- TRANSFORMATIONS OF 2-METHYLTHIACYCLOBUTANE IN THE PRESENCE OF ALUMINUM OXIDE
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The transformations of 2-methylthiacyclobutane at 150-350 deg C in the presence of γ-Al2O3 samples with different aprotic acidities were investigated.It was established that the sulfide undergoes isomerization via two pathways, viz., with ring expansion to a five-membered ring and with opening at one C-S bond to give an unsaturated thiol.An experimental confirmation of the consecutive formation of hydrogen sulfide from a one-ring sulfide through a step involving the formation of an unsaturated thiol was obtained for the first time.The transformations are realized asa result of both ionic and polymerization-depolymerization processes.
- Yuskovich, A. K.,Danilova, T. A.,Viktorova, E. A.
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Read Online
- Standard enthalpies of formation of Li, Na, K, and Cs thiolates
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The standard enthalpies of formation of alkaline metals thiolates in the crystalline state were determined by reaction-solution calorimetry. The obtained results at 298.15 K were as follows: δfH°m(MSR, cr)/kJ mol-1 = -259.0 ± 1.6 (LiSC2H5), -199.9 ± 1.8 (NaSC2H5), -254.9 ± 2.4 (NaSC4H9), -240.6 ± 1.9 (KSC2H 5), -235.8 ± 2.0 (CsSC2H5). These results where compared with the literature values for the corresponding alkoxides and together with values for δfH° m(MSR, cr) were used to derive a consistent set of lattice energies for MSR compounds based on the Kapustinskii equation. This allows the estimation of the enthalpy of formation for some non-measured thiolates.
- Leal, Joao P.
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Read Online
- Photoactivatable Odorants for Chemosensory Research
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The chemosensory system of any animal relies on a vast array of detectors tuned to distinct chemical cues. Odorant receptors and the ion channels of the TRP family are all uniquely expressed in olfactory tissues in a species-specific manner. Great effort has been made to characterize the molecular and pharmacological properties of these proteins. Nevertheless, most of the natural ligands are highly hydrophobic molecules that are not amenable to controlled delivery. We sought to develop photoreleasable, biologically inactive odorants that could be delivered to the target receptor or ion channel and effectively activated by a short light pulse. Chemically distinct ligands eugenol, benzaldehyde, 2-phenethylamine, ethanethiol, butane-1-thiol, and 2,2-dimethylethane-1-thiol were modified by covalently attaching the photoremovable protecting group (8-cyano-7-hydroxyquinolin-2-yl)methyl (CyHQ). The CyHQ derivatives were shown to release the active odorant upon illumination with 365 and 405 nm light. We characterized their bioactivity by measuring activation of recombinant TRPV1 and TRPA1 ion channels expressed in HEK 293 cells and the electroolfactogram (EOG) response from intact mouse olfactory epithelium (OE). Illumination with 405 nm light was sufficient to robustly activate TRP channels within milliseconds of the light pulse. Photoactivation of channels was superior to activation by conventional bath application of the ligands. Photolysis of the CyHQ-protected odorants efficiently activated an EOG response in a dose-dependent manner with kinetics similar to that evoked by the vaporized odorant amyl acetate (AAc). We conclude that CyHQ-based, photoreleasable odorants can be successfully implemented in chemosensory research.
- Gore, Sangram,Ukhanov, Kirill,Herbivo, Cyril,Asad, Naeem,Bobkov, Yuriy V.,Martens, Jeffrey R.,Dore, Timothy M.
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p. 2516 - 2528
(2020/10/02)
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- COPPER PROTECTIVE AGENT
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A copper protective agent is provided. The copper protective agent is represented by a general formula (GI): HS—R (GI); and R is a linear or branched alkyl group having 1 to 20 carbon atoms.
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Paragraph 0033-0034
(2019/05/24)
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- Hydropersulfides: H-Atom Transfer Agents Par Excellence
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Hydropersulfides (RSSH) are formed endogenously via the reaction of the gaseous biotransmitter hydrogen sulfide (H2S) and disulfides (RSSR) and/or sulfenic acids (RSOH). RSSH have been investigated for their ability to store H2S in vivo and as a line of defense against oxidative stress, from which it is clear that RSSH are much more reactive to two-electron oxidants than thiols. Herein we describe the results of our investigations into the H-atom transfer chemistry of RSSH, contrasting it with the well-known H-atom transfer chemistry of thiols. In fact, RSSH are excellent H-atom donors to alkyl (k ~ 5 × 108 M-1 s-1), alkoxyl (k ~ 1 × 109 M-1 s-1), peroxyl (k ~ 2 × 106 M-1 s-1), and thiyl (k > 1 × 1010 M-1 s-1) radicals, besting thiols by as little as 1 order and as much as 4 orders of magnitude. The inherently high reactivity of RSSH to H-atom transfer is based largely on thermodynamic factors; the weak RSS-H bond dissociation enthalpy (~70 kcal/mol) and the associated high stability of the perthiyl radical make the foregoing reactions exothermic by 15-34 kcal/mol. Of particular relevance in the context of oxidative stress is the reactivity of RSSH to peroxyl radicals, where favorable thermodynamics are bolstered by a secondary orbital interaction in the transition state of the formal H-atom transfer that drives the inherent reactivity of RSSH to match that of α-tocopherol (α-TOH), nature's premier radical-trapping antioxidant. Significantly, the reactivity of RSSH eclipses that of α-TOH in H-bond-accepting media because of their low H-bond acidity (α2H ~ 0.1). This affords RSSH a unique versatility compared to other highly reactive radical-trapping antioxidants (e.g., phenols, diarylamines, hydroxylamines, sulfenic acids), which tend to have high H-bond acidities. Moreover, the perthiyl radicals that result are highly persistent under autoxidation conditions and undergo very rapid dimerization (k = 5 × 109 M-1 s-1) in lieu of reacting with O2 or autoxidizable substrates.
- Chauvin, Jean-Philippe R.,Griesser, Markus,Pratt, Derek A.
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supporting information
p. 6484 - 6493
(2017/09/12)
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- Phosphorus Pentasulfide Mediated Conversion of Primary Carbamates into Thiols
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In this paper, we report a method for the conversion of primary carbamates into thiols in the presence of phosphorus pentasulfide (P 2 S 5) in refluxing toluene. Presently, no method exists in the literature for conversion of carbamates into thiols and, to the best of our knowledge, it is the first report for this type of conversion. This method presents an indirect route for the conversion of alcohols into thiols via their carbamate derivatives that may be useful in the total synthesis of compounds containing a thiol functionality.
