- Competition between surfactant micellization and complexation by cyclodextrin
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Supramolecular property systems composed of alkyltrimethylammonium surfactants and β-cyclodextrin were studied by means of a chemical probe. Solvolysis of 4-methoxybenzenesulfonyl chloride (MBSC) was used in the mixed systems with the aim of being able to
- Cepeda,Davi?a,García-Río,Parajó,Rodríguez-Dafonte,Pessêgo
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Read Online
- Cyclodextrin-surfactant binding constant as driven force for uncomplexed cyclodextrin in equilibrium with micellar systems
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Mixed systems formed by surfactants, sodium alkylsulfonates, and β-cyclodextrin have been studied by using the solvolysis of 4-methoxybenzenesulfonil chloride (MBSC) as a chemical probe. The kinetic analysis allows us to obtain the percentage of uncomplex
- Cepeda,Davi?a,García-Río,Parajó
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Read Online
- Self-aggregation properties of ionic liquid 1,3-didecyl-2-methylimidazolium chloride in aqueous solution: From spheres to cylinders to bilayers
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The self-aggregation behavior of the double-chained ionic liquid (IL) 1,3-didecyl-2-methylimidazolium chloride ([C10C10mim]Cl) in aqueous solution has been investigated with a number of different experimental techniques. Two cmc valu
- Figueira-Gonzalez, Maria,Francisco, Vitor,Garcia-Rio, Luis,Marques, Eduardo F.,Parajo, Mercedes,Rodriguez-Dafonte, Pedro
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Read Online
- Cucurbit[7]uril: Surfactant host-guest complexes in equilibrium with micellar aggregates
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In order to compare the formation of host-guest complexes between β-cyclodextrin (β-CD) or cucurbit[7]uril (CB7) and cationic surfactants we studied the hydrolysis of 4-methoxybenzenesulfonyl chloride (MBSC). The selected surfactants allowed the length of
- Pessego, Marcia,Basilio, Nuno,Moreira, Jose A.,Garcia-Rio, Luis
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Read Online
- γ-Cyclodextrin modulates the chemical reactivity by multiple complexation
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Multiple complexation by γ-CD has been studied by self-diffusion coefficients (DOSY) and chemical kinetics experiments in which 4-methoxybenzenesulfonyl chloride (MBSC) solvolysis was used as a chemical probe. The addition of a surfactant as a third compo
- Fernández-Rosas,Pessêgo,Cepeda-Plaza,Basilio,Parajó,Rodríguez-Dafonte,García-Río
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Read Online
- Cornforth and Corey-Suggs reagents as efficient catalysts for sulfonation of aromatic and heteroaromatic compounds using NaHSO3 under solvent free and microwave conditions
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Cornforth and Corey-Suggs reagents Pyridinium Dichromate (PDC) and Pyridinium Chlorochromate (PCC) were explored as efficient catalysts for sulfonation of aromatic and heteroaromatic compounds using NaHSO3 in aqueous acetonitrile medium at room temperature within 1–4 h, while microwave assisted reactions took place within 1–4 min under solvent-free conditions. These observations indicate significant rate accelerations in microwave assisted reactions. which were explained due to the bulk activation of molecules induced by insitu generated high temperatures and pressures when microwaves are transmitted through reaction medium.
- Fatima, Touheeth,Duguta, Govardhan,Purugula, Venkanna,Yelike, Hemanth Sriram,Kamatala, Chinna Rajanna
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p. 1001 - 1006
(2020/07/27)
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- Sustainable access to sulfonic acids from halides and thiourea dioxide with air
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A sustainable and mild one-step strategy is explored for the synthesis of aryl and alkyl sulfonic acids using a facile combination of halides and sulfur dioxide surrogates under air. The cheap industrial material thiourea dioxide was employed as an eco-friendly and easy-handling sulfur dioxide surrogate, while air was used as a green oxidant. Both aryl and alkyl sulfonic acids were obtained under transition metal-catalyzed or transition metal-free conditions. Mechanistic studies demonstrated that sulfinate was involved as an intermediate in this transformation. Notably, this protocol has been applied to the late-stage sulfonation of the drugs naproxen, isoxepac and ibuprofen.
