- Synthesis of cyanate esters based on mono-O-methylated bisphenols with sulfur-containing bridges
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We described a synthetic approach to bisphenol-based monocyanate esters based on mono-O-methylation of parental bisphenols followed by cyanation of the residual phenolic hydroxyl. Structures of the synthesized compounds were determined by the application of IR, NMR 1H and 13C spectroscopies, EI and MALDI mass spectrometry, and purity of the final product was controlled by HPLC. We showed that stability of the cyanate esters depends on the nature of the bridging group. Temperature range of thermally initiated cyclotrimerization of synthesized monocyanate ester, as well as reaction enthalpy, was determined by differential scanning calorimetry (DSC).
- Galukhin, Andrey,Nosov, Roman
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- Redox-Neutral Organometallic Elementary Steps at Bismuth: Catalytic Synthesis of Aryl Sulfonyl Fluorides
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A Bi-catalyzed synthesis of sulfonyl fluorides from the corresponding (hetero)aryl boronic acids is presented. We demonstrate that the organobismuth(III) catalysts bearing a bis-aryl sulfone ligand backbone revolve through different canonical organometallic steps within the catalytic cycle without modifying the oxidation state. All steps have been validated, including the catalytic insertion of SO2 into Bi-C bonds, leading to a structurally unique O-bound bismuth sulfinate complex. The catalytic protocol affords excellent yields for a wide range of aryl and heteroaryl boronic acids, displaying a wide functional group tolerance.
- Cornella, Josep,Magre, Marc
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p. 21497 - 21502
(2022/01/03)
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- Heterogeneous copper-catalyzed synthesis of diaryl sulfones
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A carbon-supported copper nanoparticle (Cu-NP) with high catalytic activity for the synthesis of diaryl sulfones is reported. For the first time, this Cu-NP is proved to be able to effectively promote the reaction of arylboronic acids and arylsulfonyl hydrazides to generate diaryl sulfones at room temperature. The reaction shows excellent substrate universality, and substrates with different substituents can undergo the reaction smoothly, leading to the desired products in good yields. The Cu-NP is found to be made of low valence Cu based on XRD. Hence, the reaction catalyzed by the Cu-NP is believed to involve a Cu-mediated organometallic cycle.
- Gong, Xinchi,Qu, Lingling,Shen, Zhengqi,Wang, Ganghu,Zhu, Chunyin
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supporting information
p. 10662 - 10668
(2021/12/27)
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- Visible-light-driven electron donor-acceptor complex induced sulfonylation of diazonium salts with sulfinates
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This work reports an efficient sulfonylation reaction enabled by a visible-light-induced radical coupling reaction between phenyl/heterocyclic diazonium salts and sulfinates. Mechanistic experiments disclosed the formation of a versatile electron donor-acceptor (EDA) complex. This transformation is characterized by an easy operational procedure under mild conditions which avoids transition metals, ligands, catalysts, and oxidants.
- Cheng, Lan,Guo, Jianbo,Li, Yufei,Liang, Xin,Wang, Qingmin,Xia, Qing,Zhang, Pei,Zhang, Weihua
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supporting information
p. 8865 - 8870
(2021/11/30)
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- Sulfonylation of Bismuth Reagents with Sulfinates or SO2through BiIII/BiV Intermediates
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Studies to explore the catalytic activities of main-group elements are attractive. We report here our study of sulfonylation of bismuth reagents with sulfinates or SO2 surrogates. Under oxidative conditions, triarylbismuthines and sulfinates were transformed into diaryl sulfones. A transition-metal-like two-electron redox process at the Bi center was achieved in this reaction. Sulfur dioxide generated in situ can also replace sulfinates to deliver the corresponding symmetric diaryl sulfones. A rational mechanism for this reaction was also proposed that involves a Bi(III)-Bi(V) manifold.
- Zhao, Fengqian,Wu, Xiao-Feng
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supporting information
p. 2400 - 2404
(2021/07/28)
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- Pd/NHC-catalyzed arylsulfonylation of boronic acids: A general and direct protocol to access diarylsulfones
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For the first time, robust NHC-Pd complexes have been demonstrated as highly efficient catalysts in the direct arylsulfonylation of boronic acids. Remarkably, a broad number of diaryliodonium salts as powerful electrophilic arylation reagents are well compatible to form functional ortho-substituted diarylsulfones in satisfactory yields. Owing to the stronger σ-donor and weaker π-acceptor properties, the acenaphthoimidazolylidene ligands exhibit higher catalytic activities towards this challenging one-step arylsulfonylation reaction.