- Maurya, Chandra Kant,Gupta, Pradeep Kumar
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p. 1649 - 1651
(2017/08/11)
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- Insight into the Mechanism of Reversible Ring-Opening of 1,3-Benzoxazine with Thiols
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The reversible ring-opening addition and fragmentation reaction of p-cresol-based N-phenylbenzoxazine with aliphatic and aromatic thiols was investigated in solvent-mediated and solvent-free reactions. Independently of the used thiol, N-phenylbenzoxazine and the thiols reacted to equilibrium with comparable amounts of reactants and products in aprotic solvent, whereas in protic solvent almost full conversions were reached. In contrast, thiol reactivity was a crucial factor in solvent-free reactions yielding fast and complete conversions for a more acidic thiol and balanced equilibrium concentrations in case of thiols with high pKa values. The strong influence of thiols with low pKa values emphasizes the relevance of the protonation step in the ring-opening reactions of 1,3-benzoxazines with thiols in absence of solvents where acidity predominates nucleophilicity. The reverse reactions, namely adduct dissociation and benzoxazine recovery, were successfully conducted at elevated temperatures and reduced pressure facilitated by the removal of the formed thiols yielding up to 95% recovered 1,3-benzoxazine. These results provide deeper understanding of the reversible ring-opening reaction mechanism of 1,3-benzoxazine with thiols.
- Urbaniak, Tobias,Soto, Marc,Liebeke, Manuel,Koschek, Katharina
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p. 4050 - 4055
(2017/04/27)
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- Two-step three-component process for one-pot synthesis of 8-alkylmercaptocaffeine derivatives
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A highly efficient, odourless and two-step three-component process for one-pot synthesis of some 8-alkylmercaptocaffeine derivatives has been described. The catalyst-free three-component reaction of alkyl bromides, thiourea, and 8-bromocaffeine gave 8-alkylmercaptocaffeine products in excellent to quantitative yields. In addition, the impact of parameters on sample reaction is discussed.
- Rad, M. N. Soltani,Maghsoudi
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p. 70335 - 70342
(2016/08/06)
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- Interrogation of the Substrate Profile and Catalytic Properties of the Phosphotriesterase from Sphingobium sp. Strain TCM1: An Enzyme Capable of Hydrolyzing Organophosphate Flame Retardants and Plasticizers
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The most familiar organophosphorus compounds are the neurotoxic insecticides and nerve agents. A related group of organophosphorus compounds, the phosphotriester plasticizers and flame retardants, has recently become widely used. Unlike the neurotoxic phosphotriesters, the plasticizers and flame retardants lack an easily hydrolyzable bond. While the hydrolysis of the neurotoxic organophosphates by phosphotriesterase enzymes is well-known, the lack of a labile bond in the flame retardants and plasticizers renders them inert to typical phosphotriesterases. A phosphotriesterase from Sphingobium sp. strain TCM1 (Sb-PTE) has recently been reported to catalyze the hydrolysis of organophosphorus flame retardants. This enzyme has now been expressed in Escherichia coli, and the activity with a wide variety of organophosphorus substrates has been characterized and compared to the activity of the well-known phosphotriesterase from Pseudomonas diminuta (Pd-PTE). Structure prediction suggests that Sb-PTE has a β-propeller fold, and homology modeling has identified a potential mononuclear manganese binding site. Sb-PTE exhibits catalytic activity against typical phosphotriesterase substrates such as paraoxon, but unlike Pd-PTE, Sb-PTE is also able to effectively hydrolyze flame retardants, plasticizers, and industrial solvents. Sb-PTE can hydrolyze both phosphorus-oxygen bonds and phosphorus-sulfur bonds, but not phosphorus-nitrogen bonds. The best substrate for Sb-PTE is the flame retardant triphenyl phosphate with a kcat/Km of 1.7 × 106 M-1 s-1. Quite remarkably, Sb-PTE is also able to hydrolyze phosphotriesters with simple alcohol leaving groups such as tributyl phosphate (kcat/Km = 40 M-1 s-1), suggesting that this enzyme could be useful for the bioremediation of a wide variety of organophosphorus compounds.
- Xiang, Dao Feng,Bigley, Andrew N.,Ren, Zhongjie,Xue, Haoran,Hull, Kenneth G.,Romo, Daniel,Raushel, Frank M.
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p. 7539 - 7549
(2016/01/09)
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- The Ever-surprising chemistry of boron: Enhanced acidity of phosphine·boranes
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The gas-phase acidity of a series of phosphines and their corresponding phosphine·borane derivatives was measured by FT-ICR techniques. BH 3 attachment leads to a substantial increase of the intrinsic acidity of the system (from 80 to 110 kJ mol-1). This acidity-enhancing effect of BH3 is enormous, between 13 and 18 orders of magnitude in terms of ionization constants. This indicates that the enhancement of the acidity of protic acids by Lewis acids usually observed in solution also occurs in the gas phase. High- level DFT calculations reveal that this acidity enhancement is essentially due to stronger stabilization of the anion with respect to the neutral species on BH3 association, due to a stronger electron donor ability of P in the anion and better dispersion of the negative charge in the system when the BH3 group is present. Our study also shows that deprotonation of ClCH2PH2 and ClCH 2PH2·BH3 is followed by chloride departure. For the latter compound deprotonation at the BH3 group is found to be more favorable than PH2 deprotonation, and the subsequent loss of Cl- is kinetically favored with respect to loss of Cl - in a typical SN2 process. Hence, ClCH2PH 2·BH3 is the only phosphine·borane adduct included in this study which behaves as a boron acid rather than as a phosphorus acid.
- Hurtado, Marcela,Yanez, Manuel,Herrero, Rebeca,Guerrero, Andres,Juan Z. Davalos,Jose-Luis, M. Abboud,Khater, Brahim,Guillemin, Jean-Claude
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supporting information; experimental part
p. 4622 - 4629
(2009/12/29)
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- In situ generation of n-butanethiol and its reaction with electron-deficient olefines
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n-Butanethiol is generated in situ by sequential addition of n-butyllithium and water to elemental sulfur. The n-butanethiol formed was reacted with electron-deficient olefines to give Michael-type addition products in good yields. The method avoids the manipulation of the bad-smelling n-butanethiol. Copyright Taylor & Francis Group, LLC.
