- Indium-catalysed aryl and alkyl sulfonylation of aromatics
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Commercially available indium (III) triflate is shown to be an extremely efficient catalyst for the sulfonylation of both activated and deactivated aromatics.
- Frost,Hartley,Whittle
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- Study of regioselective methanesulfonylation of simple aromatics with methanesulfonic anhydride in the presence of zeolite catalysts
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Regioselective methanesulfonylation of simple aromatics using methanesulfonic anhydride can be achieved over zeolite catalysts. For example, methanesulfonylation of toluene over various cation-exchanged zeolite β catalysts affords higher para-selectivity in the synthesis of methyl tolyl sulfone than standard Friedel Crafts methanesulfonylation utilising aluminium chloride.
- Smith, Keith,Ewart, Gordon M.,El-Hiti, Gamal A.,Randles, Kenneth R.
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- Regioselective methanesulfonylation of toluene catalysed by cation-exchanged zeolite β
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The reaction of methanesulfonic anhydride with toluene over various cation exchanged zeolite beta catalysts affords higher para-selectivity and better yields of methyl tolyl sulfone than standard Friedel-Crafts sulfonylation utilising aluminium chloride.
- Smith, Keith,Ewart, Gordon M.,Randles, Kenneth R.
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- Friedel-Crafts sulfonylation of aromatics catalysed by solid acids: An eco-friendly route for sulfone synthesis
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A mild and efficient catalytic method for Friedel-Crafts sulfonylation of arenes to the corresponding sulfones using a catalytic amount of reusable solid acid and arene- or alkanesulfonyl chlorides, sulfonic anhydrides and sulfonic acids as sulfonylating agents is described. Solid acids enable formation of a sulfone by the reaction of a sulfonic acid and an arene for the first time. In pursuit of the development of the best catalytic system, various metal-exchanged K10 montmorillonites and synthetic zeolites such as zeolite beta, zeolite Y and ZSM-5 have been screened for Friedel-Crafts sulfone synthesis. Fe3+-montmorillonite in the family of clays and zeolite beta in the family of zeolites exhibit higher activity. The activity is correlated to the presence of the right mix of Bronsted and Lewis acidic sites. The regioselective sulfonylation of toluene and naphthalene are studied in which para and beta selectivities are observed respectively. The Royal Society of Chemistry 2000.
- Choudary, Boyapati M.,Chowdari, N. Sreenivasa,Kantam, M. Lakshmi
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- High Chemoselectivity in the Construction of Aryl Methyl Sulfones via an Unexpected C-S Bond Formation between Sulfonylhydrazides and Dimethyl Phosphite
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A highly chemoselective route to aryl methyl sulfones via an unexpected C S bond formation between sulfonylhydrazides and dimethyl phosphite catalyzed by NaI under mild conditions has been established. This transformation provides an alternative and metal-free pathway to acquire various aryl methyl sulfones in good to excellent yields. Notably, dimethyl phosphite was employed as a stable and readily available alkyl source.
- Liu, Teng,Yu, Shiwen,Shen, Xiang,Li, Yixian,Liu, Jianjun,Huang, Chao,Cheng, Feixiang
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p. 153 - 160
(2021/10/04)
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- Synergistic cooperative effect of CF3SO2Na and bis(2-butoxyethyl)ether towards selective oxygenation of sulfides with molecular oxygen under visible-light irradiation
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A safe, practical and eco-friendly method for the switchable synthesis of sulfoxides and sulfones through visible-light-initiated oxygenation of sulfides at ambient temperature under transition-metal-, additives-free and minimal solvent conditions. The synergistic catalytic efforts between CF3SO2Na and 2-butoxyethyl ether represents the key promoting factor for the reaction. This journal is
- Liu, Kai-Jian,Wang, Zheng,Lu, Ling-Hui,Chen, Jin-Yang,Zeng, Fei,Lin, Ying-Wu,Cao, Zhong,Yu, Xianyong,He, Wei-Min
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supporting information
p. 496 - 500
(2021/01/28)
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- Flow Electrosynthesis of Sulfoxides, Sulfones, and Sulfoximines without Supporting Electrolytes
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An efficient electrochemical flow process for the selective oxidation of sulfides to sulfoxides and sulfones and of sulfoxides toN-cyanosulfoximines has been developed. In total, 69 examples of sulfoxides, sulfones, andN-cyanosulfoximines have been synthesized in good to excellent yields and with high current efficiencies. The synthesis was assisted and facilitated through a supporting electrolyte-free, fully automated electrochemical protocol that highlights the advantages of flow electrolysis.
