- Methyl-transfer reaction to alkylthiol catalyzed by a simple vitamin B 12 model complex using zinc powder
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The catalytic methyl-transfer reaction from methyl tosylate to 1-octanethiol was carried out in the presence of a simple vitamin B12 model complex, [Co(III){(C2C3)(DO)(DOH)pn}Br 2], with zinc powder as the reducing reagent at 50°C. Such a catalytic reaction proceeded via the formation and dissociation of a cobalt-carbon bond in the simple vitamin B12 model complex under non-enzymatic conditions. The mechanism for the methyl-transfer reaction was investigated by electronic and mass spectroscopies. The Co(I) species, which is generated from the reduction of the catalyst by the zinc powder, and its methylated CH3-Co complex were found to be indispensable intermediates.
- Pan, Ling,Tahara, Keishiro,Masuko, Takahiro,Hisaeda, Yoshio
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Read Online
- Electrochemical methyl-transfer reaction to alkylthiol catalyzed by hydrophobic vitamin B12
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The catalytic methyl-transfer reaction from methyl tosylate to 1-octanethiol was carried out in the presence of heptamethyl cobyrinate perchlorate, hydrophobic vitamin B12, under electrochemical conditions at -1.0 V vs. Ag/AgCl using a carbon-f
- Pan, Ling,Shimakoshi, Hisashi,Hisaeda, Yoshio
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Read Online
- Synthesis of Aryl Methyl Sulfides from Arysulfonyl Chlorides with Dimethyl Carbonate as the Solvent and C1 Source
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A new procedure for the synthesis of aryl methyl sulfides from dimethyl carbonate (DMC) and arylsulfonyl chlorides has been achieved. In this strategy, DMC plays a dual role as both, C1 building block and green solvent. Arylsulfonyl chlorides served as the sulfur precursors, and a variety of aryl methyl sulfides were obtained in moderate to excellent yields with good functional group tolerance. Additionally, alkylsulfonyl chloride and dibenzyl carbonate are proven to be suitable substrates as well.
- Miao, Ren-Guan,Qi, Xinxin,Wu, Xiao-Feng
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supporting information
p. 5219 - 5221
(2021/10/19)
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- Synthesizing process of flutriafol key intermediate 1-(2-fluorophenyl)-1-(4-fluorophenyl)ethylene oxide
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The invention discloses a synthesizing process of a flutriafol key intermediate 1-(2-fluorophenyl)-1-(4-fluorophenyl)ethylene oxide. The synthesizing process comprises the following steps: mixing 1-bromooctane and sodium methyl mercaptide, adding tetrabutylammonium bromide, stirring for reacting, adding water for standing and layering to form an organic phase and a water phase after the reaction is finished, performing skimming to remove the water phase, washing the organic phase with water, performing drying and suction filtration, dissolving a prepared product and dimethyl sulfate in an organic solvent for reacting, and removing the organic solvent from a reaction solution to obtain sulfur-onium salt after the reaction is finished; adding the sulfur-onium salt, inorganic alkali and 2,4'-difluoro benzophenone into a solvent, stirring for reacting, adding water for standing and layering to form an organic phase and a water phase after the reaction is finished, performing skimming to remove the water phase, washing the organic phase with water, performing dehydration, drying and suction filtration, and removing the solvent from filtrate to obtain the 1-(2-fluorophenyl)-1-(4-fluorophenyl)ethylene oxide. By adopting the synthesizing process, the alkali is screened, and sodium hydroxide is taken as an alkali medium, thereby improving the reaction yield; moreover, methyl n-octyl sulfide has low odor.
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Paragraph 0013; 0014
(2019/02/25)
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- The energy-transfer-enabled biocompatible disulfide–ene reaction
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Sulfur-containing molecules participate in many essential biological processes. Of utmost importance is the methylthioether moiety, present in the proteinogenic amino acid methionine and installed in tRNA by radical-S-adenosylmethionine methylthiotransferases. Although the thiol–ene reaction for carbon–sulfur bond formation has found widespread applications in materials or medicinal science, a biocompatible chemo- and regioselective hydrothiolation of unactivated alkenes and alkynes remains elusive. Here, we describe the design of a general chemoselective anti-Markovnikov hydroalkyl/aryl thiolation of alkenes and alkynes—also allowing the biologically important hydromethylthiolation—by triplet–triplet energy transfer activation of disulfides. This fast disulfide–ene reaction shows extraordinary functional group tolerance and biocompatibility. Transient absorption spectroscopy was used to study the sensitization process in detail. The hereby gained mechanistic insights were successfully employed for optimization of the catalytic system. This photosensitized transformation should stimulate bioimaging applications and carbon–sulfur bond-forming late-stage functionalization chemistry, especially in the context of metabolic labelling.