- Gariani, Rogerio A.,Santos, Alcindo A. Dos,Comasseto, Joao V.
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p. 789 - 795
(2008/09/16)
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- Process and catalyst for synthesis of mercaptans and sulfides from alcohols
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A process and catalyst blend for selectively producing mercaptans and sulfides from alcohols. The alcohol is reacted with hydrogen sulfide, in the presence of a catalyst blend containing a hydrotreating catalyst and a dehydration catalyst to convert the alcohol to mercaptan or sulfide in one-pass. The alcohols can include primary and secondary alcohols. The mercaptan or sulfide having less than about 30% unreacted alcohol contained therein.
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Page/Page column 8-9
(2008/06/13)
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- An improved and green preparation of 3-(alkylthio)propionic acids
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An efficient, facile microwave-assisted synthesis has been developed for the preparation of unsymmetrical sulfide derivatives from 3-mercaptopropionic acid and a wide variety of alkyl, allyl or aryl chlorides or bromides. The synthesis performed in ethanol at 80 or 120 °C using sodium hydroxide as a base, selectively without an offensive smell, generates 3-(alkylthio)propionic acids in good yields. Effects of reaction components, temperature, and the heating technique on the formation of the product and side-products were studied.
- Vaismaa, Matti J. P.,Yliniemel?, Sanna M.,Lajunen, Marja K.
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p. 1317 - 1323
(2008/10/09)
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- Trifluoromethylthiolation of 1,3-dithiane
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With a view to synthesize 2-(trifluoromethylthio)-1,3-dithiane (1), 1,3-dithiane (2) was reacted in dry pentane at -78°C under dry N2 with trifluoromethylsulfenyl chloride (3) and was found to furnish the desired compound in poor yields along with ten other compounds. Under similar conditions, 2-lithio-1,3-dithiane on treatment with 2 and bis-(trifluoromethyl) disulfide (4) gave 8.0% and 10.0% yields of 1, respectively. In connection with this study, (cholromethyl) propyl sulfide and bis(propylthio)methane were synthesized. The reaction of the latter with 3 was also investigated. The characterization of the primary compound formed in the reaction of 2 with 3 using the 'INAPT'-NMR and GC-MS, the probable mechanism of the formation of the various compounds and their mass spectral identification are presented in this article. Copyright Taylor & Francis Group, LLC.
- Munavalli,Rohrbaugh,Szafraniec,Durst
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p. 305 - 324
(2008/02/04)
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- Synthesis and antifungal activities of alkyl N-(1,2,3-thiadiazole-4-carbonyl) carbamates and S-alkyl N-(1,2,3-thiadiazole-4-carbonyl) carbamothioates
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A series of alkyl N-(1,2,3-thiadiazole-4-carbonyl) carbamates and S-alkyl N-(1,2,3-thiadiazole-4-carbonyl) carbamothioates with unsubstituted or monobrominated straight chain alkyl groups were synthesized and evaluated as fungistatic agents against Gibberella zeae and Altemaria kikuchiana. These compounds showed variable antifungal activities at concentrations of 5 and 50 μg/mL The results showed that antifungal activities depended on the length of the alkyl chain with the optimal chain length of 6-11 carbons. Carbamic acid, (1,2,3-thiadiazole-4-ylcarbonyl)-, hexyl ester (4) showed a strong fungistatic activity against A. kikuchiana at both concentrations, with 90.7 and 54% growth inhibition at 50 and 5 μg/mL, respectively. Carbamic acid, (1,2,3-thiadiazole-4-ylcarbonyl)-, heptyl ester (5); Carbamic acid, (1,2,3-thiadiazole-4-ylcarbonyl)-, octyl ester (6); and Carbamic acid, (1,2,3-thiadiazole-4-ylcarbonyl)-, undecyl ester (9) showed strong fungistatic activity against G. zeae at both concentrations. Their growth inhibitions against G. zeae at the concentration of 5 μg/mL were 78, 63, and 59%, respectively.
- Li, Zaifeng,Wu, Zengru,Luo, Fuying
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p. 3872 - 3876
(2007/10/03)
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- Catalytic synthesis of thiols from alcohols and hydrogen sulfide
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The basic features of the reaction of thiol synthesis from hydrogen sulfide and methanol, n-propanol, n-butanol, or n-dodecanol in the presence of acid-base catalysts was studied. The catalysts with paired surface sites-weak Lewis acid sites and strong base sites-have a low activity but are selective in thiol formation. The catalysts with strong acid sites exhibited a high activity in the conversion of alcohols but were not selective in the formation of thiols. In the presence of proton-donor catalysts, the thiolation of methanol alone took place; other alcohols underwent only dehydration. The thiolation of methanol on various catalysts yielded dimethyl sulfide along with metanethiol; no dialkyl sulfides was produced in the reaction of hydrogen sulfide with higher alcohols. Copyright
- Mashkina
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- Reductions using LiCl/NaBH4: A rapid and efficient cleavage of organic disulfides to mercaptans
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A practical and novel reagent system LiCl/NaBH4 is used for the reductive cleavage of organic disulfides to mercaptans under mild conditions, in excellent yields.
- Rajaram,Purushothama Chary,Iyengar
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p. 622 - 624
(2007/10/03)
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- A new approach to reductive deprotection of thioethers with a low-valent titanium reagent
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Low-valent titanium mediated cleavage of carbon-sulphur bond is reported. This has resulted in an efficient and mild protocol for the deprotection of allyl/benzyl thioethers under reductive condition and with good yields. Deprotection can be performed regio- and chemo-selectively in the presence of acid, ester and N-benzyl/allyl functionalities and is general for aliphatic and aromatic precursors.
- Shadakshari,Talukdar,Chattopadhyay
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p. 1007 - 1010
(2007/10/03)
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- A preparative scale reduction of alkyl disulfides with tributyl phosphine and water
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A series of alkyl disulfides has been shown to be reduced by tributyl phosphine at room temperature. The resulting thiols were then acylated in the same pot and isolated in good yields. This sequence is convenient and is a practical option for the preparation of gram quantities of thiol or thioester from the corresponding disulfide.
- Ayers, Joshua T.,Anderson, Shelby R.
