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1.
An Efficient and Selective Solid State Oxidation of Thiols to Disulfides with Quinolinium Fluorochromate on Silica Gel 总被引:1,自引:0,他引:1
Tajbakhsh Mahmood Mohammadpoor-Baltork Iraj Alimohammadi Kamal 《Monatshefte für Chemie / Chemical Monthly》2003,134(12):1571-1575
Summary. Various kinds of aliphatic (cyclic and acyclic), aromatic, and heterocyclic thiols are converted into the corresponding disulfides by quinolinium fluorochromate (QFC) on silica-gel in excellent yields. Selective oxidation of thiols in the presence of sulfides is also achieved under solid phase conditions. 相似文献
2.
Mohammad M. Mojtahedi M. Saeed Abaee Majid M. Heravi Farahnaz K. Behbahani 《Monatshefte für Chemie / Chemical Monthly》2007,138(1):95-99
Summary. Amines with different stereoelectronic nature were efficiently acylated at room temperature using acetic anhydride in the
presence of no solvent or additive. Various thiols also react equally well under the same conditions. Chemoselective protection
of amines in the presence of thiols, alcohols, and phenols and of thiols in the presence of alcohols, and phenols were achieved
using competitive experiments. 相似文献
3.
Rahman Hosseinzadeh Mahmood Tajbakhsh Hamid Khaledi Keivan Ghodrati 《Monatshefte für Chemie / Chemical Monthly》2007,138(9):871-873
Summary. Ethylenebis(N-methylimidazolium) chlorochromate was prepared by addition of N-methylimidazole to 1,2-dibromoethane to form the corresponding dibromide salt and subsequent treatment of this salt with
CrO3 in 6N HCl solution. It is a stable yellow-orange solid, which oxidized thiols to the corresponding disulfides at room temperature.
Selective oxidation of thiols in the presence of sulfides and hydroxyl groups was also achieved with this reagent. 相似文献
4.
I. Jabre M. Saquet A. Thuillier 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):283-285
Abstract Convenient syntheses of S-aryldithioesters and thioamides are described: thus, thiols and amines are readily thioacylated with the S-borondithioester formed in situ, by the mild reaction of a dithioacid with 9-BBN. 相似文献
5.
Summary. Molecular oxygen is used as an efficient oxidant for the oxidative coupling of thiols to disulfides in subcritical water in
the absence of catalysts. The procedure utilizes water and does not require support materials and metal salts providing high
yields (>90%). 相似文献
6.
Kiyoharu Nishide Shin-ichi Ohsugi Tetsuo Miyamoto Kamal Kumar Manabu Node 《Monatshefte für Chemie / Chemical Monthly》2004,135(2):189-200
Summary. Development of new odorless thiols (dodecanethiol, 4-n-heptylphenylmethanethiol, 4-trimethylsilylphenylmethanethiol, 4-trimethylsilylbenzenethiol) and an odorless sulfide (1-methylsulfanyldodecane) and their applications to dealkylation, Michael addition, Swern oxidation, and Corey-Kim oxidation are described. 相似文献
7.
A. V. Bodrov L. E. Nikitina V. A. Startseva O. A. Lodochnikova R. Z. Musin O. I. Gnezdilov 《Russian Journal of General Chemistry》2013,83(1):80-86
BF3-catalyzed addition of some thiols to (+)-camphene was examined. Reactions with aromatic thiols and hetaryl thiols result in terpene sulfides of camphene or bornane structure in accordance with the Markovnikov’s rule, whereas with remain thiols the reaction proceeds against the Markovnikov’s rules preserving the original structure of the molecule. 相似文献
8.
Angelo Zinellu Antonio Lepedda Jr. Salvatore Sotgia Elisabetta Zinellu Giommaria Marongiu Maria Franca Usai Leonardo Gaspa Pierina De Muro Marilena Formato Luca Deiana Ciriaco Carru 《Journal of separation science》2010,33(1):126-131
We describe a new method for the quantification of low molecular weight thiols, as homocysteine, cysteine, cysteinylglycine, glutamylcysteine and glutathione bound to human plasma albumin. After albumin isolation and purification by SDS‐PAGE, thiols were freed from protein with tri‐n‐butylphosphine and successively derivatized with 5‐iodoacetamidofluorescein. Samples were then injected and quantified in about 18 min by CE with laser induced fluorescence detection. Precision tests indicate a good repeatability of the method both for migration times (RSD<0.63%) and areas (RSD<2.98%). The method allows to measure all five low molecular weight thiols released from just 3 μg of albumin thus improving the other described methods in which only three or four thiols were detected. Due to the elevated sensitivity (LOD of 0.3 pM for all thiols), also low molecular weight thiols bound to albumin filtered in tissues could be quantified. 相似文献
9.
Ahmad Shaabani Naser Safari Samad Shoghpour Ali Hossein Rezayan 《Monatshefte für Chemie / Chemical Monthly》2008,139(6):613-615
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.