- Zhang, Hui,Wang, Ming,Jiang, Xuefeng
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supporting information
p. 8238 - 8242
(2020/12/29)
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- Aryl and alkyl sulfonic acid compounds as well as construction method adopting inorganic sulfur salt and application
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The invention discloses aryl and alkyl sulfonic acid compounds as shown in a formula (1) and a synthesis method thereof. The method comprises the following step: aromatic iodine and an inorganic sulfur source or alkyl bromide and an inorganic sulfur source as reaction raw materials react in a solvent under the action of alkali, a catalyst or an additive to obtain a series of aryl and alkyl sulfonic acid compounds. According to the method, the aryl and alkyl sulfonic acid compounds are constructed in one step by taking an inorganic sulfur reagent as a sulfur source, so that the defect of the mode in which the aryl and alkyl sulfonic acid compounds are synthesized by taking concentrated sulfuric acid, chlorosulfonic acid or sulfur dioxide gas and the like as sulfonating reagents in the priorart is avoided. The aryl and alkyl sulfonic acid compounds developed by the invention can be used for synthesizing aryl and alkyl sulfonic acid drug analogues.
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Paragraph 0046-0049; 0050-0054
(2020/09/16)
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- Silver-Mediated Trifluoromethoxylation of (Hetero)aryldiazonium Tetrafluoroborates
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Here we report a silver-mediated trifluoromethoxylation of (hetero)aryldiazonium tetrafluoroborates by converting an aromatic amino group into an OCF3 group. This method, which can be considered to be a trifluoromethoxylation variation of the classic Sandmeyer-type reaction, uses readily available aryl and heteroaromatic amines as starting materials and AgOCF3 as trifluoromethoxylating reagents. The broad substrate scope and simple, mild reaction condition made this transformation a valuable method in constructing aryl-OCF3 bonds.
- Yang, Yu-Ming,Yao, Jian-Fei,Yan, Wei,Luo, Zhuangzhu,Tang, Zhen-Yu
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supporting information
p. 8003 - 8007
(2019/10/11)
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- Selective Late-Stage Sulfonyl Chloride Formation from Sulfonamides Enabled by Pyry-BF4
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Reported here is a simple and practical functionalization of primary sulfonamides, by means of a pyrylium salt (Pyry-BF4), with nucleophiles. This simple reagent activates the poorly nucleophilic NH2 group in a sulfonamide, enabling the formation of one of the best electrophiles in organic synthesis: a sulfonyl chloride. Because of the variety of primary sulfonamides in pharmaceutical contexts, special attention has been focused on the direct conversion of densely functionalized primary sulfonamides by a late-stage formation of the corresponding sulfonyl chloride. A variety of nucleophiles could be engaged in this transformation, thus permitting the synthesis of complex sulfonamides, sulfonates, sulfides, sulfonyl fluorides, and sulfonic acids. The mild reaction conditions and the high selectivity of Pyry-BF4 towards NH2 groups permit the formation of sulfonyl chlorides in a late-stage fashion, tolerating a preponderance of sensitive functionalities.
- Gómez-Palomino, Alejandro,Cornella, Josep
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supporting information
p. 18235 - 18239
(2019/11/13)
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- Guaiacol intermediate and preparation method thereof
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The invention provides a guaiacol intermediate. A structure formula of the guaiacol intermediate is as shown in the description. The invention also provides a preparation method of the guaiacol intermediate. The preparation method comprises the following
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Paragraph 0031; 0032; 0033
(2016/10/10)
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- Nucleophilic Substitution Reactions of 2,4-Dinitrophenyl X-Substituted-Benzenesulfonates and Y-Substituted-Phenyl 4-Nitrobenzenesulfonates with Azide Ion: Regioselectivity and Reaction Mechanism
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The second-order rate constants for reactions of 2,4-dinitrophenyl X-substituted-benzenesulfonates (4a-4f) and Y-substituted-phenyl-4-nitrobenzenesulfonates (5a-5f) with N3- ion have been measured spectrophotometrically. The reactions of 4a-4f proceed through S-O and C-O bond fission pathways competitively. Fraction of the S-O bond fission decreases rapidly as the substituent X in the benzenesulfonyl moiety changes from an electron-withdrawing group to an electron-donating group. The Hammett plots for reactions of 4a-4f are linear with ρX=1.87 and 0.56 for the S-O and C-O bond fission, respectively. The fact that the substituent X is further away from the reaction site of the C-O bond fission than that of the S-O bond fission is one reason for the smaller ρX value. The nature of the reaction mechanism (i.e., a stepwise mechanism in which expulsion of the leaving group occurs after the rate-determining step) is also responsible for the smaller ρX value obtained from the C-O bond fission. The Bronsted-type plot for the reactions of 5a-5f is linear with βlg=-0.63, which is typical for reactions reported previously to proceed through a concerted mechanism. Effects of substituents X and Y on regioselectivity and reaction mechanism are discussed in detail.