- Amri, Nasser,Wirth, Thomas
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p. 15961 - 15972
(2021/07/20)
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- Lifitegrast intermediate and preparation method thereof
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The invention relates to the field of pharmaceutical and chemical production, and discloses a lifitegrast intermediate and a preparation method thereof. A reaction route of the preparation method is as described in the specification. The preparation metho
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Paragraph 0031; 0047-0048
(2021/07/08)
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- Aryl Methyl Sulfone Construction from Eco-Friendly Inorganic Sulfur Dioxide and Methyl Reagents
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A three-component cross-coupling protocol of boronic acid, sodium metabisulfite, and dimethyl carbonate was developed for the construction of significant functional methyl sulfones, in which introduction of sulfur dioxide at the last stage was successfully achieved in one step. Inorganic sodium metabisulfite was used as an eco-friendly sulfur dioxide source. Green dimethyl carbonate was employed as methyl reagent in this transformation. Diverse functional methyl sulfones were obtained from various readily available boronic acids. Notably, the last-stage modification of pharmaceuticals and the synthesis of Firocoxib were efficiently established through this strategy.
- Wang, Ming,Zhao, Jiaoyan,Jiang, Xuefeng
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p. 3064 - 3068
(2019/02/19)
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- A novel synthesis of aryl methyl sulfones and β-hydroxysulfones from sodium sulfinates and di-tert-butyl peroxide in H2O medium
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A novel and convenient synthetic route for aryl methyl sulfones and β-hydroxysulfones was developed via the radical reaction between sodium sulfinates and di-tert-butyl peroxide (DTBP). Without any catalysts and additives, the synthetic process could be smoothly carried out to afford the target products in good to excellent yields in H2O medium, demonstrating its promising application. In the present system, H2O could act not only as a green solvent but also as a reactant.
- Lai, Junyi,Yuan, Gaoqing
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supporting information
p. 524 - 527
(2018/01/10)
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- A Class of Amide Ligands Enable Cu-Catalyzed Coupling of (Hetero)aryl Halides with Sulfinic Acid Salts under Mild Conditions
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The amide derived from 4-hydroxy-l-proline and 2,6-dimethylaniline is a powerful ligand for Cu-catalyzed coupling of (hetero)aryl halides with sulfinic acid salts, allowing the formation of a wide range of (hetero)aryl sulfones from the corresponding (hetero)aryl halides at considerably low catalytic loadings. The coupling of (hetero)aryl iodides and sodium methanesulfinate proceeds at room temperature with only 0.5 mol % CuI and ligand, representing the first example for Cu-catalyzed arylation at both low catalytic loading and room temperature.
