- Development of technique for synthesis of methyl(β-oxyethyl) sulfide by the reaction of ethylene oxide with methyl mercaptan
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Reaction of ethylene oxide with methyl mercaptan in the presence of a catalyst, a solution of potassium hydroxide in methyl(β-oxyethyl) sulfide, was studied. Various technological procedures for synthesis of methyl(β-oxyethyl) sulfide were analyzed. The process conditions providing a 98-99% conversion of the starting reagents at a selectivity of 97-98% were suggested.
- Tuzhikov,Khokhlova,Zotov,Orlova
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- Solvent Influences on Initial and Transition States in Solvolysis of 2-Chloroethyl Methyl Sulfide
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Nucleophilic substitution reactions of 2-(alkylthio)ethyl derivatives have become important in understanding basic principles of physical organic chemistry.In the present work the solvent effects of 2-chloroethyl methyl sulfide (1-Cl) solvolysis in methanol, methanol-water mixtures, and water are analyzed to provide a dissection of initial-state (IS) and transition-state (TS) effects.The reduction in activation energy accompanying replacement of methanol by water is shown to be due to significant IS destabilization and TS stabilization.Further analysis permits dissection of the tree energies of transfer of the TS into electrostatic and nonelectrostatic components.Comparison of the these electrostatic components for 1-Cl and several model substrates shows that charge development in the TS for 1-Cl is approximately 0.6 units of electronic charge.This conclusion is supported by estimation of TS structure from isotope effects, but it is also in apparent conflict with a TS structure deduced from tosylate-chloride rate ratios.An analysis of the tosylate-chloride ratio is presented, and it is proposed that the ratio for 1-Cl is dominated by steric effects at the reactive site, and possibly by IS solvation differences between tosylates and chlorides, rather than by the extent of bond cleavage to the leaving group in the TS.
- Sedaghat-Herati, M. R.,Harris, J. M.,McManus, S. P.
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- Spontaneous formation in the dark, and visible light-induced cleavage, of a Ru-S bond in water: A thermodynamic and kinetic study
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In this work the thermal and photochemical reactivity of a series of ruthenium complexes [Ru(terpy)(N-N)(L)](X)2 (terpy = 2,2′;6′,2″-terpyridine, L = 2-(methylthio)ethanol (Hmte) or water, and X is Cl- or PF6-) with four different bidentate chelates N-N = bpy (2,2′-bipyridine), biq (2,2′-biquinoline), dcbpy (6,6′-dichloro-2,2′-bipyridine), or dmbpy (6,6′-dimethyl-2,2′-bipyridine), is described. For each chelate N-N the thermodynamic constant of the dark equilibrium between the aqua-and Hmte-complexes, the Hmte photosubstitution quantum yield, and the rate constants of the thermal interconversion between the aqua and Hmte complexes were measured at room temperature. By changing the steric hindrance and electronic properties of the spectator N-N ligand along the series bpy, biq, dcbpy, dmbpy the dark reactivity clearly shifts from a nonlabile equilibrium with N-N = bpy to a very labile thermal equilibrium with N-N = dmbpy. According to variable-temperature rate constant measurements in the dark near pH = 7 the activation enthalpies for the thermal substitution of H2O by Hmte are comparable for all ruthenium complexes, whereas the activation entropies are negative for bpy and biq, and positive for dcbpy and dmbpy complexes. These data are indicative of a change in the substitution mechanism, being interchange associative with nonhindered or poorly hindered chelates (bpy, biq), and interchange dissociative for more bulky ligands (dcbpy, dmbpy). For the most labile dmbpy system, the thermal equilibrium is too fast to allow significant modification of the composition of the mixture using light, and for the nonhindered bpy complex the photosubstitution of Hmte by H2O is possible but thermal binding of Hmte to the aqua complex does not occur at room temperature. By contrast, with N-N = biq or dcbpy the thermodynamic and kinetic parameters describing the formation and breakage of the Ru-S bond lie in a range where the bond forms spontaneously in the dark, but is efficiently cleaved under light irradiation. Thus, the ratio between the aqua and Hmte complex in solution can be efficiently controlled at room temperature using visible light irradiation.
- Bahreman, Azadeh,Limburg, Bart,Siegler, Maxime A.,Bouwman, Elisabeth,Bonnet, Sylvestre
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- hydrogen fluorine ether sulphone class compound and its preparation method, the electrolyte of the lithium battery (by machine translation)
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The invention provides a hydrofluoroether sulfones compound and a preparation method thereof as well as lithium-ion battery electrolyte. The lithium-ion battery electrolyte comprises a lithium salt, a solvent and the hydrofluoroether sulfones compound shown as the formula (I). Compared with the prior art, the hydrofluoroether sulfones compound is added into the hydrofluoroether sulfones compound shown as the formula (I) contains a hydrofluoroether radical. Firstly, the hydrofluoroether sulfones compound shown as the formula (I) keeps the high voltage resistance advantage of the sulfones compound and the high voltage resistance of the electrolyte can be improved; the hydrofluoroether radical is good for overcoming the disadvantages of the sulfones compound that the smelting point and the viscosity are high and has high conductivity; then, the hydrofluoroether sulfones compound, an electrolyte common solvent and the lithium salt have good compatibility and a homogeneous solution is easy to form; finally, the hydrofluoroether sulfones compound shown as the formula (I) has the advantages of hydrofluoroether compounds and is good for improving the flashing point of the electrolyte, so that the electrolyte has good fire resistance.