Correspondence: Ahmad Shaabani, Department of Chemistry, Shahid Beheshti University, P.O. Box 19396, 4716 Tehran, Iran. 相似文献
10.
Summary. A mixture of cobalt(II) and manganese(II) salts of 4-aminobenzoic acid supported on silica gel catalyses the oxidation of thiols to disulfides in the presence of oxygen or air. 相似文献
11.
The performance of preheated glassy carbon electrode modified with carbon nanotubes is described. First glassy carbon electrode is heated for 5 min at 50 °C, then abrasive immobilization of multiwall carbon nanotubes on a preheated glassy carbon electrode was achieved by gentle rubbing of electrode surface on a filter paper supporting carbon nanotubes. Carbon nanotubes (CNTs)-modified glassy carbon electrodes exhibit strong and stable electrocatalytic response toward thiols oxidation in wide pH range. These properties permit an important decrease in over voltage for the oxidation of thiocytosine, glutathione and l-cysteine, as well as a dramatic increase in the peak currents in comparison with bare glassy carbon electrode. Furthermore, the thiols amperometric response of the coated electrodes is extremely stable, with more than 95% of the initial activity after 30 min stirring of 0.1 mM thiols. The electrocatalytic behavior is further exploited as a sensitive detection scheme for thiols detection by hydrodynamic amperometry. The substantial decrease in the overvoltage of the thiols oxidation associated with a stable amperometric response and antifouling properties of nanotubes films allow the development of highly sensitive thiols sensor without using any redox mediator. Such ability of carbon nanotubes to promote the thiols electron transfer reaction, short response time (5 s) and long-term stability, low detection limit, extended linear concentration range, high sensitivity suggest great promise for thiols amperometric sensors and detector for chromatographic analysis of thiol derivatives. 相似文献
12.
We presented the design, synthesis and preliminary evaluation of the 2,4-dinitrobenzenesulfonate (DNBS) of imidazo[1,5-α]pyridine derivative, NIPY-DNBS, as a turn-on fluorescent probe for the detection of thiols in aqueous solution. The reaction mechanism was confirmed by means of fluorescence, absorption and HRMS. The large Stokes shift (201 nm), high sensitivity (the detection limit for Cys was calculated to be as low as 0.17 μM) and fast response (10 min) of NIPY-DNBS make it a practical and reliable method for fluorescence imaging. Furthermore, application of NIPY-DNBS for the selective detection of intracellular thiols has been successfully demonstrated in living A549 cells. 相似文献
13.
Kinetic Resolution of sec‐Thiols by Enantioselective Oxidation with Rationally Engineered 5‐(Hydroxymethyl)furfural Oxidase
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M. Sc. Mathias Pickl Alexander Swoboda Dr. Elvira Romero Dr. Christoph K. Winkler Dr. Claudia Binda Prof. Dr. Andrea Mattevi Prof. Dr. Kurt Faber Prof. Dr. Marco W. Fraaije 《Angewandte Chemie (International ed. in English)》2018,57(11):2864-2868
Various flavoprotein oxidases were recently shown to oxidize primary thiols. Herein, this reactivity is extended to sec‐thiols by using structure‐guided engineering of 5‐(hydroxymethyl)furfural oxidase (HMFO). The variants obtained were employed for the oxidative kinetic resolution of racemic sec‐thiols, thus yielding the corresponding thioketones and nonreacted R‐configured thiols with excellent enantioselectivities (E≥200). The engineering strategy applied went beyond the classic approach of replacing bulky amino acid residues with smaller ones, as the active site was additionally enlarged by a newly introduced Thr residue. This residue established a hydrogen‐bonding interaction with the substrates, as verified in the crystal structure of the variant. These strategies unlocked HMFO variants for the enantioselective oxidation of a range of sec‐thiols. 相似文献
14.
Barahman Movassagh Mohammad Soleiman-Beigi 《Monatshefte für Chemie / Chemical Monthly》2008,139(8):927-930
Symmetrical and unsymmetrical trithiocarbonates were prepared by a simple and efficient one-pot reaction of thiols, carbon
disulfide, and alkyl halides in the presence of triethylamine in water at room temperature.
Correspondence: Barahman Movassagh, Department of Chemistry, K.N. Toosi University of Technology, P.O. Box 16315–1618, Tehran, Iran. 相似文献
15.
Masahiko Hayashi Ken-ichi Okunaga Shunsuke Nishida Kenjiro Kawamura Kazuo Eda 《Tetrahedron letters》2010,51(51):6734-6736
Efficient oxidative transformation of thiols to disulfides took place in the presence of activated carbon under an oxygen (or air) atmosphere. The present oxidation method is available not only for a variety of thiols such as simple aromatic and aliphatic thiols but also for 3,4-dihydropyrimidin-2(1H)-thiones and N-Boc-l-cysteine. 相似文献
16.
