magnetic properties were measured for isolated four radicals with a SQUID. Two radicals showed ferromagnetic interaction, and analyses of (x)T vs T plots with the one-dimensional regular Heisenberg model gave 2J/k(B) =5.8 and8.6K. The remaining two radicals showed antiferromagnetic interaction. Analyses of the (x)T vs T plots with the Curie-Weiss law or dimer model gave Θ = -1.4 K and 2J/k(B) = -1370K. The strong antiferromagnetic interaction could be explained in terms of the X-ray crystallographic results.
Miura,Tomimura,Teki
p. 7889 - 7895
(2007/10/03)

Oxidation in fluoro alcohols: Mild and efficient preparation of disulfides from thiols
Quantitative oxidative conversion of thiols to disulfides was effected by aqueous 30% H2O2 in trifluoroethanol at ambient temperature under neutral conditions.
Kesavan, Venkitasamy,Bonnet-Delpon, Daniele,Begue, Jean-Pierre
p. 223 - 225
(2007/10/03)

Solid state oxidation of thiols to disulfides using ammonium persulfate
A solid state method for the oxidation of thiols is described that uses benign oxidant, ammonium persulfate.
Varma, Rajender S.,Meshram, Harshadas M.,Dahiya, Rajender
p. 1249 - 1255
(2007/10/03)

Preparation of a stable diaryl trisulfide from a sacrificial sulfur cathode and 2-chloropyrimidine
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Genesty, Marc,Pommatau, Gilles,Degrand, Chantal
p. 952 - 954
(2007/10/03)

Bis(1-benzyl-4-aza-1-azoniabicyclo[2.2.2]octane) peroxodisulfate: A mild and efficient oxidant for oxidation of thiols, sulfides and aromatic amines to the corresponding disulfides, sulfoxides and azo compounds
Bis(1-benzyl-4-aza-1-azoniabicyclo[2.2.2]octane) peroxodisulfate (BAABCPS) 1, readily prepared as orange solid from commercially available 1,4-diazabicyclo[2.2.2]octane (DABCO) and potassium peroxodisulfate converts thiols, sulfoxides and aromatic amines to the corresponding disulfides, sulfoxides and azo compounds respectively.
Hajipour,Mohammadpoor Baltork,Kianfar
p. 607 - 610
(2007/10/03)

Selective and simple phase transfer catalyzed synthesis of disulfides from thiols
Two novel methods of synthesis of disulfides from thiols or their Na salts in the phase transfer catalytic system CBr4/18-crown-6/benzene or toluene are developed and the products isolated in 67-8.8% yields.
Abele, Edgars,Abele, Ramona,Lukevics, Edmunds
p. 624 - 625
(2007/10/03)

Benzyltriphenylphosphonium Peroxodisulfate (PhCH2PPh3)2S2O8: A Mild and Inexpensive Reagent for Efficient Oxidation of Organic Compounds under Nonaqueous and Aprotic Conditions
Benzyltriphenylphosphonium peroxodisulfate is an easily prepared and stable reagent. It could be used as an oxidant under aprotic and nonaqueous conditions in organic solvents. This reagent oxidizes different classes of alcohols to carbonyl compounds, thiols to disulfides, sulfides to sulfoxides, oximes to carbonyl compounds and aromatic amines to azo compounds efficiently. α-Hydroxy carboxylic acids and phenylacetic acids undergo oxidative decarboxylation to produce carbonyl compounds.
Mohammadpoor-Baltork, Iraj,Hajipour, Abdol Reza,Mohammadi, Hasan
p. 1649 - 1653
(2007/10/03)

n-Butyltriphenylphosphonium dichromate: an efficient and selective oxidizing agent
The preparation of n-butyltriphenylphosphonium dichromate is described. This reagent oxidizes alcohols to carbonyl compounds, thiols to disulfides and aromatic amines to azo compounds efficiently. Benzylic and allylic oximes are selectively oxidized to their corresponding carbonyl compounds in the presence of aluminium chloride.
Baltork, I. Mohammadpoor,Sadeghi, M. M.,Mahmoodi, N.,Kharamesh, B.
p. 438 - 441
(2007/10/03)