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p. 351 - 358
(2007/10/03)
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- Acid-catalyzed breakdown of alkoxide and thiolate ion adducts of benzylidene Meldrum's acid, methoxybenzylidene Meldrum's acid and thiomethoxybenzylidene Meldrum's acid
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A kinetic study of the acid-catalyzed loss of alkoxide and thiolate ions from alkoxide and thiolate ion adducts, respectively, of benzylidene Meldrum's acid (1-H), methoxybenzylidene Meldrum's acid (1-OMe), and thiomethoxybenzylidene Meldrum's acid (1-SMe) is reported. The reactions appear to be subject to general acid catalysis, although the catalytic effect of buffers is weak and the bulk of the reported data refers to H+-catalysis. α-Carbon protonation and, in some cases, protonation of one of the carbonyl oxygens to form an enol compete with alkoxide or thiolate ion expulsion. This rendered the kinetic analysis more complex but allowed the determination of pK(a) values and of proton-transfer rate constants at the α-carbon. In conjunction with previously reported data on the nucleophilic addition of alkoxide and thiolate ions to the same Meldrum's acid derivatives, rate constants for nucleophilic addition by the respective neutral alcohols and thiols could also be calculated. Various structure-reactivity relationships are discussed that help define transition-state structures. Comparisons with similar reactions of alkoxide ion adducts of β-alkoxy-α-nitrostilbenes provide additional insights.
- Bernasconi, Claude F.,Ketner, Rodney J.,Brown, Shoshana D.,Chen, Xin,Rappoport, Zvi
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p. 8829 - 8839
(2007/10/03)
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- Solid Supported Reagents and Reactions. Part 21.1 Rapid and Clean Synthesis of Thiols from Halides Using Polymer-supported Hydrosulfide
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A variety of thiols are prepared from corresponding halides using polymer-supported hydrosulfide in excellent yields. Isolation of pure products by simple filtration and evaporation is an important feature of this method.
- Bandgar, Babasaheb P.,Pawar, Sanjay B.
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p. 212 - 213
(2007/10/03)
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- Kinetics of the reactions of methoxybenzylidene Meldrum's acid with thiolate ions, alkoxide ions, OH-, and water in aqueous DMSO. Detection and kinetic characterization of the S(N)V intermediate
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The nucleophilic vinylic substitution (S(N)V) reactions of methoxybenzylidene Meldrum's acid (5-OMe) follow the common two-step mechanism involving a tetrahedral intermediate. With thiolate and alkoxide ions, this intermediate is shown to accumulate to detectable levels and a detailed kinetic study allowed the determination of the rate constants of the various elementary steps. With OH- as the nucleophile, the intermediate cannot be observed; it is shown that this is the result of the intermediate rapidly breaking down to products by a pathway not available in the reactions with the thiolate or alkoxide ions. Comparison of structure-reactivity data for the reactions of 5-OMe with those of benzylidene Meldrum's acid (5-H) and β-methoxy-α-nitrostilbene (4-OMe) reveal a complex interplay of steric effects, π-donor and π-acceptor resonance effects, and anomeric effects.
- Bernasconi, Claude F.,Ketner, Rodney J.,Chen, Xin,Rappoport, Zvi
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p. 7461 - 7468
(2007/10/03)
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- Chemical implications for antitumor and antiviral prostaglandins: Reaction of Δ7-prostaglandin A1 and prostaglandin A1 methyl esters with thiols
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Prostaglandins (PGs) such as Δ12-PGJ2 and Δ7-PGA1 methyl ester that possess a cross-conjugated dienone unit exhibit unique antitumor and antiviral activities independent of intracellular cAMP levels. These compounds are transported reversibly into cultured cells and accumulate in nuclei via covalent interaction, eliciting growth inhibition. PGA1 methyl ester, a simple cyclopentenone analog, is less potent. The unique cellular behavior of the dienone PGs correlates well with their chemical properties. The PGs react specifically with thiol nucleophiles such as glutathione. Michael addition of thiols to Δ7-PGA1 methyl ester, an alkylidenecyclopentenone derivative, occurs facilely at the endocyclic C(11) position rather than at the C(7) position. This process is reversible, and in solution phase, the adducts are in equilibrium with considerable amounts of free PG and thiols. However, the reaction of this PG with Sepharose-bound thiols, regarded to be plausible mimics of protein thiols, is irreversible, and the resulting adducts are dissociated only by alkali treatment. On the other hand, PGA1 methyl ester reacts with soluble or polymer-anchored thiols at lower rates than Δ7-PGA1 methyl ester, but the resulting thiol adducts are substantially more stable than those of the dienone PGs. This tendency of the PGA1 methyl ester causes its equilibrium to shift to the adduct formation. The reversibility of the Michael reaction of PGs with thiols is consistent with their intracellular behavior and biological activities. Since glutathione adducts of PGs have no antiproliferative activities for cancer cells, the intracellular free PGs are presumed to interact with target molecules to cause cell growth inhibition. The involvement of the ATP-dependent glutathione S-conjugate export pump (GS-X pump) in the efflux of PGs is discussed. Thus, the marked difference in potency of the dienone and enone PGs is explained by considering the combined kinetic and thermodynamic properties and the action of the GS-X pump.
- Suzuki, Masaaki,Mori, Makoto,Niwa, Terutake,Hirata, Ryu,Furuta, Kyoji,Ishikawa, Toshihisa,Noyori, Ryoji
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p. 2376 - 2385
(2007/10/03)
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- Thiyl radicals in gas-phase thermolysis of xanthic acid esters
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Gas-phase thermolysis of xanthic acid esters and their reaction with acetylene at 250-600°C have been studied for the first time. The direction of the thermolysis is determined by the nature of the substituents at the oxygen and sulfur atoms. The main products of the thermolysis are gaseous hydrocarbons, carbon monoxide and hydrogen sulfide. The yields of liquid products of the thermolysis and of the reactions with acetylene are 4-46 %. The role of thiyl radicals in thiophene molecule formation and reaction routes to carbon disulfide, dithiocarbonates, and stilbene are discussed.