- Zhu, Haibo,Yang, Liu,Meng, Jia,Xie, Zongbo,Le, Zhang-Gao,Tu, Tao
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supporting information
(2020/12/29)
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- Electrochemical oxygenation of sulfides with molecular oxygen or water: Switchable preparation of sulfoxides and sulfones
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A practical and eco-friendly method for the controllable aerobic oxygenation of sulfides by electrochemical catalysis was developed. The switchable preparation of sulfoxides and sulfones was effectively controlled by reaction time, in which both molecular oxygen and water can be used as the oxygen source under catalyst and external oxidant-free conditions. The electrochemical protocol features a broad substrate scope and excellent site selectivity and is successfully applied to the modification of some sulfide-containing pharmaceuticals and their derivatives. This journal is
- Li, Jin-Heng,Li, Yang,Sun, Qing,Xue, Qi,Zhang, Ting-Ting
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supporting information
p. 10314 - 10318
(2021/12/17)
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- Synthetic method of diarylsulfone compound
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The invention relates to a synthetic method of a diarylsulfone compound. The method is characterized in that a copper complex and aryl sulfonyl hydrazide are dissolved in an organic solvent, air serves as an oxidizing agent, a reaction is conducted at the room temperature, separation and purification are conducted to obtain the corresponding diarylsulfone compound, the molar ratio of the copper complex to the aryl sulfonyl hydrazide is (0.01-0.03):1.0, and the reaction time is 2-5 h. Compared with the prior art, the synthesis process provided by the invention has excellent selectivity and highyield, the catalyst copper complex in the reaction can catalyze the self-coupling of aryl sulfonyl hydrazide to synthesize the diarylsulfone compound at room temperature, and the reaction has the characteristics of mild and simple conditions, wide substrate range, convenient product separation, high reaction efficiency and the like.
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Paragraph 0029; 0033-0036
(2020/10/04)
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- Facile synthesis of diarylsulfones from arenes and 3CdSO4·xH2O via mechanochemistry
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A variety of substituted diarylsulfones could be synthesized by simple arenes and 3CdSO4·xH2O in the presence of P2O5 under high-speed ball milling. It was suggest the aromatic sulfonation was performed by arene and in situ generated H2SO4, following-up by electrophilic substitution with another arene to give diarylsulfone.
- Qin, Shuai,Zhang, Pu,Qin, Yu-Jun,Guo, Zhi-Xin
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supporting information
(2020/01/06)
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- Synthesis and nano-Pd catalyzed chemoselective oxidation of symmetrical and unsymmetrical sulfides
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A highly chemoselective, efficient and nano-Pd catalyzed protocol for the rapid construction of sulfoxides and sulfones via the oxidation of symmetrical and unsymmetrical sulfides using H2O2 as an oxidant has been developed, respectively. The ready availability of starting materials, easy recovery and reutilization of the catalyst, wide substrate scope, and high yields make this protocol an attractive alternative. The process also involves the metal-free and microwave-promoted synthesis of symmetrical diarylsulfides, and FeCl3-mediated preparation of symmetrical diaryldisulfides through the reaction of arenediazonium tetrafluoroborates with Na2S·9H2O as a sulfur source. In addition, unsymmetrical sulfides were generated via the K2CO3-mediated reaction of arenediazonium tetrafluoroborates with symmetrical disulfides.
- Li, Xing,Du, Jia,Zhang, Yongli,Chang, Honghong,Gao, Wenchao,Wei, Wenlong
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p. 3048 - 3055
(2019/03/21)
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- Palladium-catalyzed one-step synthesis of symmetrical diaryl sulfones from aryl halides and a sulfur dioxide surrogate
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A convenient method for the one-step synthesis of symmetrical diaryl sulfones from aryl halides has been developed. A keystone of the method is the use of K2S2O5, which can be easily and safely handled, as a sulfur dioxide surrogate. The palladium catalyst bearing P(t-Bu)3 as a ligand enables formation of the desired sulfones without significant formation of byproducts.
- Tanaka, Hiromichi,Konishi, Hideyuki,Manabe, Kei
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supporting information
p. 760 - 763
(2019/08/02)
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- Organic photoredox catalysis enabled cross-coupling of arenediazonium and sulfinate salts: Synthesis of (un)symmetrical diaryl/alkyl aryl sulfones
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We disclose herein the first transition-metal-and external oxidant/reductant-free visible-light-mediated synthesis of (un)symmetrical diaryl/alkyl aryl sulfones from arenediazonium tetrafluoroborates and sodium sulfinates using eosin Y as an organic photoredox catalyst. The utilization of visible light as an inexpensive and ecosustainable energy source, operational simplicity, ambient temperature and clean reaction in aqueous acetonitrile are the salient features of the developed protocol. The desired sulfones were also synthesized via a one-pot, two-step process directly from anilines and sulfinate salts in good to excellent yields.
