- A simple method for the synthesis of sulfonic esters
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An efficient and simple approach for the direct synthesis of aryl and heteroaryl sulfonic esters was developed using DMS and DES as alkoxysulfonylation reagents. The reaction is operationally simple and scalable. This protocol does not require solvent, expensive catalysts, base, ligand additives or other reagents. A wide range of sulfonic esters were synthesized in moderate to good chemical yields. This method has the advantage of low cost, facile and tolerated a wide range of substrates.
- Bhatthula, Bharath Kumar Goud,Kanchani, Janardhan Reddy,Arava, Veera Reddy,Marata Chenna Subbarao, Subha
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supporting information
p. 1 - 16
(2020/07/27)
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- Electrochemical synthesis of sulfinic esters from alcohols and thiophenols
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Electrochemical oxidative couplings between S[sbnd]H and O[sbnd]H bonds are achieved herein directly from readily-available alcohols and thiophenols, affording a series of diverse sulfinic esters. This strategy can take advantage of 6 equivalents of alcohol, relative to thiophenol, to achieve moderate to good yields, without the assistance of any metallic catalysts, bases, and additional oxidants.
- He, Yang,Zhang, Jinli,Xu, Liang,Wei, Yu
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supporting information
(2020/01/31)
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- Copper-Catalyzed Multicomponent Reaction of DABCO·(SO2)2, Alcohols, and Aryl Diazoniums for the Synthesis of Sulfonic Esters
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A Cu-catalyzed multicomponent cascade reaction of DABCO·(SO2)2 (DABSO), alcohol, and aryl diazonium tetrafluoroborate was developed which afforded sulfonic esters in moderate to good chemical yields. In this reaction, the SO2 surrogate DABSO was used for the first time in the synthesis of sulfonic aliphatic esters. This multicomponent reaction was carried out under mild conditions and tolerated a wide range of substrates, which provides a new and efficient strategy for the synthesis of sulfonic esters.
- Wang, Yang,Deng, Lingling,Deng, Yu,Han, Jianlin
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p. 4674 - 4680
(2018/04/26)
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- Generation of VBr? VBi? VO?? defect clusters for 1O2 production for molecular oxygen activation in photocatalysis
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Defect engineering on a semiconductor surface can provide coordinatively unsaturated sites for molecular oxygen activation in photocatalysis. In this work, we demonstrated that the vacancy type was key to modulate the molecular oxygen activation process on BiOBr nanosheets. By regulating the reaction time, an oxygen vacancy (VO??), a double atom defect cluster (VBi? VO??) and triple atom clusters (VBi? VO?? VBi? and VBr? VBi? VO??) were accordingly generated on the surface, subsurface and bulk of BiOBr. More importantly, the newly-discovered VBr? VBi? VO?? defect cluster was highly related to the singlet oxygen (1O2) production ability of BiOBr. Meanwhile, the excellent photocatalytic selective oxidation reactions were successfully realized over BiOBr with the VBr? VBi? VO?? defect cluster. In addition, time-dependent defect cluster generation and the associated molecular oxygen activation were discussed.
- Ding, Jie,Dai, Zan,Tian, Fan,Zhou, Bo,Zhao, Bin,Zhao, Huiping,Chen, Zhiquan,Liu, Yunling,Chen, Rong
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supporting information
p. 23453 - 23459
(2017/11/30)
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- HIGHLY PURE SALTS OF CLOPIDOGREL FREE OF GENOTOXIC IMPURITIES
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The present invention relates to substantially pure salts of clopidogrel of Formula (I) substantially free from genotoxic impurities. (I) wherein (S) represents a suitable organic or inorganic acid, which forms a salt with clopidogrel having less acidity.
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Page/Page column 15-16
(2012/10/07)
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- CsF-Celite as an efficient heterogeneous catalyst for sulfonylation and desulfonylation of heteroatoms
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CsF-Celite is found to be as an efficient reusable catalyst for sulfonylation and desulfonylation of heteroatoms. Sulfonamides and N-acylsulfonamides deprotect efficiently in the presence of CsF-Celite under solvent free conditions to give the free amines or amides in good to excellent yields.
- Tamaddon, Fatemeh,Nasiri, Alireza,Farokhi, Somayeh
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experimental part
p. 1477 - 1482
(2012/06/18)
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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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- The Hammett equation and micellar effects on SN2 reactions of methyl benzenesulfonates - The role of micellar polarity
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Substituent effects on the reaction of H2O, OH-, and Br- with p-substituted methyl benzenesulfonates in cationic micelles of cetyl trialkylammonium ion surfactants (n-C16H33NR3X, X = OH, Br, R = Me, Et, nPr, nBu) and in water were analyzed by using the Hammett equation. Values of p in the various media confirm that micellar interfacial regions are less polar than water and polarities decrease with increasing bulk of the surfactant head-group. Wiley-VCH Verlag GmbH, 2000.