- Moon, Ji-Hyun,Kim, Min-Young,Han, So-Yeop,Um, Ik-Hwan
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p. 1360 - 1365
(2015/07/15)
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- Synthesis of sulfonyl chlorides and sulfonic acids in SDS micelles
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H2O2/POCl3 is found to be a reactive reagent system that can be used in sodium dodecyl sulfate (SDS) micellar solution in aqueous media for the direct oxidative chlorination of thiol and di-sulfide derivatives to give the desired sulfonyl chlorides. The oxidation of thiols and disulfides to sulfonic acids with this system is also reported. In most cases, these reactions are highly selective, simple, and clean, affording products in excellent yields and high purity. Georg Thieme Verlag Stuttgart · New York.
- Bahrami, Kiumars,Khodaei, Mohammad M.,Abbasi, Jamshid
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experimental part
p. 316 - 322
(2012/03/26)
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- The SN3-SN2 spectrum. Rate constants and product selectivities for solvolyses of benzenesulfonyl chlorides in aqueous alcohols
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Rate constants for a wide range of binary aqueous mixtures and product selectivities (S) in ethanol - Water (EW) and methanol-water (MW) mixtures, are reported at 25 °C for solvolyses of benzenesulfonyl chloride and the 4-chloro - Derivative. S is defined as follows using molar concentrations: S =([ester product]/[acid product]) × ([water solvent]/[alcohol solvent]). Additional selectivity data are reported for solvolyses of 4-Z-substituted sulfonyl chlorides (Z - OMe, Me, H, Cl and NO2) in 2, 2, 2-trifluoroethanol-water. To explain these results and previously published data on kinetic solvent isotope effects (KSIEs) and on other solvolyses of 4-nitro and 4-methoxybenzenesulfonyl chloride, a mechanistic spectrum involving a change from third order to second order is proposed. The molecularity of these reactions is discussed, along with new term 'SN3-SN2 spectrum' and its connection with the better established term 'S N2-SN1 spectrum'. Copyright
- Bentley, T. William,Jones, Robert O,Kang, Dae Ho,Koo, Sun
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scheme or table
p. 799 - 806
(2010/06/16)
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- Selective oxidation reactions of diaryl- and dialkyldisulfides to sulfonic acids by CH3ReO3/hydrogen peroxide
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Diaryl- and dialkyl disulfides were oxidized in acetonitrile at 20 °C by CH3ReO3/H2O2 oxidant system to yield selectively the corresponding sulfonic acids in short reaction times and in high yields.
- Ballistreri, Francesco P.,Tomaselli, Gaetano A.,Toscano, Rosa M.
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experimental part
p. 6231 - 6232
(2010/01/11)
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- Selective and mild oxidation of thiols to sulfonic acids by hydrogen peroxide catalyzed by methyltrioxorhenium
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Aromatic and aliphatic thiols are oxidized in acetonitrile at 20 °C by hydrogen peroxide in the presence of methyltrioxorhenium as the catalyst to yield the corresponding sulfonic acids in high isolated yields (85-94%).
- Ballistreri, Francesco P.,Tomaselli, Gaetano A.,Toscano, Rosa M.
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p. 3291 - 3293
(2008/09/20)
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- Effect of Amine Nature on Reaction Rate and Mechanism in Nucleophilic Substitution Reactions of 2,4-Dinitrophenyl X-Substituted Benzenesulfonates with Alicyclic Secondary Amines
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Second-order rate constants have been measured for reactions of 2,4-dinitrophenyl X-substituted benzenesulfonates with a series of alicyclic secondary amines. The reaction proceeds through S-O and C-O bond fission pathways competitively. The S-O bond fission occurs more dominantly as the amine basicity increases and the substituent X in the sulfonyl moiety becomes more strongly electron withdrawing, indicating that the regioselectivity is governed by the amine basicity as well as the electronic nature of the substituent X. The S-O bond fission proceeds through an addition intermediate with a change in the rate-determining step at pKa° = 9.1. The secondary amines are more reactive than primary amines of similar basicity for the S-O bond fission. The k1 value has been determined to be larger for reactions with secondary amines than with primary amines of similar basicity, which fully accounts for their higher reactivity. The second-order rate constants for the S-O bond fission result in linear Yukawa-Tsuno plots while those for the C-O bond fission exhibit poor correlation with the electronic nature of the substituent X. The distance effect and the nature of reaction mechanism have been suggested to be responsible for the poor correlation for the C-O bond fission pathway.