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Paragraph 0069
(2017/03/28)
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- Yellow-light sensitization of a ligand photosubstitution reaction in a ruthenium polypyridyl complex covalently bound to a rhodamine dye
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The ruthenium complex [Ru(terpy)(bpy)(Hmte)]2+ ([1] 2+), where terpy is 2,2′;6′,2′′-terpyridine, bpy is 2,2′-bipyridine, and Hmte is 2-methylthioethan-1-ol, poorly absorbs yellow light, and although its quantum yield for the photosubstitution of Hmte by water is comparable at 570 nm and at 452 nm (0.011(4) vs. 0.016(4) at 298 K at neutral pH), the photoreaction using yellow photons is very slow. Complex [1]2+ was thus functionalized with rhodamine B, an organic dye known for its high extinction coefficient for yellow light. Complex [Ru(Rterpy)(bpy)(Hmte)]3+ ([2]3+) was synthesized, where Rterpy is a terpyridine ligand covalently bound to rhodamine B via a short saturated linker. [2]Cl3 shows a very high extinction coefficient at 570 nm (44000 M-1 cm-1), but its luminescence upon irradiation at 570 nm is completely quenched in aqueous solution. The quantum yield for the photosubstitution of Hmte by water in [2]3+ was comparable to that in [1]2+ at 570 nm (0.0085(6) vs. 0.011(4), respectively), which, in combination with the much better photon collection, resulted in a higher photosubstitution rate constant for [2]3+ than for [1]2+. The energy of yellow photons is thus transferred efficiently from the rhodamine antenna to the ruthenium center, leading to efficient photosubstitution of Hmte. These results bring new opportunities for extending the photoactivation of polypyridyl ruthenium complexes towards longer wavelengths.
- Bahreman, Azadeh,Cuello-Garibo, Jordi-Amat,Bonnet, Sylvestre
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p. 4494 - 4505
(2014/03/21)
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- Chalcogen-containing analogs of ethylene glycol and its derivatives
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Ethylene chlorohydrin when reacted with elemental chalcogens or dimethyl dichalcogenides in the hydrazine hydrate-alkali system forms chalcogen-containing analogs of ethylene glycol and its derivatives (dichalcogenated β-diglycols, chalcogenated ethanols, and chalcogenated methyl cellosolves).
- Vshivtsev,Levanova,Grabel'nykh,Sukhomazova,Albanov,Klyba,Zhanchipova,Russavskaya,Kochervin
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p. 608 - 613
(2008/09/21)
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- Silica-PSCl3: A mild and efficient reagent for deoxygenation of sulfoxides
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A new solid supported reagent, silica-PSCl3, has been developed for deoxygenation of sulfoxides. With this reagent, conversion of sulfoxides to sulfides occurred cleanly and efficiently at room temperature. Facile isolation of the product was achieved by simple filtration of the by-products without any extensive workup. Copyright Taylor & Francis Group, LLC.
- Pandey, Lokesh Kumar,Pathak, Uma,Rao, A. Narasimha
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p. 4105 - 4109
(2008/03/13)
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- Intramolecular sulfur-assisted NaBH4 reduction of esters synthesis of 5-oxo-ETE and 5-oxo-12-HETE
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Ester groups are reduced very efficiently in sulfur-containing molecules situated at close proximity to the ester group. We have used this procedure to regioselectively, efficiently and in high yield reduce an ester group in the presence of another ester group further removed from the sulfur atom. (C) 2000 Elsevier Science Ltd.
- Khanapure, Subhash P.,Saha, Goutam,Sivendran, Sashikala,Powell, William S.,Rokach, Joshua
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p. 5653 - 5657
(2007/10/03)
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- New Synthetic Routes to Unsymmetrical Diorganyl Sulfides
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A number of new methods for preparing unsymmetrical diorganyl sulfides was proposed. The methods rely on generation of thiolate anions from thiols, isothiuronium salts, and disulfides in the system hydrazine hydrate-KOH, followed by alkylation of the anions with alkyl halides. The hydrazine hydrate plays the role of medium and reducing agent, which prevents side thiol oxidation. The yield of sulfides reaches 98%. The reaction products are readily separated from the aqueous-hydrazine layer and purified by distillation. The yield of sulfides is reduced by a deficit of alkali and by increasing chain length and functionalization of alkyl groups in the alkyl halide. The reactivity of alkyl halides is independent of the nature of the halogen. From isothiuronium salts, 2-pyridyl sulfides were obtained in the highest yields.
