cas 455-15-2, 4-FLUOROPHENYL METHYL SULFONE

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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
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
p. 153 - 160
(2021/10/04)

A mild and chemoselective CALB biocatalysed synthesis of sulfoxides exploiting the dual role of AcOEt as solvent and reagent
A mild, chemoselective and sustainable biocatalysed synthesis of sulfoxides has been developed exploiting CALB and using AcOEt with a dual role of more environmentally friendly reaction solvent and enzyme substrate. A series of sulfoxides, including the drug omeprazole, have been synthesised in high yields and with excellent E-factors.
Anselmi, Silvia,Liu, Siyu,Kim, Seong-Heun,Barry, Sarah M.,Moody, Thomas S.,Castagnolo, Daniele
supporting information
p. 156 - 161
(2021/01/14)

COVALENT ORGANIC FRAMEWORKS AND APPLICATIONS AS PHOTOCATALYSTS
Described herein are covalent organic frameworks. The covalent organic frameworks have unique structural and physical properties, which lends them to be versatile in a number of different applications and uses. In one aspect, the covalent organic frameworks are composed of a plurality of fused aromatic groups and electron-deficient chromophores. The covalent organic frameworks are useful as photocatalysts in a number of different applications.
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(2021/05/21)

NaHSO3-Mediated Direct Synthesis of Sulfinic Esters from Sulfonyl Hydrazides under Transition-Metal-Free Conditions
We have developed a protocol for the NaHSO3-promoted esterification of sulfonyl hydrazides with alcohols for the synthesis of sulfinic esters. Various sulfonyl hydrazides could be converted to the corresponding sulfinic esters in good to high yields. The merits of this protocol include mild transition-metal-free reaction conditions, an inexpensive and available reagent, and operational simplicity. Controlled experiments reveal that this transformation probably undergoes via a radical pathway. (Figure presented.).
Zhang, Guofu,Fan, Qiankun,Wang, Huimin,Zhao, Yiyong,Ding, Chengrong
p. 833 - 837
(2020/12/07)

Primary Sulfonamide Functionalization via Sulfonyl Pyrroles: Seeing the N?Ts Bond in a Different Light
Despite common occurrence in molecules of value, methods for transforming sulfonamides are distinctly lacking. Here we introduce easy-to-access sulfonyl pyrroles as synthetic linchpins for sulfonamide functionalization. The versatility of the sulfonyl pyrrole unit is shown by generating a variety of products through chemical, electrochemical and photochemical pathways. Preliminary results on the direct functionalization of primary sulfonamides are also provided, which may lead to new modes of activation.
Ozaki, Tomoya,Yorimitsu, Hideki,Perry, Gregory J. P.
p. 15387 - 15391
(2021/10/04)

Deoxyfluorination of alcohols with aryl fluorosulfonates
Aryl fluorosulfonates are developed as a deoxyfluorinating reagent in the transformation of primary and secondary alcohols into the corresponding alkyl fluorides. These reagents feature easy availability, low-cost, high stability and high efficiency. Diverse functionalities including aldehyde, ketone, ester, halogen, nitro, alkene, and alkyne are well tolerated under mild reaction conditions.
Fei, Zhongbo,Hu, Jinbo,Li, Wei,Liu, Qinghe,Ni, Chuanfa,Wang, Xiu,Zhou, Min
supporting information
p. 8170 - 8173
(2021/08/23)

Radical Decarboxylative Carbometalation of Benzoic Acids: A Solution to Aromatic Decarboxylative Fluorination
Abundant aromatic carboxylic acids exist in great structural diversity from nature and synthesis. To date, the synthetically valuable decarboxylative functionalization of benzoic acids is realized mainly by transition-metal-catalyzed decarboxylative cross couplings. However, the high activation barrier for thermal decarboxylative carbometalation that often requires 140 °C reaction temperature limits both the substrate scope as well as the scope of suitable reactions that can sustain such conditions. Numerous reactions, for example, decarboxylative fluorination that is well developed for aliphatic carboxylic acids, are out of reach for the aromatic counterparts with current reaction chemistry. Here, we report a conceptually different approach through a low-barrier photoinduced ligand to metal charge transfer (LMCT)-enabled radical decarboxylative carbometalation strategy, which generates a putative high-valent arylcopper(III) complex, from which versatile facile reductive eliminations can occur. We demonstrate the suitability of our new approach to address previously unrealized general decarboxylative fluorination of benzoic acids.
Xu, Peng,López-Rojas, Priscila,Ritter, Tobias
supporting information
p. 5349 - 5354
(2021/05/05)

Preparation method of methyl sulfone compound
The invention discloses a synthesis method of a methyl sulfone compound, which comprises the following steps: by using an iodinated compound as a substrate, adding a sulfite compound into the substrate, and using a 1, 4-dioxane solution as a solvent, heating under the protection of nitrogen under the actions of a silicon reagent, a phase transfer catalyst and a palladium catalyst to obtain a crudeproduct; then purifying the crude product, firstly filtering the crude product, and removing the solvent to obtain residues; carrying out silica gel column chromatography on the residues, leaching with eluent, and collecting effluent; combining the effluent containing the product; and concentrating the combined effluent to remove the solvent, and finally carrying out vacuum drying to obtain the target product. The method has the advantages of simple process flow, easiness in product purification, environmental safety and high yield.
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(2021/02/24)