- Brinchi, Lucia,Di Profio, Pietro,Germani, Raimondo,Savelli, Gianfranco,Spreti, Nicoletta,Bunton, Clifford A.
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p. 3849 - 3854
(2007/10/03)
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- Process for preparation of oxyglutaric acid ester derivatives
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A process for preparing an oxyglutaric acid ester derivative of the formula: STR1 in which each of R1 and R2 is C1-5 alkoxy, C1-7 aralkyloxy, C7-9 halogenated aralkyloxy or phenyl, R4 is a hydroxyl-protecting group, and R5 is C1-10 alkyl which may have a substituent, comprises the steps of reacting a methyl phosphonate derivative or methyl phosphine oxide derivative with an oxyglutaric acid mono-ester to give a reaction product which comprises an oxyglutaric acid derivative having a phosphorus-containing group and a pentenedioic acid mono-ester (by-product), removing the pendenedioic acid mono-ester from the reaction product to isolate the oxyglutaric acid derivative, and converting the isolated oxyglutaric acid derivative into the oxyglutaric acid ester derivative. A process for obtaining an optically active oxyglutaric acid ester derivative is also disclosed.
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- Solvolysis of benzenesulfonyl chloride. Base and nucleophilic catalysis mechanisms with tertiary amines
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Competing pathways in the phenolysis and methanolysis of benzenesulfonyl chloride in acetonitrile, catalyzed by tertiary amines, have been distinguished. The rate of the reaction pathway, where nucleophilic catalysis is operative, is strongly sensitive to inductive and steric effects of substituents in the tertiary amine and almost insensitive to the nature of the nucleophile. The rate of the general base catalysis pathway is very sensitive to nucleophilic power of the amine and nucleophile and almost insensitive to steric accessibility of the catalyst. 1996 MAEe Cyrillic signΚ Hayκa/Interperiodica Publishing.
- Bezrodnyi,Kiprya,Skrypnik
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p. 519 - 523
(2007/10/03)
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- Bimolecular Nucleophilic Substitution (SN2) Reactions of Neopentyl Arenesulfonates with Anilines and Benzylamines in Methanol
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Bimolecular nucleophilic substitution (SN2) reactions of neopentyl arenesulfonates with anilines and benzylamines in methanol at 55.0 deg C are reported.The tightness of the transition state (TS) is similar to that for other typical SN2 processes at a primary alkyl carbon centre based on the magnitude of the cross-interaction constant ρxz (0.30) between the substituents in the nucleophile (X) and leaving group (Z).The TS variation is in accord with that predicted by the potential energy surface diagram, which in turn is consistent with the positive sign of ρxz; a later TS is obtained with a weaker nucleophile and nucleofuge.Taft's polar substituent constant, ?*, for the trimethylsilyl group is estimated to be -0.48 by using a factor of 1.875 for the fall-off of ?* from the tert-butyl to the neopentyl group and extrapolating from the experimental Taft plot.
- Koh, Han Joong,Lee, Hai Whang,Lee, Ikchoon
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p. 253 - 258
(2007/10/02)
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- Preparation and photolysis of diaryl esters of acetylenedicarboxylic acid
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Two diaryl acetylenedicarboxylates 1 a,b have been prepared in moderate yields by direct reaction of acetylenedicarboxylic acid with the corresponding phenols catalyzed by sulfuric or p-toluenesulfonic acids and also through acetylenedicarbonyl chloride. The accompanying by-products have been characterized. Attempted esterification using N,N'-dicyclohexylcarbodiimide as condensing agent gives an asymmetric ester amide 11a and a substituted uracil 12a. Photolysis of the aryl ester 1 a,b in benzene solution affords the benzocoumaran-3-ones 14 a,b. In the case of 1b, minor amounts of a polycyclic condensed 4-chromanone 17b have also been observed. These results show that the nature of the substituent attached at the β-position of the C ≡ C triple bond plays an important role in the cyclization of o-hydroxyaryl ethynyl ketones.