- Um, Ik-Hwan,Chun, Sun-Mee,Chae, Ok-Mi,Fujio, Mizue,Tsuno, Yuho
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p. 3166 - 3172
(2007/10/03)
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- A novel method for sulfonation of aromatic rings with silica sulfuric acid
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Direct and chemoselective sulfonation of aromatic compounds with silica sulfuric acid in 1,2-dichloeoethane or under solvent-free conditions.
- Hajipour, Abdol R.,Mirjalili, Bi Bi F.,Zarei, Amin,Khazdooz, Leila,Ruoho
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p. 6607 - 6609
(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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- Phenylthio-derivatives of α-methylene-γ-lactones as pro-drugs of cytotoxic agents
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A series of substituted phenylthio-derivatives of grosheimin (1), a natural cytotoxic guaianolide, were investigated with the aim of providing insight into their mechanism of action as cytotoxic agents against KB cell lines. Hydrolysis data, kinetics, in the presence and in the absence of H2O2, and the valuation of lipophilicity were correlated with cytotoxicity values and with Hammett-σ-values of substituents (R) at the thiophenol ring. These compounds behave as 'pro-drugs' which release the cytotoxic agent grosheimin by sulphur-oxidation promoted by H2O2 and subsequent retro- elimination which depends on the nature and position of the R substituent.
- Fardella, Giuseppe,Barbetti, Paolo,Grandolini, Giuliano,Chiappini, Ione,Ambrogi, Valeria,Scarcia, Vito,Furlani Candiani, Ariella
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p. 515 - 523
(2007/10/03)
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- Quantitative Study of Cooperative Effect of Excess Acidity, Nature of Substituent, and Temperature on Hydrolysis Rate of Aromatic Sulfonyl Chlorides in Sulfuric Acid
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Based on the methods of multiple linear regression, polylinearity, and particular electronic effects of substituents, a treatment is made of the published data on the pseudomonomolecular hydrolysis rate constants in sulfuric acid (0-60 wt % H2S
- Ivanov,Kislov,Gnedin
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p. 1123 - 1128
(2007/10/03)
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- Reactivity of sterically hindered aromatic sulfonic acid derivatives: VII.* hydrolysis of arenesulfonyl chlorides in aqueous acetonitrile
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Hydrolysis of sterically hindered arenesulfonyl chlorides in aqueous acetonitrile is accelerated by both electron-acceptor and some electron-donor substituents in the benzene ring. A multifactor kinetic model of the process is proposed. 1998 MAHK Hayka/Interperiodica Publishing.
- Rubleva,Krut'ko,Mitchenko
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p. 1006 - 1009
(2007/10/03)
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- Oxidative hydrolysis of phosphorus(V) esters of thiols by peroxymonosulfate ion. Reactions of peroxymonosulfate ion with phosphorus(V) esters of thiols
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Peroxymonosulfate ion, HSO5-, as Oxone, readily converts phosphorus(V) esters of thiols into the phosphorus(V) and sulfonic acids. The esters were Ph2PO·SC6H4R(p) with R=MeO (1a), Me (1b), H (1c), Cl (1d) and NO2 (1e), (EtO)2PO·SPh (2), Ph2OI·SEt (3) and PhPO(OEt)SEt (4). Reactions are first order in each reactant and second-order rate constants, k2, for 1a-e fit the Hammett equation with ρ=-0.46. The rate constants increase markedly with increasing water content of H2O-MeCN, the activation enthalpies are low and the entropies are negative. Despite the low value of -ρ, these esters are much less reactive than thiol ethers, but the rate constants of reactions of these compounds and acyl thiols qualitatively follow the ionization potentials of the ethers and the esters.
- Blasko, Andrei,Bunton, Clifford A.,Kumar, Anurag
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p. 427 - 434
(2007/10/03)
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- Sulfide Oxidation and Oxidative Hydrolysis of Thioesters by Peroxymonosulfate Ion
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Peroxymonosulfate ion, HSO5-, as OXONE, in aqueous MeCN readily converts aryl thiobenzoates, XC6H4CO*SC6H4Z (X = p-OMe, p-Me, H, p-Cl, p-CN; Z = p-OMe, p-Me, H, m-OMe, p-Cl, m-Cl, p-NO2) into carboxylic and sulfonic acids.Reactions are second order and have small substituent effects, with ρ ca. -0.6 based on ?m and ?p substituent parameters, but rates increase markedly with increasing water content in aqueous MeCN and entropies of activation are negative.The initial step is very similar to the oxidation of methyl aryl sulfides by HSO5- which has similar solvent and substituent effects.Enthalpies of activation are much lower for oxidation of the sulfides than of the corresponding esters but entropies of activation are similar.