Sulfonylation from sodium dithionite or thiourea dioxide
The cheap and easily available sodium dithionite and thiourea dioxide have been used as the source of sulfonyl group in the synthesis of sulfones and sulfonamides recently. Compared with other methods for the sulfonylation reactions, the strategies using sodium dithionite or thiourea dioxide provide an alternative and complementary route to diverse sulfonyl compounds. During the reaction process, sulfur dioxide anion radical is the key intermediate, which is usually generated from a single electron transfer under suitable conditions. The advantages using sodium dithionite or thiourea dioxide in the sulfonylation reactions include mild conditions and broad substrate scope with excellent functional group compatibility. Further applications by using sodium dithionite and thiourea dioxide in organic transformations will be anticipated.
He, Fu-Sheng,Yang, Min,Ye, Shengqing,Wu, Jie
p. 461 - 464
(2020/06/03)

Sulfoxide and Sulfone Synthesis via Electrochemical Oxidation of Sulfides
The oxidation of diaryl sulfides and aryl alkyl sulfides to the corresponding sulfoxides and sulfones under electrochemical conditions is reported. Sulfoxides are selectively obtained in good yield under a constant current of 5 mA for 10 h in DMF, while sulfones are formed as the major product under a constant current of 10 or 20 mA for 10 h in MeOH. The oxygen of both the sulfoxide and sulfone function is derived from water.
Lee, Sunwoo,Park, Jin Kyu
p. 13790 - 13799
(2021/10/12)

Synergistic cooperative effect of CF3SO2Na and bis(2-butoxyethyl)ether towards selective oxygenation of sulfides with molecular oxygen under visible-light irradiation
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
supporting information
p. 496 - 500
(2021/01/28)

Flow Electrosynthesis of Sulfoxides, Sulfones, and Sulfoximines without Supporting Electrolytes
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
p. 15961 - 15972
(2021/07/20)

PROTEIN-MACROMOLECULE CONJUGATES AND METHODS OF USE THEREOF
The present disclosure provides protein-macromolecule conjugates, releasable linkers, and macromolecules, as defined herein. The disclosed conjugates provide unique properties that are based at least upon the properties of linker and number of linker-Macromolecule moieties. Also provided herein are a method of synthesis and use of conjugates in treating diseases and disorders.
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(2021/04/10)

Formation and kinetic studies of manganese(IV)-oxo porphyrins: Oxygen atom transfer mechanism of sulfide oxidations
Visible light irradiation of photo-labile porphyrin-manganese(III) chlorates or bromates (2) produced manganese(IV)-oxo porphyrins [MnIV(Por)(O)] (Por = porphyrin) (3) in three porphyrin ligands. The same oxo species 3 were also formed by chemical oxidation of the corresponding manganese(III) precursors (1) with iodobenzene diacetate, i.e. PhI(OAc)2. The systems under study include 5,10,15,20-tetra(pentafluorophenyl)porphyrin?manganese(IV)-oxo (3a), 5,10,15,20-tetra(2,6-difluorophenyl)porphyrin?manganese(IV)-oxo (3b), and 5,10,15,20-tetramesitylporphyrin?manganese(IV)-oxo (3c). As expected, complexes 3 reacted with thioanisoles to produce the corresponding sulfoxides and over-oxidized sulfones. The kinetics of oxygen atom transfer (OAT) reactions of these generated 3 with aryl sulfides were studied in CH3CN solutions. Second-order rate constants for sulfide oxidation reactions are comparable to those of alkene epoxidations and activated C[sbnd]H bond oxidations by the same oxo species 3. For a given substrate, the reactivity order for the manganese(IV)-oxo species was 3a > 3b > 3c, consistent with expectations on the basis of the electron-withdrawing capacity of the porphyrin macrocycles. Free-energy Hammett analyses gave near-linear correlations with σ values, indicating no significant positive charge developed at the sulfur during the oxidation process. The mechanistic results strongly suggest [MnIV(Por)(O)] reacts as a direct OAT agent towards sulfide substrates through a manganese(II) intermediate that was detected in this work. However, an alternative pathway that involves a disproportionation of 3 to form a higher oxidized manganese(V)-oxo species may be significant when less reactive substrates are present. The competition product studies with the Hammett correlation plot confirmed that the observed manganese(IV)-oxo species is not the true oxidant for the sulfide oxidations catalyzed by manganese(III) porphyrins with PhI(OAc)2.
Klaine, Seth,Bratcher, Fox,Winchester, Charles M.,Zhang, Rui
(2020/01/08)