- Alvaro,Garcia,Miranda,Primo
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p. 3437 - 3444
(2007/10/02)
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- THE OXIDATION OF TRITHIOCYANURIC ACID AND OF ITS N- AND S-ESTERS
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The reaction of trithiocyanuric acid 1 with 3 equivalents of 2-benzenesulfonyl-3-phenyl-oxaziridine affords the highly reactive 1,3,5-triazine-2,4,6-trisulfenic acid 3, which is trapped by reaction with diazomethane to give the trimethylester of 3.Additionally the reactions of trithioisocyanurates and trithiocyanurates with meta-chloroperbenzoic acid (mCPBA), oxaziridine, dimethyldioxirane and chlorine are studied.
- Tripolt, Robert,Nachbaur, Edgar
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p. 173 - 176
(2007/10/02)
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- Micellar Effects upon the Rates of SN2 Reactions of Halide Ions
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Observed first-order rate constants for reactions of Cl- or Br- with alkyl benzenesulfonate (1a-c) in micelles of cetyltrimethylammonium surfactants (CTAX, X=Cl, Br, OMes, 0.5SO4) increase monotonically with increasing or or halide ion concentration and tend to limiting values.In CTAOMes or (CTA)2SO4, the rate constants go through maxima.The variation of the rate constants with concentrations of surfactant and halide ion can be fitted to an equation that accounts for the distribution of both reactants between water and micelles, i. e., in terms of ion-exchange and mass-action models.The second-order rate constants in the aqueous and micellar pseudophases are similar.
- Al-Lohedan, Hamad A.
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p. 8226 - 8231
(2007/10/02)
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- Mesylhydroxylamines, VI. Oxidation of N-Mesylhydroxylamines - Vibrational Spectra and Structure of 1,2-Dimesyl-1,2-dimethoxyhydrazine
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The oxidation reactions of mesylhydroxylamines proceed mainly via radicals.Oxidation of CH3SO2N(H)OH gives trimesylhydroxylamine (5) probably via the intermediate CH3SO2NO (4).By oxidizing CH3SO2N(H)OCH3 and C6H5SO2N(H)OCH3, derivatives of the hypothetical dihydroxyhydrazine were formed (7a,b).Thermolysis leads to dinitrogen and methyl sulfonate.Oxidation of (CH3SO2)2NOH (1) also gives 5, via 4, but the isomeric CH3SO2N(H)OSO2CH3 is oxidized to nitrate.According to an X-ray structure analysis, 1,2-dimesyl-1,2-dimethoxyhydrazine (7a) crystallizes in the space group P21/n with pyramidally coordinated nitrogen atoms.The vibrational spectra and the structure were discussed in relation to other mesylated nitrogen compounds.
- Brink, Klaus,Mattes, Rainer
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p. 564 - 573
(2007/10/02)
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- Methyl Transfers. 8. The Marcus Equation and Transfer between Arenesulfonates
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Using a 35S label, rates of identity methyl-transfer reactions XC6H4*SO3(1-) + CH3O3SC6H4X -> XC6H4*SO3CH3 + XC6H4SO3(1-) in sulfolane have been measured.For all five cases, these identity rates fit the Hammett equation with the rather large ρ of +0.6.Rates and equilibria for XC6H5SO3Me + 3,4-Cl2C6H3SO3(1-) have been measured.The fit to the Marcus equation using averages of the experimental identity rates for the intrinsic rate is perfect, within experimental error.The absolute values of ρ for the forward and reverse reactions differ by an amount quantitatively consistent with the nonzero identity reaction ρ.The significance of the identity reaction ρ > 0 is discussed.
- Lewis, Edward S.,Hu, Daniel D.
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p. 3292 - 3296
(2007/10/02)
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- Electrogenerated Bases. VI. Reaction of Electrogenerated Superoxide with Some Carbon Acids. II.
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Electrogenerated superoxide and molecular oxygen were allowed to react sequentially with a number of esters, nitriles, N,N-dialkylamides, sulfones, and aliphatic nitro compounds.The α-methyl groups in these compounds bore aliphatic and/or aromatic substituents.When the electron-withdrawing group (EWG) of these carbon acids could be displaced intact (nitile 2, ArSO2 4, nitro) good to excellent yields of the corresponding carbonyl compounds could be obtained.The efficiency of the transformation depended upon the nature of the substituents: α,α-diphenyl (e.g., 2a) > α-methyl-α-phenyl (2b) > α,α-dimethyl.By conducting the electrolysis in the presence of acetic anhydride it was shown that the known conversion of phenylacetonitrile (2d) to benzoic acid did indeed proceed via benzaldehyde.When the EWG itself could be cleaved (esters 1, N,N-dialkyl-amides 3), this methodology produced α-hydroxylated compounds and the products resulting from fragmentation of the EWG and also from its complete displacement.The effects of the α-substituents were similar to those above.