- Deryagina,Korchevin,Russavskaya,Sukhomazova,Levanova
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p. 140 - 143
(2007/10/03)
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- The Regioselective Reaction of Atomic Hydrogen with Unsymmetric Disulfides and Sulfides
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Unsymmetrical disulfides undergo solution phase reduction with atomic hydrogen regioselectively by displacement at the least hindered sulfur atom.The cleavage of the sulfur-sulfur bond forms mixtures of two thiol and two thiyl radicals.At the temperature at which the reactions are carried out, the thiyl radicals form symmetric disulfides by thiyl-thiyl radical coupling and not by thiyl radical displacement on the starting material.The reaction of atomic hydrogen with an unsymmetric sulfide is a cleavage that favors the formation of the most stable radical.The reaction of phenyl cyclohexyl sulfide produces benzene, cyclohexane, cyclohexyl thiol, and thiophenol.Benzene and cyclohexyl thiol produced from the cleavage of the phenyl-sulfur bond are proposed to arise from the α-scission of an intermediate formed by ipso-addition of atomic hydrogen to the benzene ring.
- Tanner, Dennis D.,Zhang, Liying,Vigneswaran, Markandu,Kandanarachchi, Pramod
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p. 4481 - 4487
(2007/10/02)
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- Studies on the Reaction of Iron Sulphide with Butan-1-ol in the Vapour Phase
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A new reaction of iron sulphide with butan-1-ol in the vapour phase a 359-500 deg producing mainly 1,1'-thiobis(butane) and 1,1-dibutoxybutane is reported.Iron sulphide (FeS) catalyses the formation of 1,1-dibutoxybutane and decomposition of 1-butane thiol.
- D'Souza, Ita M.,Banerjee, Anil C.
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p. 739 - 742
(2007/10/03)
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- Reaction of Sodium Aluminum Hydride with Selected Organic Compounds Containing Representative Functional Groups. Comparison of the Reducing Characteristics of Lithium and Sodium Aluminum Hydrides
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The approximate rate and stoichiometry of the reaction of excess sodium aluminum hydride (SAH) with organic compounds containing representative functional groups under standarized conditions (tetrahydrofuran, 0 deg C) were examined in order to define the reducing characteristics of the reagent and compare the reducing power with lithium aluminum hydride (LAH).In general, the reducing action and power of the reagent are similar to those of LAH.All of the active hydrogen compounds including alcohols, amines, and thiols evolve hydrogen instantly.Aldehydes and ketones are reduced very rapidly and quantitatively to give the corresponding alcohols.Unlike LAH, SAH reduces carboxylic acids and their salts only slowly to the corresponding alcohols.Similarly, anhydrides are reduced slowly to the diols.Acid chlorides, esters, and lactones consume 2 equiv of hydride in less than 15 min at 0 deg C to give the corresponding alcohols.However, the reaction of epoxides with this reagent proceeds at a much slower rate than LAH, requiring 6-24 h at 0 deg C and 1-6 h at room temperature.Both primary aliphatic and aromatic amides examined evolve 2 equiv of hydrogen rapidly and are reduced slowly to the alcohols.Tertiary amides rapidly utilize 2 equiv of hydride for reduction.The reaction of tertiary amides with a limiting amount of the reagent provides the aldehydes in yields of around 80percent.Benzonitrile also readily reacts to give the amine, while the reaction of capronitrile liberates ca. 0.4 equiv of hydrogen and consumes less than 2 equiv of hydride for reduction both at 0 deg C and room temperature.Aromatic nitro compounds examined also undergo the reaction readily to give the hydrazobenzene derivatives similar to the case with LAH.Oximes, phenyl isocyanate, disulfides, and sulfoxides are also readily reduced, while sulfides, sulfones, and tosylates are inert to this reagent.Finally, the similarities and differences in the reaction of organic compounds with LAH and SAH are established in this study.
- Cha, Jin Soon,Brown, Herbert C.
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p. 4727 - 4731
(2007/10/02)
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- Reaction of Aluminium Hydride-Triethylamine Complex with Selected Organic Compounds Containing Representative Functional Groups
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The addition of triethylamine to a solution of aluminium hydride in tetrahydrofuran (THF), which was prepared by the addition of a calculated amount of hydrogen chloride in diethyl ether to solutions of sodium aluminium hydride in THF, provides very stable solutions of aluminium hydride-triethylamine complex (AHTEA).The reducing power of AHTEA complex in tetrahydrofuran toward 59 selected organic compounds containing representative functional groups under practical conditions (tetrahydrofuran, room temperature, the quantitative amount of reagent to compound) has been investigated.In this way, we have established that quantitative reduction of various organic functionalities can be readily achieved using the calculated quantity of AHTEA to avoid the use of excess reagent.This permits ready use of the aluminium hydride reagent in organic synthesis with high convenience and efficiency, with the possibility of an improved selectivity than that of aluminium hydride itself in tetrahydrofuran.
- Cha, Jin Soon,Brown, Herbert C.
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p. 3974 - 3979
(2007/10/02)
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- Al-NiCl(2°)6H2O-THF: A new, mild and neutral system for selective reduction of organic functional groups
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A mild and neutral reducing system consisting of Al-NiCl(2°)6H2O-THF has been developed and reacted with a series of organic compounds containing different functional groups in order to evaluate its synthetic utility. It was observed that this system very efficiently reduces the α-enones to the saturated ketones, aromatic aldehydes and ketones to the corresponding alcohols, nitriles and nitroarenes to amines, acid anhydrides and acid chlorides to aldehydes, disulphides to thiols and epoxides to the corresponding alcohols. On the other hand isolated double bonds, carboxylic acids, esters, lactones, primary, benzyl and allyl halides, aliphatic aldehydes and ketones and aliphatic nitro compounds were found to remain inert to this system. Furthermore, the reducing properties of Al-NiCl(2°)6H2O in several other organic solvents were also studied.
- Sarmah,Barua
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p. 8587 - 8600
(2007/10/02)
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- HIGH-TEMPERATURE ORGANIC SYNTHESIS. XXXIV. THERMOLYSIS OF DIBUTYL POLYSULFIDES
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The main liquid product from the thermolysis of dibutyl polysulfides (C4H9)2Sn at 500-550 deg C is thiophene (maximum yield 43 percent with n = 3).The most thermally labile is dibutyl tetrasulfide, which decomposes even at 250 deg C.Above 350 deg C the tetrasulfide is also converted into 5-methyl-1,2-dithiole-3-thione, the yield of which amounts to 5-6percent.During the thermolysis of dibutyl disulfide in the presence of acetylene even at 400 deg C thiophene is formed with a yield of 70percent but in a mixture with benzene (yield 25 percent).
- Sukhomazova, E. N.,Turchaninova, L. P.,Korchevin, N. A.,Deryagina, E. N.,Voronkov, M. G.
