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All total 162 Articles be found
All total 162 Articles be foundOxidation of thiols using K2S2O8 in ionic liquid
Hajipour, Abdol R.,Mostafavi, Majid,Ruoho, Arnold E.
, p. 1920 - 1923 (2009)
A green, straightforward, and novel method for oxidation of thiols to the corresponding disulfides is reported using K2S2O8 in the ionic liquid 1-butyl-3-methylimidazolium bromide [(bmim)Br] at 65-70C. The corresponding disulfides were obtained in excellent yield and short reaction time.
Selective synthesis of organic sulfides or disulfides by solvent exchange from aryl halides and KSCN catalyzed by NiCl2·6H2O
Abbasi, Mohammad,Nowrouzi, Najmeh,Latifi, Hadis
, p. 112 - 117 (2016)
A method for selective synthesis of symmetric sulfides or disulfides from the reaction of aryl halides with KSCN by solvent exchange is introduced. Aryl halides were selectively converted to the symmetric disulfides or sulfides in high yields when they are treated with KSCN in the presence of NiCl2·6H2O and DMAP at 140?°C in DMF or poly ethylene glycol (PEG-200) respectively.
On the reaction of triaryl trithioarsenites, (ArS)3As, with iodine
Markaki, Maria D.,Ioannou, Panayiotis V.
, p. 921 - 929 (2006)
Iodine in dry nonprotic solvents oxidizes triaryl trithioarsenites, (ArS)3 As, to As(III) iodide, AsI3, and disulfides, ArSSAr. The reaction most likely involves arylsulfenyl iodide, ArSI, as an intermediate. With triphenyl and tris(
Synthesis of disulfides by the oxidative coupling of thiols with calcium hypochlorite and silica gel in hexane
Hirano, Masao,Yakabe, Shigetaka,Uraoka, Nobuteru,Morimoto, Takashi
, p. 360 - 363 (1998)
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A facile, high-yielding method for the conversion of halides to mercaptans
Bieniarz,Cornwell
, p. 939 - 942 (1993)
An efficient, high-yield, one-pot preparation of alkyl and activated aryl mercaptans is presented. The method relies on sodium thiophosphate displacement of the halide, followed by mild hydrolysis of the intermediate phosphorothioate.
Synthesis and 13C NMR spectra of N-substituted para-quinone imines: II. N-arylthio- and N-arylsulfonyl-l,4-benzoquinone imines with enhanced electron-withdrawing character of the quinoid ring
Pirozhenko,Avdeenko,Yusina,Konovalova
, p. 1142 - 1148 (2002)
Introduction of chlorine substituents into quinone imine fragment results in virtually the same variations in the chemical shifts of the quinoid ring carbons both in N-arylthio and N-arylsulfonyl-1,4-benzoquinone imines as compared to the unsubstituted analogs. In both classes of chloro-substituted compounds the effect of substituents in the benzene ring on the character and the range of chemical shifts variations for the carbon signals from the quinoid ring also turned out to be identical. Any differences observed may be due to the change in the geometry of the molecules, in particular, to the increase in the bond angle C=N-S.
An environmentally friendly oxidation of thiols to disulfides by calcium hypochlorite and montmorillonite K10 in hexane
Hirano, Masao,Yakabe, Shigetaka,Fukami, Masataka,Morimoto, Takashi
, p. 2783 - 2788 (1997)
Aromatic, aliphatic, and alicyclic thiols can be readily oxidized to the disulfides quantitatively by calcium hypochlorite and moist Montmorillonite K10 under mild and neutral conditions.
Reactions of arensulfenamides with olefins in the presence of picric acid
Zyk,Beloglazkina,Mamaeva
, p. 1617 - 1619 (1998)
N-(2-and 4-Nitrophenylthio)morpholines in the presence of equimolar amounts of picric acid enter into the reaction of electrophilic sulfenylation of the C=C norbornene bond to give bi-and tricyclic sulfides. With cyclohexene, trans-2-arylthiocyclohexanol are formed.
Pyridine N-Sulphides. Some Simple N-Arylthiopyridinium Salts and a Possible Source of Arylsulphenium Ions
Abramovitch, Rudolph A.,Miller, Adrian L.,Pilski, Jacek
, p. 703 - 704 (1981)
N,N'-Dipyridinium disulphide dichloride (1) and 1-(4-nitrophenylthio)pyridinium chloride (5) and its 4-NMe2 derivative (2) have been synthesized and their structures established unambiguously; they undergo nucleophilic attack at sulphur rather than in the
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Saville
, p. 1730,1733 (1960)
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METHOD FOR THE SYNTHESIS OF 1,4-BIS(4'-AMINOPHENYLTHIO)BENZENE
Yuferov, A. M.,Akkuratova, O. L.,Sergeev, V. A.,Nedel'kin, V. I.,Yuferov, E. A.