- Sugawara, M.,Baizer, M. M.,Monte, W. T.,Little, R. D.,Hess, U.
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p. 509 - 518
(2007/10/02)
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- Methyl-Transfer Reactions. 6. Arenesulfonates as Nucleophiles and Leaving Groups. Methyl Trinitrobenzenesulfonate
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The methyl-transfer reactions from several substituted methyl arenesulfonates to potassium benzenesulfonate in sulfolane have been studied with respect to both rates and equilibria.Because the reactions were followed by proton NMR of the methoxy group, only cases of methyl arenesulfonates with quite distinct methoxy chemical shifts from the unsubstituted ester could be studied, and this, in fact, required the use of ortho substituents.Hammett plots for these data were thus impossible, but a plot of log k+ vs. log K, although somewhat scattered, did allow an estimation of the rate of the identity reaction for the unsubstituted compound.These methyl arenesulfonates, as well as methyl iodide, were placed roughly on the scale of equilibrium methylating agents studied earlier in the same solvent.Methyl 2,4,6-trinitrobenzenesulfonate is a very reactive substance not compatible with sulfolane.It is soluble and stable only in thionyl chloride among a large number of solvents attempted and methylates a few weak nucleophiles more extensively than methyl trifluoromethanesulfonate.
- Lewis, Edward S.,Smith, Michael J.,Christie, J. Joseph
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p. 2527 - 2531
(2007/10/02)
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- 2,2-Bis(ethylthio)ethanenitrile: preparation and use as a one or two carbon nucleophile
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2,2-Bis(ethylthio)ethanenitrile 1 was prepared in high yield from 2,2-bis(ethylthio)ethanal 2.Alkylation of the potassium salt of 1 with various alkylating agents and conjugate addition to cyclic α,β-unsaturated ketones provided high yields of the alkylation products of 1.The potential one and two carbon chain extension capability of this new reagent has been demonstrated.
- Bates, Gordon S.,Ramaswamy, S.
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p. 2006 - 2009
(2007/10/02)
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- Enamines of 2,2-bis(ethylthio)ethanal: a convenient route to γ-keto crotonate derivatives
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A new α-oxoaldehyde reagent, 2,2-bis(ethylthio)ethanal 1, has been prepared in high yield from ethanedial.Alkylation of the potassium salt of the enamines of 1 with various alkylating agents followed by in situ hydrolysis of the intermediate imine afforded high yields of the alkylation products of 1.This new reagent was used in the synthesis of a chiral potential precursor of the macrocyclic fragment of cytochalasins A,B, and F, as well as in the syntheses of the physiologically active diolides pyrenophorin and norpyrenophorin.
- Bates, Gordon S.,Ramaswamy, S.
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p. 2466 - 2475
(2007/10/02)
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- Intramolecular Reactions. Part 12. Ring Size and Leaving Group Effects on Inter- and Intra-molecular Nucleophilic Substitution by Carbanions
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In cyclisations of aryl ο-halogenoalkyl ketones to aryl cycloalkyl ketones with base, cyclopropanes are formed up to 23000 times faster than cyclopentanes.Hydrogen-deuterium exchange experiments and very low bromide-chloride ratios (1.9) for three-membered ring formation are consistent with rate-determining deprotonation of the ketone.By contrast, in five-membered ring formation, hydrogen-deuterium exchange adjacent to the carbonyl group occurs much faster than cyclisation and the chloride-bromide ratio is 'normal' at 99.In formation of arylsulphonylcyclopropanes from arylsulphonylpropyl arenesulphonates, the Hammett ρ value for the leaving group is +1.7, and for intermolecular substitution by bis-sulphonyl stabilised carbanions, +1.2.Attempts to obtain ρLG values for five-membered ring formation were frustrated by competing intermolecular reactions.The results are discussed against the background of previous work on ring formation by intramolecular nucleophilic substitution.
- Bird, Roger,Griffiths, Gwerydd,Griffiths, Gwynfor F.,Stirling, Charles J. M.