- Teders, Michael,Henkel, Christian,Anh?user, Lea,Strieth-Kalthoff, Felix,Gómez-Suárez, Adrián,Kleinmans, Roman,Kahnt, Axel,Rentmeister, Andrea,Guldi, Dirk,Glorius, Frank
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p. 981 - 988
(2018/08/31)
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- Sulfonium salt type chloramine antibacterial agent and synthetic method thereof
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The invention belongs to the technical field of chemical synthesis and application of chloramine antibacterial agents, and provides a sulfonium salt type chloramine antibacterial agent and a syntheticmethod thereof. A preparation method of the antibacterial agent comprises the following steps: taking bromoalkyl 5,5-dimethylhydantoin and thioether as raw materials to prepare a sulfonium salt bromide chloramine precursor compound IV; reacting the precursor compound IV with t-butyl hypochlorite at normal temperature after ion exchange to obtain an antibacterial agent compound I. The antibacterial agent disclosed by the invention introduces a cationic structural unit-sulfonium salt group into a hydrophobic chain chloramine group, so that water solubility of the chloramine antibacterial agentis greatly improved and structure stability of the chloramine antibacterial agent is significantly enhanced. By using staphylococcus aureus as a model strain, the antibacterial test result shows thatthe bactericidal activity of the prepared sulfonium salt type chloramine compound is better than that of a mono-quaternary ammonium salt type chloramine compound.
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Paragraph 0038; 0039
(2018/11/22)
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- Hydrogenation of sulfoxides to sulfides under mild conditions using ruthenium nanoparticle catalysts
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The first demonstration of the hydrogenation of sulfoxides under atmospheric H2 pressure is reported. The highly efficient reaction is facilitated by a heterogeneous Ru nanoparticle catalyst. The mild reaction conditions enable the selective hydrogenation of a wide range of functionalized sulfoxides to the corresponding sulfides. The high redox ability of RuO x nanoparticles plays a key role in the hydrogenation.
- Mitsudome, Takato,Takahashi, Yusuke,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
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supporting information
p. 8348 - 8351
(2014/08/18)
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- Highly efficient deoxygenation of sulfoxides using hydroxyapatite-supported ruthenium nanoparticles
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We report the first example of the deoxygenation of sulfoxides using heterogeneous catalysts with alcohols as environmentally friendly reducing reagents. Hydroxyapatitesupported Ru nanoparticles (RuNPs/HAP) act as a highly efficient and reusable heterogeneous catalyst for deoxygenation of sulfoxides using alcohols as reductants. The catalytic activity of Ru nanoparticles is outstanding compared to other metal nanoparticles such as Pt, Pd, Rh, and Au nanoparticles. RuNPs/HAP can also catalyze the selective deoxygenation of various sulfoxides, giving the corresponding sulfides in excellent yields.
- Takahashi, Yusuke,Mitsudome, Takato,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
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supporting information
p. 420 - 422
(2014/04/17)
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- One-pot reduction of sulfoxides with NaBH4, CoCl2. 6H2O catalyst, and moist alumina
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Sulfoxides are reduced by a combination of sodium borohydride, a catalytic amount of cobalt(II) chloride hexahydrate, and chromatographic neutral alumina preloaded with a small amount of water (moist alumina) in hexane to produce the corresponding sulfides in good to excellent yields under mild conditions. An interesting structural influence of sulfoxides on their reactivity is observed. Copyright
- Yakabe, Shigetaka,Hirano, Masao,Morimoto, Takashi
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experimental part
p. 2251 - 2255
(2011/06/27)
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- Dimethyl carbonate as an ambident electrophile
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(Chemical Equation Presented) The features of various anions having different soft/hard character (aliphatic and aromatic amines, alcohoxydes, phenoxides, thiolates) are compared with regard to nucleophilic substitutions on dimethyl carbonate (DMC), using different reaction conditions. Results are well in agreement with the Hard-Soft Acid-Base (HSAB) theory. Accordingly, the high selectivity of monomethylation of CH2 acidic compounds and primary aromatic amines with DMC can be explained by two different subsequent reactions, which are due to the double electrophilic character of DMC. The first step consists of a hard-hard reaction and selectively produces a soft anion, which, in the second phase, selectively transforms into the final monomethylated product, via a soft-soft nucleophilic displacement (yield >99% at complete conversion, using DMC as solvent).
- Tundo, Pietro,Rossi, Laura,Loris, Alessandro
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p. 2219 - 2224
(2007/10/03)
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- Chemoselective deoxygenation of sulfoxides with titanium tetraiodide
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Chemoselective deoxygenation of sulfoxides was carried out using TiI4 as a reducing agent to give sulfides in good to excellent yields.