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p. 1059 - 1062
(2007/10/02)
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- REDUCTIVE CLEAVAGE OF SULFUR OF SULFUR-SULFUR BONDS WITH SODIUM HYDROGEN TELLURIDE
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Sodium hydrogen telluride is shown to be an effective reagent for reduction of alkyl, aryl and functionally substituted disulfides to thiols in good yield under mild conditions.Organic thiosulfites (Bunte salt) also give thiols through the corresponding disulfide on reaction with sodium telluride.
- Kong, Fangming,Zhou, Xunjun
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p. 3143 - 3150
(2007/10/02)
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- Pressure Dependence of the Reaction of Thiolane with H and D Atom
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The title reaction was investigated at room temperature and under pressures ranging from 133 to 2660 Pa, using a conventional discharge flow reactor. 1-Butanethiol, butane, and 1-butene were the main products, whose compositions varied according to the pressure.In the reaction with deuterium atom, 1-butene was monodeuterated, while 1-butanethiol and butane were dideuterated.The following mechanism was proposed to account for the product compositions and their pressure dependencies as well as the deuterium labeling of the products.
- Tang, Jie,Kamo, Tohru,Yamada, Muneyoshi,Amano, Akira
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p. 3843 - 3848
(2007/10/02)
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- New Birch Type Reduction. Halogen or Halides-Activated Reduction of Disulfides to Thiols with Aluminium in Liquid Ammonia
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Aromatic and aliphatic disulfides were reduced to the corresponding thiols in high yields by new halogen or halides-activated Birch type reduction with aluminium in liquid ammonia.
- Sato, Ryu,Akaishi, Ryouichi,Goto, Takehiko,Saito, Minoru
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p. 773 - 774
(2007/10/02)
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- The Reaction of Dibutyl Disulfide with Hydrogen Atom
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The title reaction was investigated at room temperature and under pressures ranging from 133 to 2660 Pa. 1-Butanethiol, butane, and 1-butene were the main products.In the reaction with deuterium atom, dibutyldisulfide and 1-butanethiol were not deuterated
- Tang, Jie,Kamo, Tohru,Yamada, Muneyoshi,Ohshima, Yozo,Amano, Akira
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p. 2019 - 2022
(2007/10/02)
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- ONE POT CONVERSION OF ALKYL HALIDES INTO THIOLS UNDER MILD CONDITIONS
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Alkyl halides are converted into the corresponding thiols in good yields at room temperature under neutral conditions by reaction with 1-(2-hydroxyethyl)-4,6-diphenylpyridine-2-thione.
- Molina, P.,Alajarin, M.,Vilaplana, M. J.,Katritzky, A. R.
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p. 469 - 472
(2007/10/02)
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- Ate Complex from Diisobutylaluminum Hydride and n-Butyllithium as a Powerful and Selective Reducing Agent for the Reduction of Selected Organic Compounds Containing Various Functional Groups
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The "ate" complex generated from diisobutylaluminum hydride and n-butyllithium in an equimolar ratio either in tetrahydrofuran-hexane or in toluene-hexane was reacted with a series of selected organic compounds containing various functional groups in order to explore the reducing properties and to determine the synthetic utility of the reagent.The reagent is very effective for selective 1,2-reduction of both acyclic and cyclic enones.The reagent in tetrahydrofuran-hexane gives slightly better 1,2-selectivity than in toluene-hexane in the reduction of some acyclic enones, whereas the reagent in toluene-hexane gives better 1,2-selectivity in the reduction of conjugated cyclohexenones.Esters and lactones are completely reduced to the corresponding alcohols at room temperature, whereas they are reduced to the corresponding alcohols and aldehydes at -78 deg C even with an excess amount of the reagent.Partial reduction of the esters and the lactones to the corresponding aldehydes has not been observed.Acid chlorides are rapidly reduced to the corresponding alcohols with an excess amount of the reagent at -78 deg C, whereas they are reduced to a mixture of the alcohol, the aldehyde, and the unreacted acid chloride with a stoichiometric amount of the reagent at -78 deg C.Acid anhydrides are rapidly and quantitatively reduced to an equimolar mixture of the acid and the alcohol at -78 deg C.Carboxylic acids and primary and secondary amides are inert to the reagent at room temperature and are recovered unchanged..Tertiary amides are cleanly reduced to the aldehydes with a stoichiometric amount of the reagent either at 0 deg C or at room temperature, whereas they are inert to the reagent at -78 deg C, which permits the selective reduction of other reducible functional groups in the presence of the tertiary amide group at the latter temperature.The reagent rapidly reduces simple primary alkyl, benzyl, and allyl bromides but slowly primary alkyl chlorides and secondary alkyl bromides.Tertiary alkyl and aryl halides are essentially inert to the reagent, whereas trityl bromide and vinyl bromide are reduced at a reasonable rate.Epoxides are cleanly reduced to the corresponding alcohols.The opening of the epoxide ring with this reagent proceeds with excellent isomeric purity, yielding the more highly substituted alcohol almost exclusively.Nitriles are resistant to reduction and are only slowly converted to the corresponding aldehydes at room temperature.Disulfides are rapidly and quantitatively reduced to the corresponding thiols.Sulfoxides and sulfones are inert to the reagent and are recovered unchanged.Selective reductions of an ester in the presence of other reducible groups such as a bromide, a tertiary amide, and a nitrile are achieved with the reagent at -78 deg C by using a modified procedure.Furthermore, the reagent is capable of reducing selectively a ketone in the presence of an ester.