Visible light generation of chromium(V)-oxo salen complexes and mechanistic insights into catalytic sulfide oxidation
Visible light irradiation of the photo-labile salen-chromium(III) chlorate or bromate precursors produced salen-chromium(V)-oxo complexes that were spectroscopically and kinetically indistinguishable from those formed by chemical oxidation of chromium(III) salens with PhI(OAc)2. The photochemistry observed in this work is ascribed to the heterolytic cleavage of the O-X bond in the apical counterion that results in a two-electron oxidation of the metal to form the chromium(V)-oxo species. Second-order rate constants for oxidation reactions of 3 with organic substrates were determined under pseudo-first order condition, and particularly low level of reactivity for sulfide oxidations was observed. In this study, chromium(III) salen complexes effectively catalyzed the oxidation of aryl sulfides into sulfoxides with PhI(OAc)2 in the presence of a small amount of water. The competition product studies with the Hammett correlation plot indicated that the observed chromium(V)-oxo species is not likely to serve as the major oxidant for the sulfide oxidations catalyzed by chromium(III) salens with PhI(OAc)2.
Dames, Angeline,Fung Lee, Ngo,Klaine, Seth,Zhang, Rui
(2020/04/27)

Accurate Regulating of Visible-Light Absorption in Polyoxotitanate-Calix[8]arene Systems by Ligand Modification
With use of a macrocyclic polyphenol, tert-butylcalix[8]arene (TBC[8]), as ligands, a series of TBC[8]-stabilized {Ti4O2}clusters, containing penta- and hexacoordinated Ti centers, were synthesized. Such complexes are "core-shell" shaped containing a {Ti4O2} core arranged in a zigzag fashion. While outer walls of the clusters are decorated by deprotonated TBC[8], their upper and lower surfaces can be modified by various O- or N-donor ligands, and the ratio of the penta- and hexacoordinated Ti(IV) centers in the {Ti4O2} core can be precisely regulated from 4:0, to 3:1, to 2:2, to 1:3, and finally to 0:4. The combined coordination of different ligands in the axial direction shows significant influence on the adsorption of the TBC[8]-Ti4 system in the visible-light region, and their absorption edge can be precisely regulated from 600 to 700 nm. The above structural functionalization in the TBC[8]-Ti4 system also tunes their photocatalytic H2 production activities and oxidative desulfurization ability. Thus, for the first time, by confining the polyoxotitanium cluster in macrocyclic molecules, we provide an example of understanding the structure-property relationship of titanium-oxygen materials by ligand modification.
Liu, Chao,Yang, Xin-Xue,Yi, Xiao-Yi,Yu, Wei-Dong
(2020/06/08)

Electrochemical Synthesis of Sulfinic Esters via Aerobic Oxidative Esterification of Thiophenols with Alcohols
A method for the electrochemical synthesis of sulfinic esters by aerobic oxidative coupling of thiophenols and alcohols has been developed. Using electrons as the redox reagent and O 2in air as the oxygen source, the reactions proceeded smoothly at room temperature, even for a gram-scale preparation. No use of catalyst, clean redox reagent, green and abundant oxygen source, and mild reaction conditions make this strategy eco-friendl.
Zhou, Hongyan,Duan, Jiaokui,Xie, Dongtai,Yang, Jingya,Ma, Ben,Wang, Ganggang,Wu, Chengqi,Wang, Xi-Cun
p. 2705 - 2712
(2020/09/15)

Efficient electrosynthesis of sulfinic esters via oxidative cross-coupling between alcohols and thiophenols
A new protocol for S O bond formation was developed by electrochemical oxidative cross-coupling between alcohols and thiophenols. With this strategy, a series of valuable sulfinic ester derivatives were synthesized up to 96% yield from basic starting materials. A preliminary mechanistic investigation reveals that this reaction involves oxygen reduction reaction (ORR).
Gong, Fengping,Lu, Fangling,Zuo, Lin,Wang, Qi,Li, Ru,Hu, Jiaxin,Li, Zhen,Takfaoui, Abdelilah,Lei, Aiwen
p. 192 - 196
(2019/09/13)

A Three-Component Derivatization Protocol for Determining the Enantiopurity of Sulfinamides by 1H and 19F NMR Spectroscopy
A practically simple three-component chiral derivatization protocol has been developed to determine the enantiopurity of eight S-chiral sulfinamides by 1H and 19F NMR spectroscopic analysis, based on their treatment with a 2-formylphenylboronic acid template and enantiopure pinanediol to afford a mixture of diastereomeric sulfiniminoboronate esters whose diastereomeric ratio is an accurate reflection of the enantiopurity of the parent sulfinamide.
Groleau, Robin R.,Chapman, Robert S. L.,Ley-Smith, Harry,Liu, Liyuan,James, Tony D.,Bull, Steven D.
p. 1208 - 1215
(2020/01/02)

General sulfone construction: Via sulfur dioxide surrogate control
A highly efficient one-step synthesis of alkyl-alkyl and aryl-alkyl sulfones with a facile combination of halides, sulfur dioxide surrogates and phosphate esters is described. When thiourea dioxide was employed as a reductive sulfur dioxide surrogate, alkyl-alkyl sulfones were obtained under transition metal free conditions. Aryl-alkyl sulfones were obtained with an extremely low catalytic loading (0.2 mol%) via altering the mask of sulfur dioxide surrogates to sodium dithionite. A phosphate ester was employed as a stable and readily available alkyl source. Notably, this protocol has been applied to the late-stage modification of natural products and bioactive molecules.
Chen, Shihao,Li, Yaping,Wang, Ming,Jiang, Xuefeng
supporting information
p. 322 - 326
(2020/02/13)

