- Palladium catalyzed synthesis of aryl thiols: Sodium thiosulfate as a cheap and nontoxic mercapto surrogate
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A Pd-catalyzed coupling reaction of ArBr/ArCl/ArOTf with sodium thiosulfate takes place in presence of Cs2CO3 at 80 °C. The reaction mixture is directly treated with Zn/HCl to afford aryl thiols in good to excellent yields.
- Yi, Jun,Fu, Yao,Xiao, Bin,Cui, Wei-Chen,Guo, Qing-Xiang
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experimental part
p. 205 - 208
(2011/02/26)
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- Copper-catalyzed coupling of thiourea with aryl iodides: The direct synthesis of aryl thiols
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A general, economical and efficient protocol for the direct copper-catalyzed coupling of thiourea with aryl iodides is developed and it will be potentially applied in large-scale industry as a preferred process.
- Qiao, Shu,Xie, Kun,Qi, Junsheng
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scheme or table
p. 1441 - 1443
(2011/01/04)
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- Thermal reactions of chloroarenes with hydrogen sulfide in the presence of methanol
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Gas-phase reactions of chloroarenes (ClC6H4X, X = H, 4-CH3, 4-OH, 4-Cl, 4-CF3) with hydrogen sulfide or its precursors were investigated in the presence of methanol, which was a stronger H-donor than hydrogen sulfide. Introducing methanol increased the selectivity of arenethiols formation at X = H and 4-CH3 and did not affect the reaction selectivity at acceptor X. The efficiency of methanol influence was considered from the viewpoint of free-radical reaction mechanism and the stability of the arenethiyl radicals. 2005 Pleiades Publishing, Inc.
- Deryagina,Sukhomasova,Levanova,Papernaya,Korchevin
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p. 1624 - 1630
(2007/10/03)
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- Direct synthesis of thioethers from sulfonyl chlorides and activated alcohols
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An efficient, safe one-pot synthesis of thioethers from aromatic sulfonyl chlorides and activated alcohols has been developed under non-aqueous conditions.
- Martin, Michael T,Thomas, Alford M,York, Douglas G
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p. 2145 - 2147
(2007/10/03)
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- ELECTROLYTE MATERIALS CONTAINING HIGHLY DISSOCIATED METAL ION SALTS
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The present invention relates to metal ion salts which can be used in electrolytes for producing electrochemical devices, including both primary and secondary batteries, photoelectrochemical cells and electrochromic displays. The salts have a low energy o
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- Molecular recognition in aqueous media. new binding studies provide further insights into the cation-π interaction and related phenomena
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We describe a large number of binding studies in aqueous media designed to provide new insights into noncovalent binding interactions, especially the cation-π interaction. The studies include 7 different hosts, over 70 guests, and over 150 new binding constants. In addition to the now standard NMR methods, circular dichroism has proven to be an especially useful tool for determining aqueous binding constants. We have found that, in addition to the alkyliminium and tetraalkylammonium guests we have studied previously, sulfonium and guanidinium guests also show substantial cation-π effects. Bromination of the host greatly enhances its binding ability in a general fashion, primarily as a result of hydrophobic interactions. Addition of methoxy groups did not enhance binding, apparently as a result of a collapse of the host into a conformation that is not suitable for binding. Replacement of two benzene rings of the host by furans or thiophenes also did not enhance binding. Ab initio calculations provide a rationalization for this effect and suggest a clearer model for the cation-π interaction.
- Kearney, Patrick C.,Mizoue, Laura S.,Kumpf, Robert A.,Forman, Jonathan E.,McCurdy, Alison,Dougherty, Dennis A.
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p. 9907 - 9919
(2007/10/02)
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- β-D-phenylthioxylosides, their method of preparation and their use as therapeutic agents
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The present invention relates, by way of novel industrial products, to the β-D-phenylthioxyloside compounds of the formula STR1 in which: X represents a sulfur atom or an oxygen atom; R1, R2 and R3, which are identical or different, each represent a hydrogen atom, a nitro group, a cyano group, a group --CO--R (in which R represents a C1 -C4 alkyl group or a trifluoromethyl group), an amino group, an acetamido group (NHCOCH3), a C1 -C4 alkoxy group, a trifluoromethyl group or a phenyl group substituted by one or more cyano, nitro or trifluoromethyl groups, it being possible for R1 and R2, taken together, to form, with the phenyl group to which they are bonded, a β-naphthalenyl group which is unsubstituted or substituted by one or more cyano, nitro or trifluoromethyl groups; and Y represents the hydrogen atom or an aliphatic acyl group. These compounds are useful as therapeutic agents, especially as venous antithrombotics.
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- HIGH-TEMPERATURE ORGANIC SYNTHESIS. XXVII. REACTIONS OF ALKANETHIONES WITH THE CHLORINE DERIVATIVES OF BENZENE, THIOPHENE, AND NAPHTHALENE
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Alkanethiols react effectively with chlorobenzene, its derivatives, 1-chloronaphthalene, and 2-chlorothiophene at 600-660 deg C with the preferential formation of the corresponding aromatic or heteroatomic thiols.Ethanethiol is most reactive.When it is used instead of hydrogen sulfide in reactions with chlorobenzene or its 4-substituted derivatives, the yield of the aromatic thiols, from which the phenylthiyl radicals are generated with greater difficulty, increases more sharply than the yield of the thiophenols, which generate the more stable 4-XC6H4S radicals.The side products of the reactions are the corresponding diaryl sulfides, thiophene, benzothiophene, and toluene.