- Kim, Sunggak,Ahn, Kyo Han
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p. 1717 - 1724
(2007/10/02)
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- Selective Reductions: 33. Potassium Triisopropoxyborohydride as a Selective Reducing Agent in Organic Synthesis. Reaction with Selected Organic Compounds Containing Representative Functional Groups
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The approximate rate and stoichiometry of the reaction of excess pure potassium triisopropoxyborohydride, KIPBH, with 56 selected compounds containing representative functional groups under standardized conditions (tetrahydrofuran, 0 deg C) was examined in order to define the characteristics of the reagent for selective reductions.Primary, secondary, and tertiary alcohols evolve hydrogen partially, even after a long period of time.Phenol also generates partial hydrogen, and the reactions of those amines and thiols studied with the reagent are very slow.Aldehydes andketones are reduced rapidly and quantitatively to give the corresponding alcohols.Unlike sodium and potassium borohydrides, KIPBH is very stereoselective. 2-Methylcyclohexanone can be reduced to the correspondingly less stable isomer, cis-2-methylcyclohexanol, in a high ratio (91percent cis isomer).Cinnamaldehyde is rapidly reduced to cinnamylalcohol, and further reduction is very slow under these conditions.Anthraquinone is cleanly reduced to 9,10-dihydro-9,10-anthracenediol.Carboxylic acids liberate hydrogen only partially, and further reduction is very slow.Acid chlorides consume 1 equiv of hydride rapidly, but the corresponding aldehydes do not form.Esters are almost inert toward the reagent. γ-Butyrolactone and phthalide are reduced only slowly.Epoxides are inert toward the reagent.Primary aliphatic amides evolve hydrogen slowly and primary aromatic amides evolve 1 equiv of hydrogen, but no significant reduction occurs.Tertiary amides and nitriles are inert toward the reagent.Of the nitrogen compounds studied, nitrobenzene is partially reduced after 48h, while azobenzene and azoxybenzene are inert.Partial reduction ofcyclohexanone oxime is observed, while phenyl isocyanate, pyridine, and pyridine N-oxide are inert under these conditions.Di n-butyl disulfide and diphenyl disulfide are reduced rapidly and quantitatively to the corresponding mercaptans with partial hydrogen evolution.Other sulfur compounds studied, such as p-tolyl methyl sulfide, diphenylsulfone, methanesulfonic acid, and p-toluenesulfonic acid, are inert toward the reagent.Only partial reduction of cyclohexyl tosylate is observed.Potassium triisopropoxyborohydride is a valuable reagent in boron chemistry.Thus, it transfers 1 equiv of hydride to dialkylhaloboranes, and the resulting dialkylborane can be transformed to a mixed trialkylborane, providing a potential route to mixed trialkylcarbinols or unsymmetrical ketones.The reagent rapidly transfers hydride to even severely hindered trialkylboranes, providing a simple synthetic route to these useful reagents.Finally, it readily converts 2-bromo-trans-vinylboronic esters to the cis-vinylboronic esters, providing a convenient synthetic route to these derivatives.
- Brown, Herbert C.,Cha, Jin Soon,Nazer, Behrooz,Kim, Suk-Choong,Krishnamurthy, Sundaram
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p. 885 - 892
(2007/10/02)
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- A Method for the Simultaneous Preparation of Alkyl Isothiocyanates and Thiols
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Aus primaeren Alkylaminen wurden Ethyl-, Butyl-, Isobutyl- und n-Dodecyldithiocarbamate 2 hergestellt.Letztere lassen sich leicht zu den Isothiocyanaten 3 und Thiolen 4 pyrolisieren.Die Massenspektren der Ester sowie deren Pyrolyseprodukte wurden gemessen.
- Blotny, Grzegorz
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p. 1927 - 1932
(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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- Rate and Equilibrium Constants for the Reaction of Thiolate Ions with Dibenzo-1,2-dithiin and Naphtho-1,2-dithiole 1,1-Dioxides
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In aqueous dioxane the cyclic thiosulfonate dibenzo-1,2-dithiin 1,1-dioxide (1) reacts rapidly with thiolate ions and undergoes opening of the thiosulfonate ring (eq 2), forming disulfide 3a.Acidification of solutions of 3a with carboxylic acid buffers of appropiate pH leads to facile reversal of ring-opening reaction and the quantitative regeneration of 1.Since this reversal of ring opening is not acid-catalyzed, it must take place via a simple intramolecular displacement of RS- by the sulfinate (SO2-) group present in 3a and is therefore the microscopic reverse of the ring-opening reaction.Rate constants have been determined for both ring opening (kRS) and reversal of ring opening (k-RS) for a series of alkanethiolates of varying pKa.From these data one may also calculate the equilibrium constant, Keq(=kRS/k-RS), for reaction of each thiolate with 1.From comparison of the log Keq's with previously determined equilibrium constants for reaction of cyanide and sulfite ions with 1 one obtains quantitative information on the thermodynamics of reactions of the type ArSSR + CN- = ArSCN + RS- and ArSSR + SO32- = ArSSO3- + RS- that should be of considerable value for predicting the magnitude of equilibrium constants for cyanide-disulfide and sulfite-disulfide equilibria.Plots of log Keq, log KRS, and log k-RS vs. the pKa of RSH reveal that βeq=1.25, βRS=0.26, and β-RS=-0.99.These β values show that the transition state for eq 2 is quite unsymmetrical, with a structure Δ-...S-SO2δ-> where the RS-S bond is only ca. 20percent formed.The βRS and β-RS values are compared with the β values for several other previously studied displacements involving disulfides.The reaction of naphthol-1,2-dithiole 1,1-dioxide (2) with thiolates behaves in a fashion analogous to that of the reaction of RS- with 1.Comparison of Keq, kRS, and k-RS for an equilibrium involving 2 and a thiolate with those for the corresponding thiolate reacting with 1 allows one to assess how a change from a six- to a five-membered thiosulfonate ring influences Keq, kRS, and k-RS.The major effects are that k-RS is much larger and Keq is considerably smaller.
- Boduszek, Bogdan,Kice, John L.
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p. 2055 - 2060
(2007/10/02)
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- A Novel Method for the Preparation of Thioformates and Thiols by using Thioformimidates
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Several new S-alkylated thioformimidates were synthesized and their applications to the synthesis of thiolformates and thiols were investigated.Keywords - thioformimidates; thiols; thiolformates; thioformanilide; Michel-type addition
- Matsubara, Yoshio,Nakamura, Toshiyuki,Yoshihara, Masakuni,Maeshima, Toshihishi
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p. 3389 - 3391
(2007/10/02)
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- Reactions of Thiols with Phenylglyoxal to Give Thiomandelic S-Esters Formation of Hemithioacetals and Their Rearrangement
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Equilibrium constants Kh for the addition of 2-mercaptoethanol and glutathione to phenylglyoxal to form hemithioacetals were determined spectrophotometrically over the pH range 7-10.The observed Kh values decrease sigmoidally with pH as the thiol ionizes.Rearrangement of hemithioacetals formed from phenylglyoxal and various thiols was kinetically investigated.The rates increase with thiol concentration following a saturation curve to give Kh identical with the spectrophotometric value.The rearrangement is subject to general base catalysis.The solvent isotope effect on the rate of the rearrangement, kH2O/kd2O, is nearly 1.0; that on the equilibrium, KH2Oh/KD2Oh, is 0.38.The results strongly support the mechanism involving proton transfers through an enediol intermediate.