- Bunton, Clifford A.,Foroudian, Houshang J.,Kumar, Anurag
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- Reactions of sulfur trioxide with benzene derivatives containing a deactivating oxy substituent
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The reactions of phenyl acetate (2), (trifluoromethoxy)benzene (3), (difluoromethoxy)benzene (4), 4-(trifluoromethoxy)phenol (5), 4-(trifluoromethoxy)phenyl methanesulfonate (6), 4-(trifluoromethoxy)anisole (7) and 3-(trifluoromethoxy)anisole (8) with SO3 in nitromethane have been studied.Upon reaction with SO3, 2 yields 2-4-sulfonic acid (2-4-S); subsequently, transfer of the acetyl group takes place to yield the mixed anhydride of phenol-4-pyrosulfonic acid and acetic acid (9) or the corresponding hydrogen sulfate 10, depending on the amount of SO3 used.Reaction of the α-fluorinated anisoles 3 and 4 with SO3 leads to sulfonation at the 4-position only; however, on using both a high substrate concentration and an excess of SO3, some 2,4-S2 is formed with 4 but not with 3.On reaction of 5 with 0.8 mol-equiv of SO3 in C(2)H3NO2, the hydrogen sulfate derivative (5-O-S) is formed; at 100 deg C, some isomerization to 5-2-S occurs.Upon reaction with 4.0 mol-equiv of SO3, the initially formed hydrogen sulfate slowly yields the corresponding 2-sulfophenyl hydrogen sulfate (5-O,2-S2).On using 6.0 mol-equiv of SO3, the 5-O,2-S2 is slowly converted into 6-(trifluoromethoxy)benzo-1,3,2,4-dioxadithiin 2,2,4,4-tetraoxide (11).Reaction of 6 with either 0.9 or 3.0 mol-equiv of SO3, initially leads to insertion of sulfur trioxide in between the SO2CH3 and the adjacent O, yielding the 4-(trifluoromethoxy)phenyl methanepyrosulfonate 12.This species subsequently yields 13 and 14.Reaction of 7 with SO3 leads to sulfonation only at the 2-position; eventually some sulfodemethylation to yield 5-2-S takes place.Reaction of 8 with 1.0 mol-equiv of SO3 yields a 68:32 mixture of 8-4-S and 8-6-S.
- Ansink, Harold R. W.,Cerfontain, Hans
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p. 215 - 221
(2007/10/02)
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- Sulphonyl Transfer Reactions: Solvolysis of Arenesulphonyl Chlorides in Aqueous Trifluoroethanol
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Activation parameters for the solvolysis in aqueous trifluoroethanol of arenesulphonyl chlorides with electron-supplying substituents have been determined; the results are not in accord with earlier proposals that such compounds reacts by an SN1 mechanism.
- Forbes, Rowena M.,Maskill, H.
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p. 854 - 856
(2007/10/02)
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- Limitations of the Transition-state Variation Model. Part 3. Solvolyses of Electron-rich Benzenesulphonyl Chlorides
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Rate constants for solvolyses of 4-methoxy-2,6-dimethylbenzenesulphonyl chloride 3 (Z = OMe) and of 4-methyl- and 4-methoxybenzenesulphonyl chlorides 4 (Z = Me and OMe) are reported for aqueous binary mixtures with acetone, ethanol and methanol.Some additional rate constants are reported for aqueous acetonitrile and dioxane mixtures, as well as product selectivities (S) in alcohol-water mixtures.For each binary mixture, rates of solvolyses of 3 (Z = OMe) vs.YCl or Y are approximately bilinear.As water is added to alcohol, S values for solvolyses of 3 (Z = OMe) pass through a maximum and for solvolyses of 4-methoxybenzenesulphonyl chloride 4 (Z = OMe) the position of the maximum shifts to more aqueous media.For solvolyses of 4-methyl-benzenesulphonyl chloride 4 (Z = Me), S values are shifted such that they reach a plateau rather than a maximum, and the rate-rate profiles with YCl are approximately linear rather than bilinear.All of rate-rate profiles show 'dispersion' into separate correlations for the various binary mixtures.These substituent effects follow the same trends as corresponding solvolyses of benzoyl chloride and strengthen recent proposals that solvolyses of 3 (Z = Me) proceed via competing (dual) reaction channels.