Srivastava A 《Talanta》1982,29(1):31-35
Iodoso derivatives, e.g., m- and p-chlorophenyl, m- and p-methylphenyl and p-nitrophenyl-iodosoacetates and o-diacetoxyiodobenzoate, have been thoroughly investigated as oxidants and are proposed as analytical reagents for the determination of thiols, thioureas, isothiocyanates, organic sulphides, disulphides, xanthates, dithiocarbamates, amines and alcohols in aqueous and non-aqueous (acetic acid, acetonitrile, dimethylformamide) media. The error of the determination of thiols is 0.2% thioureas 0.5%, organic sulphides and disulphides 0.4%, isothiocyanates 0.4%, dithiocarbamates 0.4%, and xanthates 0.5%. All the methods are precise to 0.2-0.5%. It is also shown that the properties of the o-derivatives differ markedly from those of the m- and p-derivatives. The o-derivatives contain a 1-substituted 1,2-benzoiodoxilin-3-one ring system. The stability of this system is apparently associated with the size of the five-membered ring; other compounds in which iodine is apparently part of larger rings are less stable. o-Diacetoxyiodobenzoate appears to be the best analytical reagent of the iodoso series. The m- and p-iodosobenzoates are found unsuitable for quantitative oxidation of cysteine. 相似文献
17.
Palladium‐Catalyzed γ‐C(sp3)−H Arylation of Thiols by a Detachable Protecting/Directing Group
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Likun Jin Jianchun Wang Prof. Dr. Guangbin Dong 《Angewandte Chemie (International ed. in English)》2018,57(38):12352-12355
Reported herein is a palladium‐catalyzed, directed γ‐C(sp3)?H arylation of protected thiols. The key is to utilize Michael acceptors as a dual reagent to install a protecting/directing group on thiols by a thiol‐Michael click reaction, and remove it later under basic conditions. The C?H arylation proceeds with high functional‐group tolerance and the deprotected thiols can be further transformed into other sulfur‐containing compounds. This unique mode of activation could open the door for site‐selective functionalization of thiols or other sulfur‐containing compounds at unactivated positions. 相似文献
18.
The kinetics of the catalytic oxidation reactions of thiol compounds with molecular oxygen in aqueous solutions in the presence of copper ions was studied in relation to the structures of oxidized thiols and the pH of the solution. A modified procedure used for the determination of [O2] allowed us to obtain the kinetic characteristics of more than 30 thiols over a wide pH range. We found that weakly chelating thiols exhibited a first order of reaction with respect to [Cu+] and [O2] under conditions when the [(Cu+)(RS–)2] complex occurred. In the oxidation of strongly chelating thiols in an alkaline medium, the order of reaction with respect to [Cu+] was equal to 2, and the rate of reaction was independent of [O2]. We found that the introduction of small amounts of strongly chelating thiols into Cu+ solutions containing difficult-to-oxidize mercaptans resulted in a dramatic acceleration of mercaptan oxidation. We hypothesized that O2 was effectively bound to the [(Cu+)(RS–)2] complexes in an alkaline medium in the case of strongly chelating thiols, and this was not the case with the complexes of weakly chelating thiols. 相似文献
19.
Xianglin TangWeimin Liu Jiasheng WuWenwen Zhao Hongyan ZhangPengfei Wang 《Tetrahedron letters》2011,52(40):5136-5139
A TCNQ-based triphenylamine derivative (1) with strong intramolecular charge transfer (ICT) character was designed as a colorimetric sensor for thiols. Upon addition of thiols, the absorption spectrum of sensor 1 in aqueous solution was remarkably changed because the adduct of 1 with thiol decreased its ICT character. Sensor 1 showed highly selective and sensitive sensing ability toward thiols over other analytes. This selectivity could be easily observed by naked eyes, indicating that sensor 1 is a potential colorimetric sensor for thiols. 相似文献
20.
Firdaus Yhaya Arlingga Sutinah Andrew M. Gregory Mingtao Liang Martina H. Stenzel 《Journal of polymer science. Part A, Polymer chemistry》2012,50(19):4085-4093
The polymerization of vinyl methacrylate (VMA) allows the synthesis of polymers with pendant double bonds. When this polymerization was undertaken in the presence of 2‐cyanopropyl dithiobenzoate as reversible addition–fragmentation chain transfer agent, it led almost exclusively to vinylester functional sidegroups, which were available for further reactions. The vinylester functionality could not be functionalized using common thiol‐ene catalysts, but could be activated using Candida antarctica lipase B (CAL‐B) (Novozyme 435). The reaction between PVMA and various thiols in N, N‐dimethyl formamide in the presence of CAL‐B led exclusively to the formation of the anti‐Markovnikov product. The rate of reaction between PVMA and 1‐butanethiol was monitored using 1H NMR. The reaction was complete within 72 h. Similar results were obtained with other small‐sized thiols such as 2‐mercaptoethanol, 3‐mercaptopropionic acid, and 2‐(trimethylsilyl)ethanethiol, while more bulky thiols, such as secondary thiols, thiols with long alkyl chains, and sterically demanding thiols, such as mono(6‐deoxy‐6‐mercapto)‐β‐cyclodextrin, only led to lower conversions. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献