, p. 2560 - 2562 (1984)
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Simple, extremely fast, and high-yielding oxidation of thiols to disulfides
Alam, Ashraful,Takaguchi, Yutaka,Tsuboi, Sadao
, p. 1329 - 1333 (2005)
Results of oxidation of thiols to disulfides with 1,3-dibromo-5,5-dimethyl- hydantoin (DBDMH) are described. A simple addition of 0.20-0.25 mol equivalent of solid DBDMH to thiol in chloroform at room temperature yielded the disulfides in excellent yield. The reaction is extremely fast and gave no other oxidized side products. Copyright Taylor & Francis, Inc.
Haloacid/dimethyl sulfoxide-catalyzed synthesis of symmetrical disulfides by oxidation of thiols
Natarajan, Palani,Sharma, Himani,Kaur, Mandeep,Sharma, Pooja
, p. 5578 - 5582 (2015)
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.
A novel copper-catalyzed, one-pot synthesis of symmetric organic disulfides from alkyl and aryl halides: Potassium 5-methyl-1,3,4-oxadiazole-2-thiolate as a novel sulfur transfer reagent
Soleiman-Beigi, Mohammad,Mohammadi, Fariba
, p. 7028 - 7030 (2012)
A new method is reported for the synthesis of symmetric diaryl and dialkyl disulfides from aryl and alkyl halides in the presence of copper using potassium 5-methyl-1,3,4-oxadiazole-2-thiolate as the base, ligand, and sulfur-transfer reagent.
A novel dual-nano assisted synthesis of symmetrical disulfides from aryl/alkyl halides
Devi, Namita,Hazarika, Sukanya,Gogoi, Prasanta,Barman, Pranjit
, p. 1927 - 1938 (2018)
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%.
Easy and rapid method for disulfide syntheses using nanophase-manganese (VII) oxide coated clay
Gondi, Sudershan R.,Son, David Y.,Biehl, Edward R.,Vempati, Rajan K.
, p. 34 - 39 (2010)
Disulfide bond formation by the oxidation of several thiol compounds using nanophase manganese (VII) oxide coated clay (NM7O coated clay) in chlorinated, nonchlorinated (toluene), and polar solvents (water) is described. During the process, nitro and methoxy groups remain unaffected. The NM7O coated clay is easily prepared, stable, and inexpensive to manufacture. Furthermore, this and other studies prove that NM7O coated clay properties, i.e., mineralogy, chemical, and reactivity, are different from KMnO4. This rapid and facile synthesis coupled with the use of the recyclable NM7O coated clay catalyst will save energy due to low temperature and rapid reaction times, as well as minimal disposal problems, thus decreasing production costs.
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Meier,Menzel
, p. 267 (1972)
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Semisynthetic enzymes in asymmetric synthesis: Enantioselective reduction of racemic hydroperoxides catalyzed by seleno-subtilisin
Haering, Dietmar,Schueler, Ellen,Adam, Waldemar,Saha-Moeller, Chantu R.,Schreier, Peter
, p. 832 - 835 (1999)
The serine protease subtilisin was chemically converted into the peroxidase-active seleno-subtilisin. This semisynthetic enzyme catalyzes the enantioselective reduction of racemic hydroperoxides in the presence of thiophenols to yield optically active hydroperoxides and alcohols on the semipreparative scale. The kinetic parameters and enantioselectivities of seleno-subtilisin-catalyzed reduction of various chiral hydroperoxides were determined. The catalytic efficiency of this semisynthetic enzyme is comparable to that of the native horseradish peroxidase. The sense in the enantioselectivity of the seleno-subtilisin is opposite to the natural enzymes previously used in the synthesis of optically active hydroperoxides. Consequently, the semisynthetic enzyme selenosubtilisin complements the naturally available peroxidases for the asymmetric synthesis of both enantiomers.
Oxidation of thiols to bisulfides using silica chloride as a heterogeneous catalyst
Sathe, Manisha,Ghorpade, Ramarao,Kaushik, Mahabir Parshad
, p. 1048 - 1049 (2006)
Silica chloride is used as a selective and effective heterogeneous catalyst for the rapid conversion of thiols to disulfides with quantitative yields in a very short period of time. Copyright
A mild and efficient protocol for oxidation of thiols to disulfides in water
Dewan, Anindita,Bora, Utpal,Kakati, Dilip K.
, p. 231 - 234 (2012)
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.
Oxidation by Chemical Manganese Dioxide. Part 2.1 Simple and High-yielding Synthesis of Symmetrical Disulfides via the Oxidative Coupling of Thiols
Hirano, Masao,Yakabe, Sigetaka,Chikamori, Hideki,Clark, James H.,Morimoto, Takashi
, p. 310 - 311 (1998)
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.