- Koo, In Sun,Bentley, William T.,Llewellyn, Gareth,Yang, Kiyull
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p. 1175 - 1179
(2007/10/02)
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- REACTIONS OF ALKENES AND Ω-PHENYLALKENES WITH SULFUR TRIOXIDE; SULFONATION AND FRIEDEL-CRAFTS TYPE OF CYCLIZATION
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Reaction of alkenes with SO3 leads to the formation of β-sultones, carbyl sulfates, alkenesulfonic acids and γ-sultones, depending on the alkene structure and on the reaction conditions.The high selectivity for the cyclisation to 1,2,3,4-tetrahydronaphthalene sulfonic acid derivatives on reaction of well chosen ω-phenylalkenes with SO3 infers the occurence of a relatively fast equilibrium between ω-phenyl-m,n- and the ω-phenyl-n,m-alkanesultone intermediate.
- Schonk, Ruud M.,Bakker, Bert H.,Cerfontain, Hans
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p. 173 - 176
(2007/10/02)
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- Acid-catalyzed transfer sulfonation of anisole using overcrowded polymethylbenzenesulfonic acids
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Transfer sulfonations of anisole using various polymethylbenzenesulfonic acids (PoMBR's) catalyzed by trifluoromethanesulfonic acid at 25 deg C are described.The observed reactivity order for transfer sulfonation increases in the order 2,4-DiMBS, 2,6-DiMB
- Koeberg-Telder, Ankie,Cerfontain, Hans
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- Multiple Structure-Reactivity Relationships for a Menschutkin-type SN2 Reaction
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The mechanism of nucleophilic displacement was studied by using three variable systems of ρX, ρY and ρZ obtained from the change of substituents X, Y and Z for the reaction of (Z)-substituted benzyl (X)-benzenesulphonates with (Y)-substituted N,N-dimethylanilines in aceton at 35 deg C.The coefficient of the interaction term, ρXY, has a value of 0.21 which means that bond-making and -breaking are concerted in the SN2 transition state.In the range Z = H to p-NO2, in which the SN2 mechanism is predicted to be dominant, the ρZY value is very large, 0.5, which means that the interaction between Z and Y is very large. ρZX is ca. 0.06 which means that the interaction is small between X and Z.In contrast, in the range Z = H to p-Me, in which the SN1 mechanism is dominant, the ρZY value is nearly zero, indicating no interaction between Z and Y.Changes of substituent effect and interaction terms, ρXY, ρYZ and ρZX are useful tools for distinguishing wrong reaction mechanisms.
- Yoh, Soo-Dong,Tsuno, Yuho,Fujio, Mizue,Sawada, Masami,Yukawa, Yasuhide
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- KINETICS AND MECHANISM OF HYDROLYSIS OF AROMATIC SULFONYL CHLORIDES IN AQUEOUS SULFURIC ACID SOLUTIONS
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The kinetics of the hydrolysis of 12 aromatic sulfonyl chlorides were studied by a spectrophotometric method in water and aqueous sulfuric acid solutions ( 1.0 - 60.5 wt.percent ) at 25 deg C and in 50percent sulfuric acid at several temperatures.It was shown that the reaction obeys the single-parameter equation log keff = log k0 + m'X, in which keff and k0 are the first-order rate constants in a solution with "excess acidity" X and in water respectively.The coefficient m' depends on the substituent in the ring and is equal to -0.85 to -0.38.The activity of the water does not enter into the equation for the calculation of keff.For the hydrolysis of nine substituted sulfonyl chlorides in 50percent sulfuric acid a satisfactory correlation is observed between log keff and the Σ?0.Palm induction constants ( ρ = -1.85 +/- 0.12 ).A reaction mechanism is proposed in which the rate-determining stage in the hydrolysis of the ArSO2Cl is the transformation of the complex H2O...SO2(Cl)Ar, in the form of which all the sulfonyl chloride dissolved in the water is present, into the reaction products.
- Gnedin, B. G.,Ivanov, S. N.,Shchukina, M. V.
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p. 731 - 737
(2007/10/02)
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- Sulfonation and sulfation in reactions of C-methylated phenols and anisoles with sulfur trioxide. 4-Substituted phenyl hydrogen sulfates: effective reagents for transsulfonation
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The sulfation and sulfonation of the methyl- and dimethylphenols with 0.9 and 4.0 equiv. of SO3 in nitromethane at 0 deg C have been studied.On using 0.9 equiv. of SO3, the sulfonic acid product distributions are determined by the ortho- and para-directing effect of the activating hydroxy substituent.In the reactions with 4.0 equiv. of SO3, the sulfonic acid product distributions are affected by the predominant initial formation and the subsequent sulfonation of the corresponding phenyl hydrogen sulfates, of which the bulky OSO3H substituent is electronically deactivating and (mainly) para-directing.For comparison, the sulfonation of the methylanisoles, phenyl methanesulfonate and 2,3-dihydrobenzofuran was also studied.The sulfonation of 1,3-dimethoxybenzene in (2H8)dioxane at 17.0 deg C has been studied using 4-substituted phenyl hydrogen sulfates as transsulfonating agents.The transsulfonation was found to be first order with respect to the phenyl hydrogen sulfates and independent of the 1,3-dimethoxybenzene concentration.The reaction constant of the transsulfonation reaction was determined to be ρ=2.0+/-0.2.