Selective oxidation of (hetero)sulfides with molecular oxygen under clean conditions
The development of eco-friendly and switchable catalytic systems for the conversion of a sole raw-material into distinct high-value products is a particularly attractive concept and a daunting synthetic challenge. In the present work, the first example of efficient and selective oxidation of sulfides to sulfones and sulfoxides using molecular oxygen under clean conditions was established.
Liu, Kai-Jian,Deng, Ji-Hui,Yang, Jie,Gong, Shao-Feng,Lin, Ying-Wu,He, Jun-Yi,Cao, Zhong,He, Wei-Min
supporting information
p. 433 - 438
(2020/02/13)

Oxidation of aromatic sulfides with molecular oxygen: Controllable synthesis of sulfoxides or sulfones
The recent development of selective oxidation of aromatic sulfides with molecular oxygen was highlighted. The sulfoxides and sulfones could be obtained by simply switching the reaction media, i.e., bis(2-butoxyethyl)ether (BBE) or poly(ethylene glycol)dimethyl ether (PEGDME). The application of the high-boiling-point polyether as an initiator and green media can eliminate the need of large quantities of additives and volatile solvents. This strategy represents an economic and eco-friendly method that could find potential applications.
Tang, Lili,Du, Kejie,Yu, Bing,He, Liangnian
p. 2991 - 2992
(2020/03/24)

Switchable Synthesis of Aryl Sulfones and Sulfoxides through Solvent-Promoted Oxidation of Sulfides with O2/Air
A practical and switchable method for the synthesis of aryl sulfones and sulfoxides via sulfide oxidation was developed. The chemoselectivities of products were simply controlled by reaction temperature using O2/air as the terminal oxidant and oxygen source. The broad substrate scope, easy realization of gram-scale production, and the simplification of a sulfide oxidation system render the strategy attractive and valuable.
Cheng, Zhen,Sun, Pengchao,Tang, Ailing,Jin, Weiwei,Liu, Chenjiang
supporting information
p. 8925 - 8929
(2019/11/14)

Discovery of a New Family of Polyoxometalate-Based Hybrids with Improved Catalytic Performances for Selective Sulfoxidation: The Synergy between Classic Heptamolybdate Anions and Complex Cations
A series of functional cation-regulated isopolymolybdate-based organic-inorganic hybrid compounds, Na2H2[Mo4O12(C8H17O5N)2]·10H2O (1), Na2[M(Bis-tris)(H2O)]2[Mo7O24]·10H2O [M = Cu, 2; Ni, 3; Co, 4; Zn, 5; Bis-tris = 2,2-Bis(hydroxymethyl)-2,2′,2″-nitrilotriethanol], and (NH4)2[M(Bis-tris)(H2O)]2[Mo7O24]·6H2O (M = Zn, 6; Cu, 7), were synthesized and characterized toward advanced molecular catalyst design. Compound 1 is a covalently bonded adduct, and its self-assembly process can be probed by electrospray ionization mass spectrometry (ESI-MS). Compounds 2-7 are polyoxometalate (POM)-based hybrids containing classic heptamolybdate anions and complex cations with Bis-tris ligands. All of these compounds showed remarkable catalytic effects for selective sulfide oxidation. To the best of our knowledge, compound 5 presents the best catalytic activity so far among the reported hybrid materials with common easily synthesized small-molecule POM clusters and also exhibits outstanding reliability. The conclusion of the catalytic effect is drawn from the results that Zn-based compounds have better catalytic effects than other transition-metal-containing compounds and the compound constructed by Na+ has higher catalytic activity than that constructed by NH4 +. The mechanism studies show that the improvements of the catalytic performance are caused by the synergy between classic heptamolybdate anions and complex cations. ESI-MS data and UV-vis spectra revealed that the POM anions can form intermediate peroxomolybdenum units during catalytic reaction. Further, the combination of the substrate thioanisole with complex cations was characterized by NMR experiments and UV-vis spectra. Thus, a new synergistic mechanism of anions and cations is proposed in which the activated thioanisole is used as a nucleophile to attack the peroxomolybdenum bonds, and this provides a new strategy in the design of reliable POM-based catalysts.
Zhang, Yin,Yu, Wei-Dong,Li, Bin,Chen, Zheng-Fan,Yan, Jun
supporting information
p. 14876 - 14884
(2019/11/05)