- Shimizu,Shibuya,Hayakawa
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p. 1437 - 1438
(2007/10/03)
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- Alkylation Reactions by Means of Alkanols and Carbon Monoxide: An Efficient Synthesis of Thioethers and of Caffeine from Theophylline
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The reaction of sodium or potassium thiolates with alkanols and carbon monoxide provides a versatile route to produce thioethers in excellent yields.By analogy, the potassium salt of theophylline suffers a nearly quantitative conversion to caffeine when heated with methanol under CO pressure.The mechanism of these alkylation reactions is discussed. - Key Words: Nucleophilic alkylation / Thioethers / Caffeine / Carbon monoxide / Alkanols
- Bott, Kaspar
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p. 1955 - 1956
(2007/10/02)
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- Esters and Orthoesters as Alkylating Agents at High Temperature. Applications to Continuous-flow Processes
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At high temperature (180-200 deg C) esters, orthoesters, carbonates and orthocarbonates have been found to alkylate acidic compounds via a BAl2 mechanism.Phenol gives anisole with methyl acetate in the presence of potassium carbonate.Thiols and other CH-acidic compounds are also alkylated under such conditions.The results obtained under batch conditions can be repeated under continuous-flow conditions, if the base which promotes the reaction can be used in catalytic amount.Continuous-flow alkylation of thiophenol by methyl acetate on a sodium acetate-type fixedbed, and other alkylations by orthoesters or orthocarbonates on a potassium carbonate catalytic bed, have been achieved.
- Selva, Maurizio,Trotta, Francesco,Tundo, Pietro
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p. 519 - 522
(2007/10/02)
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- Methyl transfers. 14. Nucleophilic catalysis of nucleophilic substitution
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Nucleophiles X- can catalyze the substitution Nu- + RY → NuR + Y- by adding the faster pathway X- + RY → XR + Y- followed by Nu- + XR → RNu + X-. New examples include catalysis by I- of the exchange of methyl between two dialkyl sulfides and the transfer of methyl from an arsonium salt to a phosphine. The individual reactions are separately studied and some equilibrium information is presented. Iodide is ineffective in the transfer of methyl between two pnosphines, which is not detected with or without iodide. The Marcus equation treatment of this catalysis is shown to require that the identity transfer of R between two X- groups be far faster than that for transfer of R between two Nu- groups. Nucleophiles other than I- are discussed. The possibility that some "supernucleophiles" may have fast identity rates is discussed, and literature evidence that this is indeed the case is presented. Stereochemical studies using chiral methyl derivatives have shown that vitamin B12 does provide a nucleophilic catalysis to methyl transfer in living systems. Thus, the apparently superfluous participation of B12 in some biological methyl transfers is explained.
- McCortney,Jacobson,Vreeke,Lewis
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p. 3554 - 3559
(2007/10/02)
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- SYNTHESIS OF SUBSTITUTED TRANS-1,6-DIMETHYLBICYCLONON-2-ENES USING A CLAISEN REARRANGEMENT OF α-(THIOALKOXY)ESTERS
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The Claisen rearrangement of α-(thioalkoxy)esters provided access to substituted trans-1,6-dimethylbicyclonon-2-enes characteristic of the CD rings of the cucurbitanes.
- Richardson, Stewart K.,Sabol, Mark R.,Watt, David S.
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p. 359 - 368
(2007/10/02)
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- New Oxyfunctionalization Capabilities for ω-Hydroxylases: Asymmetric Aliphatic Sulfoxidation and Branched Ether Demethylation
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Due to inherent difficulties in the chemical generation of aliphatic synthons, the stereo- and regioselective oxyfunctionalization of simple aliphatic substrates represents an area where chemical applications of biocatalysis would be particularly useful.The hydrocarbon monooxygenase from Pseudomonas oleovorans is a prototypical "ω-hydroxylase" known to carry out hydroxylation at the terminal methyl of alkanes as well as epoxidation of terminal olefins.It is now demonstrated that this enzyme system catalyzes stereoselective sulfoxidation of methyl thioether substrates, representing the first clear example of oxygenase-produced chiral aliphatic sulfoxides yet reported.In addition, it is shown that this enzyme system catalyzes oxygenative O-demethylation of branched alkyl methyl and branched vinyl methyl ethers to secondary alcohols and ketones, respectively.These findings establish new oxyfunctionalization capabilities, and thus a significantly expanded biotechnological potential, for the hydrocarbon monooxygenases.
- Katopodis, Andreas G.,Smith, Homer A.,May, Sheldon W.