- Goossens, Hans D.,Lambrechts, Hans J. A.,Cerfontain, Hans,Wit, Peter de
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p. 426 - 430
(2007/10/02)
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- Aromatic Sulphonation. Part 91. The Sulphonation of Anisole, Phenol, Phenyl Methanesulphonate, Potassium Phenyl Sulphate, and a Series of Methyl-, Bromo-, and Chloro-substituted Anisoles and Phenols in Concentrated Aqueous Sulphuric Acid
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The (homogeneous) sulphonation of a number of aromatic ethers and alcohols, viz. anisole (1), 3-methyl- (2), 4-methyl- (3), 2-bromo- (4), 4-bromo- (5), 2-chloro- (6), and 4-chloro-anisole (7), phenol (8), 2-methyl- (9), 3-methyl- (10), 4-methyl- (11), 4-bromo- (12), 2-chloro- (13), and 4-chloro-phenol (14), phenyl methanesulphonate (15), and potassium phenyl sulphate (16) in concentrated aqueous sulphuric acid at 25.0 deg C has been studied, and rates and isomer distributions have been determined.The sulphonation is first-order in the aromatic substrate, and from the rate measurements it is concluded that the species undergoing sulphonation in the phenyl ring is an unprotonated substrate species.In the lower acid concentrations the sulphonating entity is H3SO4(1+).With increasing sulphuric acid concentration there is a gradual change-over in the sulphonating entity from H3SO4(1+) to H2S2O7.The acid concentrations of equal rate contribution by the two entities for anisole and phenol are 87 and 90 +/- 1percent, respectively.Sulphonation on the oxygen atom (i.e., sulphation) does not occur.The o/p-ratios for (1) and (8) do not vary over the studied sulphuric acid range of 75-90percent H2SO4.Partial rate factors for the 2- and 4-position of (1) and (8) are reported.The very low partial rate factors for the 4-substitution of (1) and (8) and the observed extreme suppression and compression of the reactivities of the substrates (1)-(14) are ascribed to hydrogen bonding of the substrates with the acidic solvent species present.It is tentatively suggested that the relatively high contents of sulphonation ortho to -OR with anisole (36percent) and phenol (48percent) are due to specific complexation of the substrates with the sulphonating electrophile.
- Cerfontain, Hans,Lambrechts, Hans J. A.,Schaasberg-Nienhuis, Zwaan R. H.,Coombes, Robert G.,Hadjigeorgiou, Panicos,Tucker, Geoffrey
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p. 659 - 668
(2007/10/02)
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- EFFECT OF STRUCTURE ON THE KINETICS AND MECHANISM OF THE ACID-CATALYZED DECOMPOSITION OF N-ALKYL-N-NITROBENZENESULFONAMIDES
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The decomposition rate of a series of meta- and para-substituted N-alkyl-N-nitrobenzenesufonamides was determined by a spectrophotometric method in aqueous sulfuric acid.It was shown that the decomposition of the compounds takes place both by denitration and by cleavage of the N-S bond with the formation fo primary aliphatic N-nitrosamines.Electron-withdrawing substituents in the aromatic ring shift the process toward denitration.
- Drozdova, O. A.,Astrat'ev, A. A.,Kuznetsov, L. L.,Selivanov, V. F.
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p. 671 - 675
(2007/10/02)
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- COMPARISON OF THE MECHANISMS OF SOLVOLYSIS OF ARENESULFONIC ESTERS OF BEZOIN IN METHANOL AND FORMIC ACID ON THE BASIS OF THE HAMMOND POSTULATE
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The kinetic of the methanolysis of the arenesulfonic esters of substituted benzoins p-XC6H4C(O)CH(OSO2C6H4Y)C6H5 (X = CH3O, H, Cl; Y = p-CH3O, p-CH3, H, p-Cl, m-Cl) at 30-50 deg C were studied, and it was established that unlike the previously investigated formolysis of these substrates (ρ+X o and ρY is opposite in character, which agrees with the Hammond postulate.The given contradiction is explained by the fact that the experimental temperature range is higher than the isoselectivity temperature.
- Dement'eva, L. P.,Semenova, S. N.,Karavan, V. S.