Ni/NHC-catalyzed cross-coupling of methyl sulfinates and amines for direct access to sulfinamides
It was reported to develop a simple and convenient method for the Ni/NHC-catalyzed cross-coupling of methyl sulfinates and amines without an acid/base to afford secondary or tertiary sulfinamides in moderate to good yields. The method can provide the desired products with broad substrate scope, good chemoselectivity and good functional group compatibility. The presented approach may enrich the Ni/NHC catalyst system and promote the applications of methyl sulfinates in the organic sulfur chemistry.
Li, Gang-Jian,Pan, You-Lu,Liu, Yan-Ling,Xu, Hai-Feng,Chen, Jian-Zhong
supporting information

(2019/10/28)

A aryl sulfonic acid ester compound synthesis method (by machine translation)
The invention relates to medicine, in the field of organic chemical and fine chemical industry, and in particular relates to a simple, highly efficient method for preparing aryl sulfonic acid ester compound. The method is to four fluoro boric acid aryl diazonium salt, double-(sulfur dioxide) - 1, 4 - diazabicyclo [2.2.2] octane adduct (DABSO) and alcohol as the raw material, the copper salt catalyst, under the presence of an oxidant, nitrogen protection, 50 - 100 °C heating under the reaction conditions, it took 10 - 15 hours synthetic aryl sulfonate. The reaction through simple after treatment can be a high yield a series of aryl sulfonic acid ester compound. On the benzene ring with various substituted aryl four fluoroborates, ordinary primary alcohol, secondary alcohol can be utilized as a reaction substrate, to obtain the corresponding asia sulfonic acid ester. (by machine translation)
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(2019/06/12)

Metal- And oxidant-free electrochemical synthesis of sulfinic esters from thiols and alcohols
An efficient and eco-friendly electrochemical synthesis of various sulfinic esters from thiols and alcohols via sequential S-H/S bond cleavage and double S-O bond formation under mild reaction conditions has been developed. Stoichiometric oxidants, metal catalysts, activating agents and even added bases were avoided in this method, and the only by-product generated from this reaction was dihydrogen gas which could serve as a green source of energy. Various functional groups are compatible with this green protocol which can be easily conducted on a gram-scale.
Ai, Chongren,Shen, Haiwei,Song, Dingguo,Li, Yujin,Yi, Xiao,Wang, Ze,Ling, Fei,Zhong, Weihui
supporting information
p. 5528 - 5531
(2019/10/22)

Electrochemical oxidations of thioethers: Modulation of oxidation potential using a hydrogen bonding network
A highly efficient chemo-selective electrochemical oxidation of thioethers to sulfoxides and sulfones was developed. The hydrogen bonding network generated from hexafluoro-2-propanol (HFIP) and acetic acid (AcOH) plays an important role in the modulation of oxidation potential. The hydrogen bonding network complexes strongly with the sulfoxide, making it less prone to further oxidation. Therefore, thioethers can be selectively electrochemically oxidized to sulfoxides and over-oxidization could be minimized. Moreover, this modulation of oxidization via hydrogen bonding was supported by density functional theory (DFT) calculations and cyclic voltammetry experiments.
Liu, Shiwen,Chen, Bocheng,Yang, Yi,Yang, Yuhao,Chen, Qianjin,Zeng, Xiaojun,Xu, Bo
(2019/11/28)

Insights from kinetic studies of photo-generated compound II models: Reactivity toward aryl sulfides
Iron(IV)-oxo porphyrins [FeIV(Por)O] (Por = poprhyrin), commonly called compound II models, were produced in three electron-deficient ligands by visible light irradiation of highly photo-labile porphyrin-iron(III) bromates or chlorates. The kinetics of oxygen transfer atom (OAT) reactions with aryl sulfides by these photo-generated [FeIV(Por)O] (3) were studied in CH3CN solutions. The iron(IV)-oxo porphyrins under study include 5,10,15,20-tetra(2,6-dichlorophenyl)porphyrin-iron(IV)-oxo (3a), 5,10,15,20-tetra(2,6-difluorophenyl)porphyrin-iron(IV)-oxo (3b), and 5,10,15,20-tetra(pentafluorophenyl)porphyrin-iron(IV)-oxo (3c). As expected, complexes 3 were competent oxidants and reacted rapidly with thioanisoles to give the corresponding sulfoxides with minor over-oxidation sulfones. Apparent second-order rate constants determined under pseudo-first-order conditions for sulfide oxidation reactions are (9.8 ± 0.1) × 102–(3.7 ± 0.3) × 101 M?1 s?1, which are 3 to 4 orders of magnitude greater in comparison to those of alkene epoxidations and activated C–H bond oxidations by the same oxo species. Conventional Hammett analyses gave non-linear correlations, indicating no significant charge developed at the sulfur during the oxidation process. For a given substrate, the reactivity order for the iron(IV)-oxo species was 3c 3b 3a, which is inverted from expectations on the basis of the electron-withdrawing capacity of the porphyrin macrocycles. The absolute rate constants from kinetic studies provided insights into the transient oxidants in catalytic reactions under turnover conditions where actual reactive intermediates are not observable. Our kinetic and catalytic competition results strongly suggest that 3 may undergo a disproportionation reaction to form a higher oxidized iron(IV)-oxo porphyrin radical cations as the true oxidant.
Lee, Ngo Fung,Patel, Dharmesh,Liu, Haiyan,Zhang, Rui
p. 58 - 65
(2018/03/21)