- Zhao, Jinlong,Niu, Songtao,Jiang, Xi,Jiang, Yongwen,Zhang, Xiaojing,Sun, Tiemin,Ma, Dawei
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p. 6589 - 6599
(2018/05/31)
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- Electrophilic and nucleophilic pathways in ligand oxide mediated reactions of phenylsulfinylacetic acids with oxo(salen)chromium(V) complexes
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The mechanism of oxidative decarboxylation of phenylsulfinylacetic acids (PSAA) by oxo(salen)Cr(V)+ ion in the presence of ligand oxides has been studied spectrophotometrically in acetonitrile medium. Addition of ligand oxides (LO) causes a red shift in the λmax values of oxo(salen) complexes and an increase in absorbance with the concentration of LO along with a clear isobestic point. The reaction shows first-order dependence on oxo(salen)-chromium(V)+ ion and fractional-order dependence on PSAA and ligand oxide. Michaelis-Menten kinetics without kinetic saturation was observed for the reaction. The order of reactivity among the ligand oxides is picoline N-oxide > pyridine N-oxide > triphenylphosphine oxide. The low catalytic activity of TPPO was rationalized. Both electron-withdrawing and electron-donating substituents in the phenyl ring of PSAA facilitate the reaction rate. The Hammett plots are non-linear upward type with negative ρ value for electron-donating substituents, (ρ- = -0.740 to -4.10) and positive ρ value for electron-withdrawing substituents (ρ+ = +0.057 to +0.886). Non-linear Hammett plot is explained by two possible mechanistic scenarios, electrophilic and nucleophilic attack of oxo(salen)chromium(V)+-LO adduct on PSAA as the substituent in PSAA is changed from electron-donating to electron-withdrawing. The linearity in the log k vs. Eox plot confirms single-electron transfer (SET) mechanism for PSAAs with electron-donating substituents.
- Subramaniam,Sugirtha Devi,Anbarasan
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p. 164 - 173
(2016/06/06)
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- Dynamics of cetyltrimethylammonium bromide-mediated reaction of phenylsulfinylacetic acid with Cr(VI): Treatment of pseudo-phase models
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The influence of cetyltrimethylammonium bromide, CTAB, on the oxidative decarboxylation of phenylsulfinylacetic acid, PSAA, and several meta- and para-substituted PSAAs by Cr(VI) was investigated in 95 % H2O-5 % CH3CN medium. The rate profile displayed a peculiar trend with an initial rate increase at low CTAB followed by sharp rate inhibition at higher CTAB concentrations. The initial rate acceleration could be explained by strong binding of SO42- on the positively charged micellar surface. The specific partitioning of PSAA in the micellar phase by hydrophobic interaction and the oxidizing species HCrO3+ in aqueous phase by electrostatic repulsion accounted for the rate retardation at higher CTAB concentrations. The Hammett plot with different substituted PSAAs showed excellent correlation affording negative ? value, which supports the proposed mechanism involving the intermediate formation of sulfonium cation. The obtained ? value in CTAB medium was found to be slightly lower than that in aqueous medium. Quantitative analysis of the rate data for the inhibition shown by CTAB was performed using the Menger-Portnoy and the Piszkiewicz pseudo-phase models. The binding constant for PSAA with micelles was evaluated from the Piszkiewicz cooperative model.
- Subramaniam, Perumal,Selvi, Natesan Thamil
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p. 1019 - 1034
(2015/11/27)
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- Spectral and mechanistic investigation of Oxidative Decarboxylation of Phenylsulfinylacetic Acid by Cr(VI)
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The oxidative decarboxylation of phenylsulfinylacetic acid (PSAA) by Cr(VI) in 20% acetonitrile - 80% water (v/v) medium follows overall second order kinetics, first order each with respect to [PSAA] and [Cr(VI)] at constant [H+] and ionic strength. The reaction is acid catalysed, the order with respect to [H+] is unity and the active oxidizing species is found to be HCrO3+. The reaction mechanism involves the rate determining nucleophilic attack of sulfur atom of PSAA on chromium of HCrO3+ forming a sulfonium ion intermediate. The intermediate then undergoes a,β-cleavage leading to the liberation of CO2. The product of the reaction is found to be methyl phenyl sulfone. The operation of substituent effect shows that PSAA containing electron-releasing groups in the meta- and para-positions accelerate the reaction rate while electron withdrawing groups retard the rate. An excellent correlation is found to exist between log k2 and Hammett s constants with a negative value of reaction constant. The p value decreases with increase in temperature evidencing the high reactivity and low selectivity in the case of substituted PSAAs.