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p. 579 - 584
(2007/10/02)
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- Nucleophilic Substitution at Sulphonyl Sulphur. Part 2. Hydrolysis and Alcoholysis of Aromatic Sulphonyl Chlorides
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Kinetics of hydrolysis, methanolysis and ethanolysis of furan-2 and -3-, thiophen-2- and -3-, and benzene-sulphonyl chlorides have been measured.Fair correlations with Taft ?* values for heterocycles are found; more satisfactory trends are observed by applying the two-parameter (polar and steric) Taft-Pavelich equation, particularly for the hydrolysis reaction including data for aliphatic sulphonyl chlorides.In this case the negative δ value, which is related to the steric parameter, is consistent with steric acceleration due to relief of strain in the transition state.Alcoholysis rates of substituted thiophen-2-sulphonyl chlorides (5-CH3, 5-Cl, 4-NO2, and 5-NO2) have been also measured in order to compare the substituent effects with those already observed for hydrolysis.The data are in accord with previous findings, that an SN2 type mechanism takes place which is shifted toward an SN1 process (looser transition state) or an SAN process (tighter transition state) in the hydrolysis and alcoholysis reactions, respectively.
- Ballistreri, Francesco P.,Cantone, ALfio,Maccarone, Emanuele,Tomaselli, Gaetano A.,Tripolone, Mario
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p. 438 - 441
(2007/10/02)
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- Perchlorate Esters. Part 3. Correlation of the Rates of Reaction of Arenesulphonate Ions with Methyl Perchlorate in Acetonitrile
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Second-order rate coefficients for the reactions of acetonitrile solutions of tetra-n-butylammonium benzensulphonate and seven meta- and para-substituted derivatives with methyl perchlorate, at 0.3 deg C lead to a Hammet ρ value (-1.10 +/- 0.04) essentially identical to those previously reported for reactions with other powerful methylating agents.When silver ion is substituted for tetra-n-butylammonium ion, the second-oreder rate coefficients become concetration dependent and the fall of with increasing salt concetration can be rationalised on the basis of only free anions being reactive.The calculated degrees of dissociation are applied tothe previously studied silver0ion assisted reaction of silver toluene-p-sulphonate with methyl iodide.
- Kevill, Dennis N.,Lin, Gloria Meichia L.,Bahari, Mohd S.
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- CORRELATION OF THE RATES OF REACTION OF ARENESULFONATE IONS WITH THE TRIMETHYLOXONIUM ION IN ACETONITRILE
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The kinetics of the reactions between trimethyloxonium hexafluorophosphate and a series of tetra-n-butylammonium arenesulfonates have been studied in acetonitrile at -23.4 deg C.With the oxonium salt concentration at about 0.01 M, two series of runs were carried out; Hammett plots of the second-order rate coefficients led to ρ values of -1.18 +/- 0.04 for 0.04 M arenesulfonate salt and -1.07 +/- 0.02 for 0.16 M arenesulfonate salt.Solvolysis kinetics for the trimethyloxonium ion in acetonitrile are also reported.
- Kevill, Dennis N.,Lin, Gloria Meichia L.,Wang, An
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p. 715 - 717
(2007/10/02)
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- Benz (c) fluoran compounds and recording sheet containing them
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Novel benz[c]fluoran compounds such as 2-phenylamino-8-diethylamino-benz[c]fluoran, 2-(2',4',6'-trimethylphenylamino)-8-diethylamino-benz[c]fluoran and N-[8-diethylaminobenz[c]fluoran-2-yl]-N-[6-diethylaminofluoran-2-yl]amine, which are useful as a coloring material for record material systems such as pressure-sensitive copying paper or heat-sensitive copying paper, wherein colored images formed by an electron-donoracceptor color-forming reaction between coloring material and acidic material.
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- Benzo-1,2,4-triazines
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Benzo-1,2,4-triazines-1,4-di-N-oxides substituted in the 3-position with a substituted amino group and optionally substituted in the benzo ring are antimicrobial agents. The compounds, of which 3-(N-acetoacetylamino)benzo-1,2,4-triazine-1,4-di-N-oxide is a typical embodiment, are prepared from the corresponding 2-aminobenzo-1,2,4-triazine-1,4-di-N-oxide through alkylation or acylation.
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- Chromogenic compounds and method for preparation thereof
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Chromogenic compounds for use in pressure sensitive recording sheets represented by the formula: SPC1 Are disclosed, wherein R1 and R2 are independently, hydrogen substituted or unsubstituted lower alkyl, aliphatic acyl, phenyl substituted aliphatic acyl, benzoyl, aralky, phenyl (the benzene nuclei of those substituents may be further substituted by chlorine, bromine, lower alkyl, lower alkoxy or nitro), allyl, allyl substituted by lower alkyl or phenyl, propargyl, or propargyl substituted by lower alkyl or a phenyl; R3 and R4 are independently lower alkyl, benzyl and phenyl (the benzene nuclei or those substiutents may be further substituted by chlorine, bromine, lower alkyl or lower alkoxy), either R1 or R2 being other than hydrogen when R3 and R4 are both ethyl groups.
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