A sustainable oxidative esterification of thiols with alcohols by a cobalt nanocatalyst supported on doped carbon
Here, we developed a new cobalt nanocatalyst supported on N-SiO2-doped activated carbon (Co/N-SiO2-AC), which exhibits excellent catalytic performance towards the oxidative esterification of (hetero)aryl and alkyl thiols with alcohols. A wide array of sulfinic esters were efficiently afforded in an exclusive chemoselective manner. The developed synthetic method proceeds with the merits of mild reaction conditions, broad substrate scope, operational simplicity, good functional group tolerance, earth-abundant and reusable cobalt catalysts, the utilization of renewable alcohols as the coupling partners and molecular O2 as the sole oxidant, which offers a practical method for sustainable synthesis of sulfinic esters.
Zhou, Changjian,Tan, Zhenda,Jiang, Huanfeng,Zhang, Min
supporting information
p. 1992 - 1997
(2018/05/23)

Facile aerobic photo-oxidative synthesis of sulfinic esters
A mild and efficient one-pot visible light-induced method has been developed for the synthesis of sulfinic esters. Sulfinic esters are important structural elements that are frequently found in pharmaceutical agents and biologically active natural products. The routine procedure in the drug discovery and development process to prepare and fully characterize sulfinic esters make them a drug candidate for biological evaluation.
Singh, Pravin K.,Singh, Praveen P.,Srivastava, Vishal
p. 383 - 387
(2019/03/14)

A novel synthesis of aryl methyl sulfones and β-hydroxysulfones from sodium sulfinates and di-tert-butyl peroxide in H2O medium
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
supporting information
p. 524 - 527
(2018/01/10)

Copper-catalyzed: S -methylation of sulfonyl hydrazides with TBHP for the synthesis of methyl sulfones in water
A copper-catalyzed S-methylation of sulfonyl hydrazides with TBHP was efficiently developed, providing a variety of methyl sulfones with good to excellent yields. The reaction can be carried out in water smoothly without any ligand or additive under mild conditions and this catalyst-in-water can be recycled several times.
Yang, Yu,Bao, Yajie,Guan, Qianqian,Sun, Qi,Zha, Zhenggen,Wang, Zhiyong
p. 112 - 116
(2017/08/15)

Efficient synthesis of aliphatic sulfones by Mg mediated coupling reactions of sulfonyl chlorides and aliphatic halides
Sulfonyl chlorides were reduced to anhydrous sulfinate salts with magnesium under sonication. These sulfinates were alkylated to sulfones with alkyl chlorides in the presence of catalytic sodium iodide under sonication. A variety of aliphatic sulfones was efficiently prepared by this one-pot two-step procedure.
Fu, Ying,Xu, Qin-Shan,Li, Quan-Zhou,Du, Zhengyin,Wang, Ke-Hu,Huang, Danfeng,Hu, Yulai
supporting information
p. 2841 - 2845
(2017/04/03)

Catalyst-free oxidation of sulfides to sulfoxides and diethylamine catalyzed oxidation of sulfides to sulfones using Oxone as an oxidant
Abstract: We describe here our journey from the failure of our attempts in controlled oxidation of sulfides to sulfoxides using an Oxone–KBr combination to our success in the development of a catalyst-free protocol for the oxidation of sulfides to sulfoxides using Oxone as an oxidant. We also describe the failure of our attempts at the oxidation of sulfides to sulfones using an excess of Oxone–KBr as well as Oxone, and our success towards the development of a rapid, scalable and chromatography-free protocol for the oxidation of sulfides to sulfones using diethylamine–Oxone as an unprecedented catalyst–oxidant combination.
Kupwade,Khot,Lad,Desai,Wadgaonkar
p. 6875 - 6888
(2017/10/06)

1,1,2,2-Tetrahydroperoxy-1,2-diphenylethane as new oxidant for chemoselective and catalyst free oxidation of sulfides to sulfoxides and sulfones
A catalyst free and chemoselective oxidation of sulfides to sulfoxides or sulfones was developed using 1,1,2,2-tetrahydroperoxy-1,2-diphenylethane as a new oxidant. This scope has shown the achievement of various sulfoxides and sulfones which were obtained selectively in high yields at room temperature.
Khosravi, Kaveh,Naserifar, Shirin,Mahmoudi, Boshra,Khalaji, Kobra
p. 316 - 321
(2017/02/18)

Enantioselective copper catalysed intramolecular C-H insertion reactions of α-diazo-β-keto sulfones, α-diazo-β-keto phosphine oxides and 2-diazo-1,3-diketones; the influence of the carbene substituent
Enantioselectivities in C-H insertion reactions, employing the copper-bis(oxazoline)-NaBARF catalyst system, leading to cyclopentanones are highest with sulfonyl substituents on the carbene carbon, and furthermore, the impact is enhanced by increased steric demand on the sulfonyl substituent (up to 91%ee). Enantioselective intramolecular C-H insertion reactions of α-diazo-β-keto phosphine oxides and 2-diazo-1,3-diketones are reported for the first time.
Shiely, Amy E.,Slattery, Catherine N.,Ford, Alan,Eccles, Kevin S.,Lawrence, Simon E.,Maguire, Anita R.
supporting information
p. 2609 - 2628
(2017/04/01)