A supramolecular microgel glutathione peroxidase mimic with temperature responsive activity
Yin, Yanzhen,Jiao, Shufei,Lang, Chao,Liu, Junqiu
, p. 3374 - 3385 (2014)
Glutathione peroxidase (GPx) protects cells from oxidative damage by scavenging surplus reactive oxygen species (ROS). Commonly, an appropriate amount of ROS acts as a signal molecule in the metabolism. A smart artificial GPx exhibits adjustable catalytic activity, which can potentially reduce the amount of ROS to an appropriate degree and maintain its important physiological functions in metabolism. To construct an optimum and excellent smart artificial GPx, a novel supramolecular microgel artificial GPx (SM-Te) was prepared based on the supramolecular host-guest interaction employing the tellurium-containing guest molecule (ADA-Te-ADA) and the cyclodextrin-containing host block copolymer (poly(N-isopropylacrylamide)-b-[polyacrylamides-co-poly(6-o-(triethylene glycol monoacrylate ether)-β-cyclodextrin)], PPAM-CD) as building blocks. Subsequently, based on these building blocks, SM-Te was constructed and the formation of its self-assembled structure was confirmed by dynamic light scattering, NMR, SEM, TEM, etc. Typically, benefitting from the temperature responsive properties of the PNIPAM scaffold, SM-Te also exhibited similar temperature responsive behaviour. Importantly, the GPx catalytic rates of SM-Te displayed a noticeable temperature responsive characteristic. Moreover, SM-Te exhibited the typical saturation kinetics behaviour of a real enzyme catalyst. It was proved that the changes of the hydrophobic microenvironment and the pore size in the supramolecular microgel network of SM-Te played significant roles in altering the temperature responsive catalytic behaviour. The successful construction of SM-Te not only overcomes the insurmountable disadvantages existing in previous covalent bond crosslinked microgel artificial GPx but also bodes well for the development of novel intelligent antioxidant drugs. This journal is the Partner Organisations 2014.
Unsymmetrical Disulfide Synthesis through Photoredox Catalysis
Dethe, Dattatraya H.,Srivastava, Aparna,Dherange, Balu D.,Kumar, B. Vijay
, p. 3020 - 3025 (2018)
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.).
Hammett correlations as test of mechanism of CO-induced disulfide elimination from dinitrosyl iron complexes
Pulukkody, Randara,Kyran, Samuel J.,Drummond, Michael J.,Hsieh, Chung-Hung,Darensbourg, Donald J.,Darensbourg, Marcetta Y.
, p. 3795 - 3802 (2014)
The displacement of RS from [(NHC)(SPh)Fe(NO)2] (NHC = N-heterocyclic carbene) by carbon monoxide follows associative kinetics, rate = k [CO]1 [(NHC)(SPh)Fe(NO)2]1, resulting in reduction of the oxidized form of
Aryl diazonium salt and thioacetamide: A catalyst free, efficient blend of an inexpensive arylating agent with "s" surrogate for sulphide synthesis
Bhojane, Jeevan Manohar,Sarode, Sachin Ashok,Nagarkar, Jayashreemilind
, p. 90046 - 90050 (2016)
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.
Construction of starch-based bionic glutathione peroxidase and its catalytic mechanism
Jiao, Shu-Fei,Liang, Xing-Tang,Liu, Yong-Xian,Liu, Zi-Jie,Yin, Yan-Zhen,Zhang, Rui-Rui,Zheng, Yun-Ying
, (2022/02/16)
Glutathione peroxidase (GPx) is an important selenium-containing antioxidant enzyme in human body. The preparation of bionic GPx and the mimicry of its catalytic behavior are of great significance for the development of antioxidant drugs. At present, most of the reported biomimetic selenoenzymes based on the macromolecular are difficult to be degraded, which restricts their applications in the fields such as medical treatment, health care, and functional food. In order to solve this issue, herein, the octenyl succinic acid-modified starch (OSA starch) prepared by the esterification of waxy corn starch was used as the raw material, a new selenium-functionalized starch (Se-starch) was synthesized via the reaction of OSA starch and sodium hydrogen selenide. Such Se-starch, as a biomimetic selenoenzyme, was characterized using 1H NMR, EDS, XPS, SEM, XRD, and FT-IR. The Se-starch with a catalytic activity of 2.48?μM·min?1 showed a typical catalysis behavior of saturated kinetic and enzymology. This catalytic activity is 1.04 × 105 times higher than that of the PhSeSePh, a representative small molecule bionic GPx. The study of catalytic mechanism revealed that the octenyl succinate molecule bonded on the starch endowed it with hydrophobic micro-environments, which benefited the binding of hydrophobic substrates, and consequently increased the catalytic activity. This work not only provided a new idea for constructing natural polymers-based bionic GPx, but also offered an important theoretical basis for the development of new antioxidant drugs and functional foods.
Photochemical metal-free aerobic oxidation of thiols to disulfides
Spiliopoulou, Nikoleta,Kokotos, Christoforos G.
supporting information, p. 546 - 551 (2021/01/28)
Thiol oxidation to disulfides is an area of great importance in organic synthesis, both for synthetic and biological purposes. Herein, we report a mild, inexpensive and green photochemical approach for the synthesis of both symmetrical and non-symmetrical disulfides, using metal-free and environmentally friendly conditions. Utilizing phenylglyoxylic acid as the photoinitiator, common household bulbs as the light source and a simple inorganic salt as the additive, a versatile oxidation of thiols leading to products in excellent yields is described. This journal is