Thione-Disulfide Interchange of some Heterocyclic Tautomeric Thiones and their Symmetrical Bisulfides
The UV/Vis spectroscopic properties of some symmetrical disulfides derived from potentially tautomeric thiones are investigated. Reversed thione-disulfide transformation is observed, and the influence of several factors including the nature of solvent, concentration, and UV irradiation, is studied. Possible implication of the tautomeric thiol form and the importance of this thione-disulfide redox system in biological aspects is suggested. A general scheme including monomer-dimer equilibrium, thione-thiol tautomeric equilibrium, and reversible thiol-disulfide redox behaviour is proposed in order to explain the factors affecting the overall thione-disulfide transformation.
Stoyanov,Stoyanova,Antonov,Karagiannidis,Akrivos
p. 495 - 504
(2007/10/03)

Spectroscopic and computational investigation of the ground and low excited states of some symmetrical heterocyclic disulfides
The electronic absorption and emission spectra of some symmetrical heterocyclic disulfides are investigated. The reversible disulfide - thione transformation in water is discussed in view of the complex equilibrium processes present. UV irradiation and pH influence on the above transformation is also studied. The emission properties at room and low temperature are related to the computed molecular geometries of the ground and low excited states of the compounds.
Stoyanov, Stefan,Stoyanova, Tatyana,Akrivos, Pericles D.,Karagiannidis, Petros,Nikolov, Peter
p. 927 - 931
(2007/10/03)

Efficient Oxidation of organic Compounds with Sodium and Silver Bromates NaBrO3, AgBrO3, in Non-Aqueous Solvents in the Presence of Lewis Acids
The syntehtic utility of sodium and silver bromates in the presence of Lewis acids as catalysts in organic solvents is described.They are efficient for the oxidation of alcohols, acyloins, and hydroquinones to their corresponding carbonyl compounds.The oxidation coupling of thiols performs well in the absence of the catalysts.Silver bromate is able to transform primary benzylic and saturated alcohols, aldehydes, and primary benzylic carbon-hydrogen bonds to their carboxylic acids efficiently.Secondary benzylic carbon-hydrogen bonds are oxidized to their carbonyl compounds with sodium and silver bromates.
Firouzabadi, Habib,Mohammadpoor-Baltork, Iraj
p. 2319 - 2326
(2007/10/03)

Disulfides. 1. Syntheses Using 2,2'-Dithiobis(benzothiazole)
2,2'-Dithiobis(benzothiazole) produces unsymmetric disulfides containing the 2-benzothiazolyl fragment in both high yield and purity when reacted with 1 equiv of a variety of alkane and arene thiols under mild conditions.In turn, these unsymmetric disulfides react with a variety of thiols to produce either symmetric disulfides or new unsymmetric disulfides in excellent yields.At room temperature, 2 equiv of most thiols are oxidized essentially quantitatively to the corresponding symmetric disulfide by 2,2'-dithiobis(benzothiazole).Thiols employed at various stages include 1-propanethiol, 2-propanethiol, 2-methyl-2-propanethiol, phenylmethanethiol, 2-mercaptoethanol, 2-mercaptoethylamine (MEA) hydrochloride, 2-methoxybenzenethiol, 4-methoxybenzenethiol, 4-aminobenzenethiol, 4-acetamidobenzenethiol, 4-bromobenzenethiol, 4-methylbenzenethiol, N-acetyl-L-cysteine, and sodium 2-mercaptoethanesulfonate (MESNA).Various disulfides were inactive in vivo against cyanide poisoning.
Brzezinska, Ewa,Ternay, Andrew L.
p. 8239 - 8244
(2007/10/02)

Ozonation of substituted 2-thiouracils and pyrimidine-2-thione
The ozonation of substituted 2-thiouracils and pyrimidine-2-thione is reported; this provides a new method for the synthesis of several pyrimidine derivatives.
Crestini, Claudia,Saladino, Raffaele,Nicoletti, Rosario
p. 1631 - 1634
(2007/10/02)

Zinc Bismuthate Zn(BiO3)2. I. A Useful Oxidizing Agent for the Efficient Oxidation of Organic Compounds
Zinc bismuthate is an easily prepared and a stable compound.It could be used as an oxidant in organic solvents under aprotic or in the presence of a catalytic amount of a protic solvent.Primary and secondary saturated, allylic, and benzylic alcohols are converted to their carbonyl compounds in high yields.Mildness of the reagent is shown by the oxidation of thiols to their disulfides in excellent yields.Thioethers are also oxidized to their corresponding sulfoxides in good yields.
Firouzabadi, Habib,Mohammadpour-Baltork, Iraj
p. 1131 - 1134
(2007/10/02)

Thione-thiol tautomerism and stability of 2- and 4-mercaptopyridines and 2-mercaptopyrimidines
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Stoyanov,Petkov,Antonov,Stoyanova,Karagiannidis,Aslanidis
p. 1482 - 1489
(2007/10/02)