Copper-Catalyzed Aerobic Oxidative Reaction of Sulfonyl Hydrazides with Alcohols: An Easy Access to Sulfinates
A Cu-catalyzed aerobic oxidative reaction between sulfonyl hydrazides and alcohols has been developed. In this reaction, sulfonyl hydrazides act as the sulfinic acid precursors to react with alcohols, resulting in sulfinic esters with up to 72 % yield. This catalytic system tolerates a wide range of sulfonyl hydrazide substrates, and represents a new strategy for the transformation of readily available sulfonyl hydrazides.
Du, Bingnan,Li, Zan,Qian, Ping,Han, Jianlin,Pan, Yi
p. 478 - 481
(2016/03/08)

Electrophilic and nucleophilic pathways in ligand oxide mediated reactions of phenylsulfinylacetic acids with oxo(salen)chromium(V) complexes
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
p. 164 - 173
(2016/06/06)

Copper-Mediated Oxidative Fluorination of Aryl Stannanes with Fluoride
A regiospecific method for the oxidative fluorination of aryl stannanes using tetrabutylammonium triphenyldifluorosilicate (TBAT) and copper(II) triflate is described. This reaction is robust, uses readily available reagents, and proceeds via a stepwise protocol under mild conditions (60 °C, 3.2 h). Broad functional group tolerance, including arenes containing protic and nucleophilic groups, is demonstrated.
Gamache, Raymond F.,Waldmann, Christopher,Murphy, Jennifer M.
supporting information
p. 4522 - 4525
(2016/09/28)

A chemoselective oxidation of sulfides to sulfoxides and sulfones using urea-2,2-dihydroperoxypropane as a novel oxidant
Background: Sulfoxides and sulfones have been in the center of attention due to their wide range of promises in various approaches. The functional groups presented in these compounds serve as important building blocks in numerous natural, pharmeceutical and agricultural compounds. These deriatives have been prepared through a multitude of routes which were accompanied by several drawbacks. Therefore, there has been an ever-increasing interest to find a new methodology that leads to the production of these compounds via an environmentally benign path bringing about high yields. Recently, gem-dihydroperoxides have attracted much attention due to their oxidizing power and they have been utilized in several oxidation processes. Methods: We carried out a chemoselective oxidation of sulfides to sulfoxides and sulfones on treatment with urea-2,2-dihydroperoxypropane, a solid oxidant composed of equal amounts of 2,2-dihydroperoxypropane and urea, using THF as the solvent under catalyst-free conditions at room temprature. Results: Sulfides possessing a variety of substitutions namely dialkyl, diaryl, ally l and alkyl-aryl were subjected to the optimized reaction conditions and they could successfully afford different amounts of sulfoxides and sulfones depending on the amount of the oxidant utilized. Based on the results, electron-donating groups accelerated the reaction while electron-withdrawing substituents lowered the reactivity. Conclusion: Urea-2,2-dihydroperoxypropane as a solid oxidant which can be stored for several months without any loss in its activity has proved its capability to oxidize sulfides to sulfoxides and sulfones under catalyst-free and mild conditions. This approach is a cost-effective and environmentally benign methodology via which the products have been synthesized in high yields and short reaction times.
Khosravi, Kaveh,Naserifar, Shirin,Asgari, Atefeh
p. 749 - 756
(2017/02/05)

Synthesis and oxidation catalysis of a Ti-substituted phosphotungstate, and identification of the active oxygen species
In this paper, we report the synthesis of a Ti-substituted phosphotungstate, TBA6[(γ-PW10O36)2Ti4(μ-O)2(μ-OH)4] (I, TBA = tetra-n-butylammonium), and its application to H2O2-based oxidation. Firstly, an organic solvent-soluble dilacunary phosphotungstate precursor, TBA3[γ-PW10O34(H2O)2] (PW10), has been synthesized. By the reaction of PW10 and TiO(acac)2 (acac = acetylacetonate) in an organic medium (acetonitrile), I can be obtained. Compound I possesses a tetranuclear Ti core which can effectively activate H2O2 and shows high catalytic performance for several oxidation reactions, such as epoxidation of alkenes, oxygenation of sulfides, oxidative bromination of unsaturated compounds, and hydroxylation of anisole, giving the corresponding oxidation products with high efficiencies and selectivities. The catalytic performance of I is much superior to those of previously reported Ti-substituted polyoxometalates. In addition, I is highly durable during catalysis and can be reused several times while keeping its high catalytic performance. Furthermore, we have successfully isolated the truly catalytically active species for the present I-catalyzed oxidation, TBA6[(γ-PW10O36)2Ti4(μ-η2:η2-O2)4] (II), and its anion structure has been determined by X-ray crystallographic analysis. All of the four Ti2-μ-η2:η2-peroxo species in II are active for stoichiometric oxidation (without H2O2), and II is included in the catalytic cycle for I-catalyzed oxidation.
Takahashi, Eri,Kamata, Keigo,Kikukawa, Yuji,Sato, Sota,Suzuki, Kosuke,Yamaguchi, Kazuya,Mizuno, Noritaka
p. 4778 - 4789
(2015/10/05)