- Subramaniam, Perumal,Selvi, Natesan Thamil,Devi, Soundarapandian Sugirtha
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- Palladium-catalyzed sulfination of aryl and heteroaryl halides: Direct access to sulfones and sulfonamides
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A novel palladium-catalyzed sulfination of aryl and heteroaryl halides is described. This reaction operates under mild conditions and provides access to a wide range of aryl and heteroaryl sulfinates, a useful and versatile class of synthetic intermediates. Capitalizing on this sulfination reaction, one-pot protocols allowing direct access to sulfones and sulfonamides have also been developed. The practicality of these transformations is illustrated with the parallel synthesis of analogues of the drug Viagra.
- Shavnya, Andrei,Coffey, Steven B.,Smith, Aaron C.,Mascitti, Vincent
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supporting information
p. 6226 - 6229
(2014/01/17)
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- Copper-catalyzed aerobic oxidation and cleavage/formation of C-S bond: A novel synthesis of aryl methyl sulfones from aryl halides and DMSO
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With atmospheric oxygen as the oxidant, a novel copper(i)-catalyzed synthesis of aryl methyl sulfones from aryl halides and widely available DMSO is described. The procedure tolerates aryl halides with various functional groups (such as methoxy, acetyl, chloro, fluoro and nitro groups), which could afford aryl methyl sulfones in moderate to high yields. The copper-catalyzed aerobic oxidation and the cleavage/formation of C-S bond are the key steps for this transformation.
- Yuan, Gaoqing,Zheng, Junhua,Gao, Xiaofang,Li, Xianwei,Huang, Liangbin,Chen, Huoji,Jiang, Huanfeng
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supporting information; experimental part
p. 7513 - 7515
(2012/10/07)
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- Total Synergistic effect between triflic acid and bismuth(IIIr antimony(III) chlorides in catalysis of the Methanesulfonylation of Arenes
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A total synergistic effect between bismuth(III) or antimony(III) chlorides and triflic acid has been observed in the Friedel-Crafts methanesulfonylation of arenes and has resulted in the development of the first efficient catalytic systems usable for the methanesulfonylation of both activated and deactivated arenes. A proposed mechanism to explain the observed effects is also discussed. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Peyronneau, Magali,Boisdon, Marie-Therese,Roques, Nicolas,Mazieres, Stephane,Le Roux, Christophe
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p. 4636 - 4640
(2007/10/03)
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- Substituent effects in cooxidation: Cr(VI) - oxalic acid - sulfoxides systems
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The kinetics of cooxidation of several substituted phenyl methyl sulfoxides and oxalic acid with Cr(VI) have been carried out in the presence of perchloric acid.The reaction is first order each in sulfoxide, oxalic acid, Cr(VI), and H1+.The products of oxidation are sulfones and carbon dioxide.Electron-releasing groups in the phenyl ring accelerate the rate while electron-withdrawing groups retard it.The Hammett correlation yields a reaction constant of -0.927 +/- 0.08 (r = 0.994) at 313 K.Addition of aluminum nitrate prevents the occurence of cooxidation.Based on the kinetic information a suitable mechanism has been proposed.Diaryl sulfoxides behave in an analogous manner in the cooxidation.
- Srinivasan, C.,Jegatheesan, P. Pandarakutty,Rajagopal, S.,Arumugam, N.
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p. 2421 - 2424
(2007/10/02)
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- Mechanism of Oxidation of Aryl Methyl Sulphoxides and Diaryl Sulphoxides by Potassium Bromate
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The oxidation of aryl methyl and diaryl sulphoxides in aqueous acetic acid at constant and ionic strength is first order each in and .An excellent correlation exists between logk2 and the Hammett ? constants (ρ=-2.05, r=0.997, s=0.05, confidence limit on ρ=+/-0.10 in 50percent aq acetic acid (v/v) at 35 deg for aryl methyl sulphoxides and ρ=-1.82, r=0.992, s=0.12, confidence limit on ρ=+/-0.32 in 75percent aq acetic acid (v/v) at 35 deg for diaryl sulphoxides).The high negative ρ-value in the two series indicates considerable charge development in the transition state.
- Srinivasan, C.,Jegatheesan, P. Pandarakutty,Arumugam, N.
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p. 678 - 680
(2007/10/02)
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