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p. 654 - 657
(2007/10/02)
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- STUDIEN ZUM VORGANG DER WASSERSTOFFUEBERTRAGUNG.61. Chemische Reaktivitaet und Halbstufenpotential Vergleichende Versuche am Beispiel einiger Arylsulfonsaeurederivate
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In arylsulfonyl halides, the half-wave potentials of the corresponding chlorides and fluorides differ by more than 1000 mV, the fluoride being more negative; the influence of para-substituents is small for the chlorides, large for the fluorides.In agreement with the half-wave potentials, arylsulfonyl chlorides are considerably more reactive chemically than the corresponding fluorides.The O-selectivity found for P(O)F compounds is not observed in arylsulfonyl fluorides.Studies of competitive ester formation using primary and secondary alcohols and various arylsulfonyl chlorides yielded no clear analogy to the half-wave potentials.The primary alcohol is always sulfonated in preference to the secondary alcohol, whether the hydroxy functions are present in different molecules or the same molecule.In the latter case, the secondary hydroxyl function is then attacked in a further step by a second, different, arylsulfonyl chloride, giving the compounds 4-8.The further electroreduction of these diesters may be carried out in high yields, giving selective fission of one ester linkage only (that with the more positive potential) provided the difference in the half-wave potentials of the different ester linkages is sufficiently large.In the electroreductive fission the monosulfinic acid and the corresponding alcohol are liberated (see table II).In the competition reaction between phenol and 1:1 mixtures of tosyl chloride (A) and p-carboxyethyl-benzenesulfonyl chloride (B), the chloride with the more positive potential (B), E1/2=72 mV reacts quicker by a factor of 2.5.In competitive Finkelstein reactions, the selectivity was 1:11 at a difference in half-wave potentials of 760 mV (table IV).Arylsulfonates with free secondary alcohol functions may be oxidized smoothly and in high yield to the corresponding ketone using Na2Cr2O7 (3), without effecting the sulfonate linkage.The alkali hydrolysis of n-hexyl para-substituted arylsulfonates follows the Hammett relation but shows a lesser selectivity than was observed in the electroreductive fission of the same esters at the required potentials.Tables VI, VII and VIII concentrate on the preparative importance of the potential-controlled electroreductive fission of aliphatic and aromatic arylsulfonates.The corresponding hydroxy compounds are liberated in yields of up to over 90percent: N-alkyl- and N-aryl arylsulfonamides give analogous results. (table IX)
- Horner, Leopold,Schmitt, Rolf-Erhard
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p. 189 - 212
(2007/10/02)
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- PHOTOCHEMICAL SUBSTITUTION OF HALOGEN AND SO2X GROUPS BY THIOUREA AND THIOSEMICARBAZIDE. PHOTOSYNTHESIS OF AROMATIC DISULFIDES
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During UV irradiation in the presence of thiourea (or thiosemicarbazide) the para- and ortho-halogen and sulfonyl derivatives of the benzene, naphthalene, and heterocyclic series with donating substituents in the ring are converted into arylisothiuronium salts.Thermal hydrolysis and oxidation of these salts lead to the formation of the respective diaryl disulfides in the case of the para isomers and thiazoles for the ortho isomers.
- Frolov, A. N.,Klokova, E. M.,El'tsov, A. V.
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p. 1926 - 1935
(2007/10/02)
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- Le sulfate de bis (trimethylsilyle) reactif de sulfonation en chimie organique
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Trimethylsilyl chlorosulphonate 1 and di-(trimethylsilyl) sulphate 2 are obtained by reacting trimethylchlorosilane with chlorosulphonic acid and sulphuric acid respectively. 1 and 2 are thermally stable and soluble in most of the organic solvents.The silyl sulphonates are hydrolyzed at room temperature. 2 is less reactive than 1 and is adequate reagent when the molecule contains ether or ester groups as 1 reacts also as chlorination reagent.Thus, 2 when refluxed in the presence of an excess of methoxy benzene gives quantitatively trimethylsilyl 4-methoxybenzenesulphonate 3 which is hydrolyzed quantitatively into 4-methoxybenzenesulphonic acid. 2 reacts with acid chlorides and acid anhydrides in refluxing cyclohexane or carbon tetrachloride which leads to α-sulphonic carboxylic acids 4 by sulphonation in position α to the acyl function.When starting from chloroacetylchloride, a gem-disulphonic derivative 5 is formed.A common intermediate, acyl and trimethylsilyl sulphate 6, is put forward and easy preparation and isolation of sulphonic acids by this method is pointed out.
- Bourgeois, Paul,Duffaut, Norbert
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p. 195 - 199
(2007/10/02)
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