- Deryagina,Korchevin,Papernaya
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p. 812 - 815
(2007/10/03)
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- EFFICIENT AND/OR SELECTIVE METHYLATION BY DIAZOMETHANE OF ALCOHOLS, HALO ALCOHOLS, GLYCOLS, AMINO ALCOHOLS AND MERCAPTO ALCOHOLS WITH THE USE OF A PROTON-EXCHANGED X-TYPE ZEOLITE AS AN ACID-BASE BIFUNCTIONAL CATALYST
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Reactions of diazomethane with butanol, allyl alcohol and β- and γ-halo alcohols led to efficient methylation (giving the corresponding methyl ethers) with the use of a proton-excahnged X-type zeolite compared with H2SO4.The reactions with propylene and isobutylene glycols using the zeolite provided regioselective methylation of the primary OH rather than the secondary or tertiary OH, whereas regioselectivity was not observed in the reactions using H2SO4.The reactions with 2-aminoethanol and 2-mercaptoethanol showed high chemoselective S-methylation and N-monomethylation, respectively, in the presence of the zeolite instead of H2SO4.The mechanism for the reactions is proposed to involve acid-base bifunctional catalysis of the zeolite in which the acidic site reacts with diazomethane to form its conjugate acid, and the nucleophilicity of OH and SH groups is enhanced by the interaction of the basic site with the proton of the groups.
- Takeuchi, Hiroshi,Kishioka, Hiroaki,Kitajima, Kunio
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p. 121 - 126
(2007/10/02)
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- SN2 Displacement on 2-(Alkylthio)ethyl Derivatives
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We have studied the reaction mechanism of various 2-(alkylthio)ethyl and 2-(arylthio)ethyl derivatives with strong nucleophiles in an attempt to overcome powerful neighboring sulfur participation and shift reaction to a direct displacement SN2 mechanism.The 2,4-dinitrophenolate derivative of specifically deuteriated 2-(methylthio)ethanol reacts by an aromatic substitution mechanism (SNAr) when exposed to amines in aprotoc solvents.Use of sulfonate esters avoids competition from the SNAr mechanism.The rate of reaction of these esters in dimethyl sulfoxide (DMSO) or acetonitrile is independent of concentration of added methylamine, thiourea, urea, or iodide, thus indicating continued SN1 reaction with neighboring sulfur participation.Asd would be expected on this basis, but in contrast to previous mechanistic suggestions, the product for reaction with iodide in acetone shows complete scrambling of methylene groups.In contrast, reaction with thiophenolate ions in DMSO proceeds by direct nucleophilic displacement (an SN2 mechanism), as shown by second-order kinetics and unrearranged product.This is the first demonstration of SN2 displacement on a 2-(alkylthio)ethyl or 2-(arylthio)ethyl derivative.
- Herati-Sedaghat, M. R.,McManus, Samuel P.,Harris, J. Milton
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p. 2539 - 2543
(2007/10/02)
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- The Preparation of 9-Oxo-10-oxaprostanoids by the Conjugate Addition of (E)-1-(Phenylthio)oct-2-enyllithium to γ-Crotonolactone and the Direct Alkylation of the Derived Enolate with Methyl 7-Bromohept-5-ynoate and Related Electrophiles
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The conjugate addition of (E)-1-(phenylthio)oct-2-enyllithium in tetrahydrofuran containing hexamethylphosphoric triamide to γ-crotonolactone (but-2-en-4-olide) followed by treatment of the resulting lactone enolate with either methyl 7-bromohept-5-ynoate or 7-bromohept-5-ynenitrile gave the corresponding enolate trapped products in yields of 50-55percent from the octenyllithium reagent.Use of 7-iodohept-5-ynoate gave a slightly higher yield than the first electrophile.Treatment of the enolate with triphenyltin chloride prior to addition of the electrophiles resulted in approximately 5-10percent enhancement of the yields of the products.The products obtained from the methyl 7-halohept-5-ynoates were converted into the 9-oxo-10-oxaprostanoids through the corresponding sulfoxides and the allylically transposed alcohols by a standard sequence of reactions.In an attempt to convert the lactone ring of the enolate-trapped products into the fully carbocyclic nucleus of primary prostaglandins, the nucleophilic ring opening of the lactone nucleus with the lithiated carbanion derived from t-butyl methyl sulfone in the presence of N,N,N',N'-tetramethylethylenediamine was carried out.However, attempts to oxidize the resulting hemiacetals to the requisite diketone precursors of the carbocyclic prostaglandins were unsuccessful.