COMPOSITION, SYNTHESIS, AND USE OF NEW ARYLSULFONYL ISONITRILES
This invention relates to novel isonitriles, including arylsulfonyl isonitriles, and methods for their synthesis. The isonitriles include a conjugated ring system. The structure is designed with the flexibility to have multiple substitution patterns. The isonitriles may be used in applications including, but not limited to, pharmaceutical compositions.
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Paragraph 0143

(2015/09/23)

Alkyl sulfinates: Formal nucleophiles for synthesizing TosMIC analogs
Alkyl sulfinates function as formal nucleophiles in Mannich-type reactions to give sulfonyl formamides, which are readily dehydrated to the corresponding sulfonylmethyl isonitriles. The efficient, two-step synthesis provides a general route to sulfonylmethyl isonitriles from readily available methyl sulfinates or thiols. Mechanistic analysis reveals that the unusual nucleophlicity of the alkyl sulfinates arises from the in situ release of sulfinic acids.
Lujan-Montelongo, J. Armando,Estevez, Angel Ojeda,Fleming, Fraser F.
supporting information
p. 1602 - 1605
(2015/03/04)

PhenoFluorMix: Practical chemoselective deoxyfluorination of phenols
A practical deoxyfluorination with novel deoxyfluorinating reagent PhenoFluorMix, a mixture of N,N'-1,3-bis(2,6-diisopropylphenyl)chloroimidazolium chloride and CsF, is presented. PhenoFluorMix overcomes the challenges associated with hydrolysis of PhenoFluor. PhenoFluorMix does not hydrolyze, is readily available on decagram scale, and is storable in air. In this paper, we demonstrate the practicality of the reagent and exhibit the deoxyfluorination of a variety of phenols and heterocycles.
Fujimoto, Teppei,Ritter, Tobias
supporting information
p. 544 - 547
(2015/03/05)

Dynamics of cetyltrimethylammonium bromide-mediated reaction of phenylsulfinylacetic acid with Cr(VI): Treatment of pseudo-phase models
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
p. 1019 - 1034
(2015/11/27)

In situ-generated chiral iron complex as efficient catalyst for enantioselective sulfoxidation using aqueous H2O2 as oxidant
A series of amino alcohol-derived, Schiff-base ligands L1-L4 were synthesised and characterized. Iron complexes of these ligands [FeL1(acac)], [FeL2(acac)], [FeL3(acac)] and [FeL4(acac)] were generated in situ to catalyze the asymmetric oxidation of prochiral sulfides using aqueous H2O2 as a terminal oxidant. One of these complexes [FeL1(acac)] was identified as a very efficient catalyst for the enantioselective oxidation of a series of alkyl aryl sulfides with excellent enantioselectivity (75-96% ee), conversion (up to 92%) and chemo selectivity (up to 98%). During the optimization process, a series of electron-donating benzoic acid derivatives were found to favour both conversion and enantioselectivity.
Bera, Prasanta Kumar,Kumari, Prathibha,Abdi, Sayed H. R.,Khan, Noor-Ul H.,Kureshy, Rukhsana I.,Subramanian,Bajaj, Hari C.
p. 61550 - 61556
(2015/02/19)

Spectral and mechanistic investigation of Oxidative Decarboxylation of Phenylsulfinylacetic Acid by Cr(VI)
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
p. 17 - 24
(2014/03/21)

Cu-catalyzed fluorination of diaryliodonium salts with KF
A mild Cu-catalyzed nucleophilic fluorination of unsymmetrical diaryliodonium salts with KF is described. This protocol preferentially fluorinates the smaller aromatic ligand on iodine(III). The reaction exhibits a broad substrate scope and proceeds with high chemoselectivity and functional group tolerance. DFT calculations implicate a CuI/CuIII catalytic cycle.
Ichiishi, Naoko,Canty, Allan J.,Yates, Brian F.,Sanford, Melanie S.
supporting information
p. 5134 - 5137
(2013/10/22)

Sulfoxidation on a SiO2-supported Ru complex using O 2/aldehyde system
A site-isolated SiO2-supported Ru-monomer complex, whose structure was characterized by means of solid-state NMR, XPS, UV/vis, and Ru K-edge EXAFS, was found to be efficient for sulfoxidation using an O 2/aldehyde system. Significant enhancement of sulfoxidation rates was observed on the SiO2-supported Ru complex for various sulfide derivatives.
Maity, Niladri,Wattanakit, Chularat,Muratsugu, Satoshi,Ishiguro, Nozomu,Yang, Yong,Ohkoshi, Shin-Ichi,Tada, Mizuki
supporting information; experimental part
p. 4558 - 4565
(2012/07/02)