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p. 897 - 899
(2007/10/02)
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- The use of aminoiminomethanesulfinic acid (thiourea dioxide) under phase transfer conditions for generating organochalcogenate anions. Synthesis of sulfides, selenides and tellurides
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A procedure is described which allows for the in situ synthesis of arylalkyl, diaryl and dialkylchalcogenides under phase transfer conditions starting from the corresponding diorganodichalcogenides.The dichalcogenides are reduced by aminoiminomethanesulfinic acid (thiourea dioxide) in alkaline medium and catalyzed by a quaternary ammonium salt.The reduction proceeds easily for diaryl disulfides and diaryl diselenides at a sodium hydroxide concentration of 13percent; diaryl ditellurides require a 50percent sodium hydroxide solution to give the aryl tellurolate anion.The dialkyl diselenides and dialkyl ditellurides are more difficult to reduce.The intermediate arylthiolates and arylselenolates are quenched by alkyl and activated aryl halides to give the corresponding sulfides and selenides in high yield (77-97percent).The aryltellurolates react with alkyl halides giving the aryl alkyl tellurides in 81-96percent yield.The procedure could not be successfully used for the synthesis of dialkylselenides and dialkyl tellurides; low yields and mixture of products were formed.
- Comasseto, J. V.,Lang, E. S.,Ferreira, J. Tercio B.,Simonelli, F.,Correira, V. R.
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p. 329 - 340
(2007/10/02)
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- THIOALKYLTRIBUTYL- AND THIOALKOXYTRIPHENYLPHOSPHONIUM SALTS: PREPARATION AND APPLICATION TO THE SYNTHESIS OF THIOLESTERS AND UNSYMMETRICAL SULFIDES
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Thioalkoxyphosphonium salts, Ph3PSR(1+)*ClO4(1-) (3) and Bu3PSR(1+)*X(1-) (X=ClO4 and BF4) (5), have been prepared from the corresponding tertiary phosphines and disulfides by simple procedures, which involve (i) constant current electrolysis in acetonitrile in the presence of either HClO4 (for 3) or PhCOOH and LiX (for 5), and (ii) stirring an equimolar mixture of a phosphine, a disulfide, PHCOOH, and LiX in acetonitrile at ambient temperature.For the preparation of 3, which have been reported as useful reagents for the synthesis of unsymmetrical disulfides, the electrochemical method is recomended, while for 5 the latter non-electrochemicl procedure gave better results.Reactions of the phosphonium salts 5 with carboxylic acidsand primary alcohols in benzene at ambient temperature gave thiolesters and unsymmetrical sulfides, respectively, in fair to excellent yields.Keywords - triphenylphosphine; tributylphosphine; disulfide; thioalkoxyphosphonium salt; thiolester; unsymmetrical sulfide
- Ohmori, Hidenobu,Maeda, Hatsuo,Konomoto, Kohichi,Sakai, Kiyoshi,Masui, Masaichiro
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p. 4473 - 4481
(2007/10/02)
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- A Facile One-pot Synthesis of Sulfides from Alkyl Halides and Alcohols Using Tetramethylthiourea
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Sulfides can be readily prepared under mild conditions by a reaction of tetramethylthiourea with alkyl halides and alcohols in the presence of sodium hydride in satisfactory yields.The scope and limitation of this method are also presented.
- Fujisaki, Shizuo,Fujiwara, Isamu,Norisue, Yasumasa,Kajigaeshi, Shoji
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p. 2429 - 2430
(2007/10/02)
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- Preparation of thioethers
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Thioethers are prepared by a process wherein an alkali metal mercaptide is reacted with an alcohol and carbon monoxide or with a formate, and are useful starting materials for the preparation of dyes, crop protection agents, drugs and rubber auxiliaries.
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- Process for preparing organic sulphides
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A process for preparing organic thioethers of formula R--S--R1 in which R is an aliphatic, aryl, arylaliphatic or heterocyclic radical and R1 is an aliphatic or arylaliphatic radical, from organic dithiocarbonates and organic halides or sulphonates, in the presence of an aqueous alkaline base and a phase transfer catalyst, at a temperature of between 50° and 100° C. for a time of 10-60 minutes.
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- Desulfuration Using Plasma Techniques, III. - Reaction of Thioethers
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Plasma desulfurations were tested with nine thioethers.While aliphatic, as well as aromatic thioethers and thiophene react easily, benzothiophenes are hard to desulfurize.Predominant reaction products are low molecular alkenes and alkanes (Table 1).Addition of oxygen greatly improves the results (Table 2).
- Suhr, Harald,Henne, Peter,Iacocca, Diodoro,Ropero, Marcos J.
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p. 441 - 446
(2007/10/02)
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