- Voronkov, M. G.,Deryagina, E. N.,Sukhomazova, E. N.
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p. 755 - 760
(2007/10/02)
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- Thioether complexes of tungsten hexacarbonyl
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The preparation of a series of organic and organometallic thioethers R3MSR' (M = C,Si,Ge, or Sn) is reported.From these, several new compounds of type 1 are synthesized, some of which contain para-substituted aryl functions for R and R'.In hexane solution in the carbonyl streching region of the ir the uv there is evidence for a degree of multiple bonding, at least in the M - S - WW - CO portion of these molecules.Multiple bonding extending into aromatic R or R'is small or non-existent and cannot be assessed precisely because of spontaneous decomposition of the complexes.All the complexes undergo a thermally initiated decomposition, the case of which depends on the nature of R, R', and M.The unusual W(I) thiolate cis-2 is the termal decomposition product.
- Lucas, C. Robert
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p. 1758 - 1763
(2007/10/02)
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- RESONANCE RAMAN SPECTRA OF RUBREDOXIN, DESULFOREDOXIN, AND THE SYNTHETIC ANALOGUE Fe(S2-o-xyl)2 - : CONFORMATIONAL EFFECTS.
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The resonance Raman (RR) spectrum of the rubredoxin analogue Fe(S//2-o-xyl)//2** minus (S//2-o-xyl equals o-xylylene- alpha , alpha prime -dithiolate) shows four widely spaced bands (I-IV) in the Fe-S stretching region, 297, 321, 350, and 374 cm** minus *
- Yachandra,Hare,Moura,Spiro
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p. 6455 - 6461
(2007/10/02)
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- HIGH TEMPERATURE ORGANIC SYNTHESIS. XIX. MECHANISM OF HIGH-TEMPERATURE REACTION OF AROMATIC CHLORINE DERIVATIVES WITH HYDROGEN SULFIDE
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Quantum-chemical calculations were made in the CNDO/2 approximation for para-substituted chlorobenzene and thiophenol, and the x-ray fluorescence Kα and Kβ spectra of the sulfur in the latter were obtained.The electronic structure parameters of these compounds were compared with their reactivity in high-temperature processess.The reactivity of 4-substituted chlorobenzenes in reaction with hydrogen sulfide in the gas phase correlates with the electron density at the chlorine atom of the chlorine derivative.The direction of this process (the formationof the corresponding thiophenol or diaryl sulfide) is determined by the ability of the thiophenol formed at the first stage to generate sufficiently stable phenylthiyl radicals.The latter are stabilized by a mechanism of ?-conjugation, and the stability increases with increase in the ?-donating character of the para substituent in the aromatic ring. ?-Accepting substituents destabilize the phenylthiyl radicals, increasing the selectivity of the process leading to the production of the respective thiophenol.
- Voronkov, M. G.,Deryagina, E. N.,Dolenko, G. N.,Ivanova, G. M.,Sukhomazova, E. N.,et. al.
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p. 2095 - 2101
(2007/10/02)
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- HIGH-TEMPERATURE ORGANIC SYNTHESIS. XVII. REACTION OF CHLOROBENZENE AND ITS DERIVATIVES WITH DIALKYL DISULFIDES
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The products from the reaction of chlorobenzene with dialkyl disulfides in the gas phase at 550-650 deg C are benzene, thiophenol, diphenyl sulfide, and also toluene, thiophene, and benzothiophene.Diethyl disulfide is most reactive.Its copyrolysis with chlorobenzene is distinguished by high selectivity for the formation of thiophenol, the yield of which amounts to 60percent.In the reaction of substituted chlorobenzenes and also 2-chlorothiophene and 1-chloronaphthalene with diethyl disulfide the corresponding thiols were obtained with high yields.Two paths for the formation of thiophene during the pyrolysis of dialkyl disulfide were established, i.e., from vinyl hydrosulfide and S-butyl radical.The last reaction is realized at a high rate.
- Voronkov, M. G.,Deryagina, E. N.,Sukhomazova, E. N.
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p. 1516 - 1522
(2007/10/02)
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- Electrophilic additions to allenes. VI. The role of steric versus electronic effects in the reactions of arenesulphenyl halides with allenes
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The role of steric and electronic effects during the rate and product determining steps for the addition of arenesulphenyl chlorides to 1,3-disubstituted allenes has been briefly examined.Both effects appear to be generally of minimal importance during the rate determinig step.The available rate data indicate the presence of little, if any, build up of positive charge on sulphur.These results are interpreted in terms of an SN2 attack on bivalent sulphur leading to an alkylidenethiiranium ion intermediate.Steric effects are of greater importance in the product determinig step, particularly when the sulphenyl chlorides possess two bulky ortho substituents, as in the case of 2,4,6-triisopropylbenzenesulphenyl chloride.
- Garratt, Dennis G.,Beaulieu, Pierre L.
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p. 2738 - 2744
(2007/10/02)
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