- Okuyama, Tadashi,Kimura, Kazumasa,Fueno, Takayuki
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p. 1493 - 1497
(2007/10/02)
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- Mechanism of Hydrolysis of Hydroxy Thiolesters in the Presence of Boric Acid
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The catalytic effect of boric acid on the hydrolysis of S-butyl 2-hydroxy-2-phenylthioacetate (thiomandelate, 1) and 3-hydroxy-3-phenylthiopropionate (2) has been investigated in aqueous solution.The catalytic constants increased sigmoidally with increasing pH, the pKa of the curve being 9.2 for both 1 and 2.Approximate Hammett ρ values were 1.2 and 0.6 for the alkaline and borate-catalyzed hydrolyses of ring-substituted derivatives of 1, respectively.Boric acid did not show any specific influence on the hydrazinolysis of 1.Thise results lead to the conclusion that the borate catalysis occurs through an intramolecular transfer of the boron-coordinated hydroxide ion to the carbonyl carbon within a borate-substrate complex.
- Okuyama, Tadashi,Nagamatsu, Hiroaki,Fueno, Takayuki
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p. 1336 - 1342
(2007/10/02)
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- PHOSPHORORGANISCHE VERBINDUNGEN 97. Die Diphenylphosphinyl- und die Diphenylthiophosphinylgruppe als selektive Schutzgruppe fuer die Mercaptofunktion. Nucleophile Abloesung der Thioloestergruppe aus Thiophosphin-, Thiophosphon- und Thiophosphorsaeure-S-estern durch nicht solvatisierte...
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Diphenylphosphinic acid cyanide and diphenylthiophosphonic acid cyanide react selectively with the mercaptogroup even in presence of primary aminogroups.The thioloesterbond in thiophosphinic, thiophosphonic and thiophosphoric acid S-esters is cleaved under mild conditions by unsolvated fluoride ions F*3H2O (R = C4H9) and CsF> in methylene chloride, chloroform or THF. (C6H5)2P(O)CN and (C6H5)2P(S)CN are therefore protecting group reagents for mercaptans.Diphenylphosphinic acid chloride and diphenylthiophosphinic acid chloride are N-selective in competing reactions using butylamine/butylmercaptan.In contrast to the corresponding S-selective cyanides no selectivity is observed using cysteamine and cysteinmethylester.
- Horner, L.,Gehring, R.,Lindel, H.
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p. 349 - 356
(2007/10/02)
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- POSSIBILITY OF SYNTHESIZING THIOLS FROM TRIALKYL BORATE
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The possibility of obtaining thiols from trialkyl borates and hydrogen sulfide was investigated.The best yeilds (up to 32percent) were obtained with FeS as catalyst at pressures of 25-30 atm and temperatures of 300-400 deg C.Dialkyl sulfides are not formed in appreciable amounts.
- Savel'yanov, V.P.,Dokukin, N.I.,Savel'yanova, R.T.
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p. 816 - 817
(2007/10/02)
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- Rate Constants and Equilibrium Constants for Thiol-Disulphide Interchange Reactions Involving Oxidized Glutathione
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The rate of reduction of oxidized glutathione (GSSG) to glutathione (GSH) by thiolate (RS-) follows a Broensted relation in pKas of the conjugate thiols (RSH): βnuc ca. 0.5.This value is similar to that for reduction of Ellman's reagent: βnuc ca. 0.4 - 0.5.Analysis of a number of rate and equilibrium data, taken both from this work and from the literature, indicates that rate constants, k, for a range of thiolate-disulphide interchange reactions are correlated well by equations of the form log k = C + βnucpKanuc + βcpKac + βlgpKalg ( nuc = nucleophile, c = central, and lg = leaving group sulfur): eq 36 - 38 give representative values of the Broensted coefficients.The values of these Bronsted coefficients are not sharply defined by the available experimental data, although eq 36 - 38 provide useful kinetic models for rates of thiolate-disulfide interchange reactions.The uncertainty in these parameters is such that their detailed mechanistic interpretation is not worthwhile, but their qualitative interpretation - that all three sulphur atoms experience a significant effective negative charge in the transition state, but that the charge is concentrated on the terminal sulfurs - is justified.Equilibrium constants for reduction of GSSG using α,ω-dithiols have been measured.The reducing potential of the dithiol is strongly influenced by the size of the cyclic disulfide formed on its oxidation: the most strongly reducing dithiols are those which can form six-membered cyclic disulfides.Separate equilibrium constants for thiolate anion-disulphide interchange (KS-) and for thiol-disufide interchange (KSH) have been estimated from literature data: KS- is roughly proportional to 2ΔpKa is the difference between the pKas of the two thiols involved in the interchange.The contributions of thiol pKa values to the observed equilibrium constants for reduction of GSSG with α,ω-dithiols appear to be much smaller than those ascribable to the influence of structure on intramolecular ring formation.These equilibrium and rate constants are helpful in choosing dithiols for use as antioxidants in solutions containing proteines: dithiothreitol (DTT), 1,3-dimercapto-2-propanol (DMP), and 2-mercaptoethanol have especially useful properties.
- Szajewski, Richard P.,Whitesides, George M.
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p. 2011 - 2026
(2007/10/02)
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- Antibacterial compounds
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A thiol acid and esters thereof of formula (II): STR1 wherein R is hydrogen, a salt forming ion or a pharmaceutically acceptable ester-forming radical, have antibacterial and antimycoplasmal activity and are therefore useful in the treatment of human and veterinary bacterial and mycoplasmal infections.
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- The Reductive Acylation of Organic Disulfides with Aldehydes under Photochemical and Radical Conditions
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The irradiation of organic disulfides in aldehyde solvents resulted in the reductive fission of the S-S linkage, giving an equimolar mixture of the corresponding thiol and thiol acylate in a good yield.The cyclic disulfides gave mono S-acylated dithiols.The reaction proceeded by means of the photo-initiated radical chain mechanism, and AIBN (azobisisobutyronitrile) effected the same reaction under thermal conditions.
- Takagi, Makoto,Goto, Setsuo,Tazaki, Masato,Matsuda, Tsutomu
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p. 1982 - 1987
(2007/10/02)
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