- Palladium-Catalyzed Picolinamide-Directed Benzylic C(sp3)?H Chalcogenation with Diaryl Disulfides and Diphenyl Diselenide
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The first palladium-catalyzed direct benzylic C(sp3)?H chalcogenation with diaryl disulfides and diphenyl diselenide has been established. The coupling reaction proceeds between the thioether radical and palladiumcycle intermediate. Picolinamide serves as an excellent directing group for the C?H activation of benzylic C(sp3)?H and can be easily removed. The current protocol exhibits a relatively broad substrate scope and high functional group compatibility. A mechanistic study indicates that palladium(IV) intermediate is probably formed during the course of the reaction. (Figure presented.).
- Wang, Kai,Hou, Jiahao,Zhang, Changjun,Cheng, Ke,Bai, Renren,Xie, Yuanyuan
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supporting information
p. 2947 - 2952
(2020/06/17)
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- Preparation method for symmetric diaryl disulfide
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The invention discloses a preparation method for symmetric diaryl disulfide. The preparation method comprises the following steps: using aromatic hydrocarbon as shown in a general formula (I) as a rawmaterial and reacting with chlorosulfonic acid to generate aryl chlorosulfonic acid, and reacting with sulfoxide chloride to synthesize aryl sulfonyl chloride as shown in a general formula (II); andpreparing the symmetric diaryl disulfide as shown in a general formula (III) under the action of a reducing agent through a reduction reaction by the aryl sulfonyl chloride as shown in the general formula (II). The disclosed preparation method for the symmetric diaryl disulfide has many advantages of low toxicity of the reaction raw material, short reaction time, cheap reagents and easy acquisition, convenient separation and purification and the like, and has very high application value and industrial production value.
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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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- Conversion of organic halides to disulfanes using KCN and CS2
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A sulfur transfer reagent was produced in situ upon stirring a mixture of KCN and CS2 in DMF at r.t. for 15 min, which after heating with an alkyl halide or aryl halide and CuI gave the corresponding symmetric dialkyl or diaryl disulfide, respectively, in high to excellent yields.
- Abbasi, Mohammad,Nowrouzi, Najmeh,Borazjani, Saeedeh Ghassab
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p. 4251 - 4254
(2017/10/11)
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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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- Investigation on the reduction of sulfonyl chlorides with sulfur dioxide in water as solvent
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An operationally simple and environmentally benign method for reductive coupling of sulfonyl chlorides to the corresponding disulfides has been developed. Sulfonyl chlorides can be rapidly reduced with SO2/KI/ H2SO4 system in moderate to good yields at 80 C in water. Graphical Abstract: [Figure not available: see fulltext.]
- Zhao, Qian,Qian, Chao,Chen, Xin-Zhi
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p. 1547 - 1550
(2013/10/22)
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- An improved method for the synthesis of disulfides by periodic acid and sodium hydrogen sulfite in water
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An improved method for the synthesis of disulfide in water by using periodic acid and sodium hydrogen sulfite was developed.
- Khan, Khalid M.,Taha, Muhammad,Rahim, Fazal,Ali, Muhammad,Jamil, Waqas,Perveen, Shahnaz,Iqbal Choudhary
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experimental part
p. 415 - 419
(2011/03/22)
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- Synthesis of diaryl disulfides via the reductive coupling of arylsulfonyl chlorides
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A facile synthesis of diaryl disulfides from arylsulfonyl chlorides in the presence of triphenylphosphine has been developed.
- Kabalka, George W.,Reddy, Marepally Srinivasa,Yao, Min-Liang
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scheme or table
p. 7340 - 7342
(2010/03/01)
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- Temperature-controlled selective reduction of arenesulfonyl chlorides promoted by samarium metal in DMF
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Promoted by samarium in DMF, arenesulfonyl chlorides can be selectively reduced to diaryldisulfones, diarylthiosulfonates and diaryldisulfides in good to excellent yields by reaction temperature control without the need to pretreat or activate the metallic samarium.
- Liu, Yongjun,Zhang, Yongmin
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p. 4291 - 4294
(2007/10/03)
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- Practical and scaleable syntheses of 3-hydroxythiophenol
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3-Hydroxythiophenol is a versatile intermediate for the synthesis of medicinal and heterocyclic compounds. Two novel and practical syntheses of 3-hydroxythiophenol are achieved using readily available and inexpensive starting materials. An overall cost comparison of these syntheses is also given.
- Zhang, Mingbao,Ryckman, David,Chen, Guohua,MacMillan, Eric,Duquette, Jason
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p. 112 - 116
(2007/10/03)
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- Reaction of carbon black with diazonium salts, resultant carbon black products and their uses
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Processes for coloring a fiber or textile by adding a carbon black product having an organic group attached to the carbon black. In one process at least one diazonium salt reacts with a carbon black in the absence of an externally applied electric current sufficient to reduce the diazonium salt. In another process at least one diazonium salt reacts with a carbon black in a protic reaction medium. Carbon black products which may be prepared according to process of the invention are described as well as uses of such carbon black products in plastic compositions, rubber compositions, paper compositions, and textile compositions.
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- Electron-Deficient Isoalloxazines: Model Systems for Disulfide Prodrug Formation
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Drugs which contain a thiol functionality may be enzymatically or nonenzymatically oxidized to reactive metabolites, some of which cause adverse reactions.The synthesis of disulfide prodrugs to obviate unwanted drug side effects requires the development of novel catalysts.Herein, we describe the synthesis, structure-activity relationship, and mechanism investigations of the oxidation of model thiophenols with isoalloxazine disulfide formation catalysts. m-Nitrothiophenol (31) reacts with the electron-deficient 8-cyano-N-3-(mercaptoalkyl)-10-phenylisoalloxazines (5-8) and non-electron-deficient N-3-(mercaptoalkyl)-10-methylisoalloxazines (1-4) to produce m-nitrothiophenol disulfide. m-Nitrothiophenol (31) reacts with electron-deficient 8-cyano-10-phenyl-3-isoalloxazinepentanoic acid (10) or 10-methyl-3-isoalloxazinepentanoic acid (9) to form m-nitrothiophenol disulfide at a reduced rate, or not at all, respectively.Of the substituted isoalloxazines studied, electron-deficient isoalloxazines containing an N-3-mercaptoalkyl side chain were most efficient at catalyzing m-nitrothiophenol disulfide formation.Non-electron-deficient isoalloxazines without an N-3-alkyl mercaptan side chain (9) did not catalyze m-nitrothiophenol oxidation.Electron-deficient isoalloxazines without N-3-alkyl mercaptan side chains catalyzed m-nitrothiophenol oxidation at 1/20 the rate for isoalloxazine 5.From kinetic and product studies, the differences in catalytic activity of 1-10 were judged to be due to changes in the chemical properties of the isoalloxazines and the ability to stabilize intramolecular thiol attack on the C(4a)-N(5) bond of the isoalloxazine.Electron-deficient isoalloxazines may be useful catalysts for the syntheses of disulfide prodrugs.
- Cashman, John R.,Liu, Yan
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p. 2049 - 2055
(2007/10/02)
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- Anti-tumor prodrugs
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There are disclosed anti-tumor prodrug compounds that are (a) disulfide benzylcarbamate derivatives of amino (primary and secondary) containing anti-tumor drugs, and (b) disulfide benzylcarbonate derivatives of hydroxyl containing anti-tumor drugs. The prodrug compounds release active, free drug as a result of undergoing reductive cleavage of the disulfide moiety and subsequent chemical fragmentation.
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