- Haynes, Richard K.,Schober, Paul A.
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p. 1249 - 1265
(2007/10/02)
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- Hydrolysis of Mustard Derivatives in Aqueous Acetone-Water and Ethanol-Water Mixtures
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The hydrolyses of two mustard derivatives, 2-chloroethyl ethyl sulfide (CEES) and 2-chloroethyl methyl sulfide (CEMS), were investigated and compared with the hydrolysis of tert-butyl chloride (TBC) in aqueous binary mixtures of acetone and ethanol from 0 to 45 deg C.The solvent effect on rates and on activation parameters provided further evidence for an SN1 mechanism with anchimeric assistance of the sulfur atom to form a cyclic sulfonium ion as the reaction intermediate.Lower ΔH(excit.) and ΔS(excit.) values of both CEES and CEMS relative to that of TBC reflected the S-C bond formation and the strained structure of the intermediate.A finite and negative ΔCp(excit.) was detected.The observed ΔH(excit.) was corrected for the cosolvent effect by adopting Fagley's model and was consistent with the value in pure water.
- Yang, Yu-Chu,Ward, J. Richard,Luteran, Thomas
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p. 2756 - 2759
(2007/10/02)
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- Reaction Mechanism of Cathodic Crossed Coupling of Acetone with Unsaturated Compounds in Acidic Solution
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It was confirmed that the cathodic crossed coupling of acetone with unsaturated compounds in aqueous sulfuric acid could proceed smoothly, when the compounds which had radical-acceptable double bonds and were adsorbed on a mercury cathode were used.From this fact, it was concluded that the coupling occurs via the addition of a radical intermediate formed by the one-electron reduction of acetone to the double bonds on the cathode surface.Possibility of the addition of an anionic intermediate derived from acetone was excluded by no occurrence of the coupling of acetone with a polar acetylenic triple bond compound adsorbed on the cathode.
- Koizumi, Toshio,Fuchigami, Toshio,Kandeel, Zaghloul El-Shahat,Sato, Norio,Nonaka, Tsutomu
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p. 757 - 762
(2007/10/02)
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- Effects of Volume and Surface Property in Hydrolysis by Acetylcholinesterase. The Trimethyl Site
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β-Substituted ethyl acetates, XCH2CH2OCOCH3, have been prepared, and their hydrolysis by acetylcholinesterase has been studied.Log of enzymic reactivity, normalized for intrinsic reactivity in hydrolysis by hydroxide, log(kcat/Km)n, rises linearly with increasing refraction volume, MR (or RD25), for substrates with β-X = H, Cl, Br, CH3CH2, (CH3)2CH, (CH3)2S+, (CH3)3N+, and (CH3)3C.Larger substituents may by accommodated, (CH3)3Si and (CH3CH2)3N+, with no further increase in rate.Substrates with β-substituents CH3S, CH3S(O), (CH3)3N+(OH), and CH3S(O2) are less reactive than consistent with the relation with MR by factors of 5-40, indicating that hydrophobic surface and desolvation of the substrate-enzyme interface may be necessary for maximum reactivity correlated with MR.Values of log (kcat/Km)n for substrates with β-substituents X = CH3S, Cl, Br, CH3CH2, (CH3)2CH, (CH3)3C, and (CH3)3Si rise linearly with increasing hydrophobicity, ?, but reactivity of substrates with X = (CH3)3N+ and (CH3)2S+ are more reactive than consistent with a relation to ? by factors of 300 and 40 and with X = CH3S(O2), CH3S(O), and (CH3)2N+(OH), by factors of 7-100.Reactivity appears related to (i) volume of the β-substituent and its fit in its subsite, which is trimethyl rather than anionic, and (ii) the hydrophobicity of its surface.
- Cohen, Saul G.,Elkind, Jerome L.,Chishti, S. Bano,Giner, Jose-L. P.,Reese, Heide,Cohen, Jonathan B.
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p. 1643 - 1647
(2007/10/02)
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- A CONVENIENT MATHOD FOR PREPARATION OF 1-(METHYLTHIO) AND 1-(PHENYLTHIO)VINYLLITHIUM REAGENTS
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1-(Methylthio) and 1-(phenylthio)vinyllithiums were prepared by the treatment of the corresponding 2-methoxyethyl sulfides with twice molar amounts of butyllithium in the presence of N,N,N',N'-tetramethylethylenediamine (TMEDA). β-Alkylthio-β,γ-unsaturated alcohols were obtained in good yields by the reaction of the lithium salts with aldehydes.
- Takeda, Takeshi,Furukawa, Hiroyuki,Fujiwara, Tooru
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p. 593 - 596
(2007/10/02)
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- Cyclopropane esters
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Esters of cyclopropyl substituted carboxylic acids, syntheses thereof, compositions thereof, and use for the control of mites and ticks.
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