- Chawla, Ruchi,Yadav, Lal Dhar S.
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supporting information
p. 4761 - 4766
(2019/05/24)
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- Selective Synthesis of ortho-Substituted Diarylsulfones by Using NHC-Au Catalysts under Mild Conditions
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A single-step gold(I)-catalyzed chemoselective protocol to access ortho-substituted diarylsulfones has been established. Acenaphthoimidazolylidene gold complexes are effective catalysts for the arylsulfonylation of boronic acids by potassium metabisulfite (K2S2O5) and diaryliodonium salts to access (poly-)ortho-substituted diarylsulfones even in gram scale. Unlike the transition metal-catalyzed two-component coupling systems, the sterically hindered aryl groups in diaryliodonium salts are preferentially transferred over less bulky ones to form synthetically difficult targets, including those of pharmaceutical importance.
- Zhu, Haibo,Shen, Yajing,Wen, Daheng,Le, Zhang-Gao,Tu, Tao
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supporting information
p. 974 - 979
(2019/02/14)
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- A practical synthesis of aryl sulfones via cross-coupling of sulfonyl hydrazides with aryltriazenes using copper/ionic liquid combination
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A new and efficient approach adopting copper-catalyzed cross-coupling of sulfonyl hydrazides with aryltriazenes has been developed to synthesize aryl sulfones using Br?nsted acidic ionic liquid as promoter under ambient conditions. The process employs stable and easy to handle reacting partners, and is endowed with broad substrate scope.
- Pandey, Anand Kumar,Kumar, Saurabh,Singh, Rahul,Singh, Krishna Nand
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supporting information
p. 6704 - 6709
(2018/10/15)
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- From Anilines to Aryl Ethers: A Facile, Efficient, and Versatile Synthetic Method Employing Mild Conditions
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We have developed a simple and direct method for the synthesis of aryl ethers by reacting alcohols/phenols (ROH) with aryl ammonium salts (ArNMe3+), which are readily prepared from anilines (ArNR′2, R′=H or Me). This reaction proceeds smoothly and rapidly (within a few hours) at room temperature in the presence of a commercially available base, such as KOtBu or KHMDS, and has a broad substrate scope with respect to both ROH and ArNR′2. It is scalable and compatible with a wide range of functional groups.
- Wang, Dong-Yu,Yang, Ze-Kun,Wang, Chao,Zhang, Ao,Uchiyama, Masanobu
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supporting information
p. 3641 - 3645
(2018/03/13)
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- Visible-Light Photoredox/Nickel Dual Catalysis for the Cross-Coupling of Sulfinic Acid Salts with Aryl Iodides
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An efficient cross-coupling of sodium or lithium sulfinates with aryl iodides, using a combination of nickel and photoredox catalysis, is described. The dual catalyst system enables a versatile synthesis of aryl sulfones at room temperature in good yields and displays a broad functional group compatibility. The potential utility of this method in the late-stage diversification of complex molecules and in the conversion of organolithium reagents and sulfur dioxide into sulfones is demonstrated.
- Liu, Nai-Wei,Hofman, Kamil,Herbert, André,Manolikakes, Georg
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supporting information
p. 760 - 763
(2018/02/09)
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- The synthesis of diarylsulfones with simple arenes and K2S2O8 through double C-S bond formation
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An unprecedented double C-S bond formation method has been developed to prepare both symmetric and unsymmetric diarylsulfones with simple arenes in a single step. This represents the first example that K2S2O8 can be employed as a highly effective sulfonating agent to synthesize diarylsulfones. The reaction demonstrates excellent reactivity, good functional group tolerance and high yields.
- Yang, Yiqing,Chen, Zhang,Rao, Yu
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supporting information
p. 15037 - 15040
(2014/12/11)
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- Synthesis of symmetrical diaryl sulfone by homocoupling of sodium arylsulfinate
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An efficient practical homocoupling reaction of sodium arylsulfinate promoted by Cu(II) is reported whereby symmetrical diaryl sulfone derivatives are obtained with high selectivity and reactivity by intermolecular cross-coupling. This homocoupling reacti
- Peng, Yao
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p. 265 - 268
(2014/06/09)
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- DABSO-based, three-component, one-pot sulfone synthesis
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The addition of Grignard reagents or organolithium reagents to the SO 2-surrogate DABSO generates a diverse set of metal sulfinates, suitable for direct conversion to sulfone products. The metal sulfinates can be trapped in situ with a wide range of C-electrophiles, including alkyl, allyl, and benzyl halides, epoxides, and (hetero)aryliodoniums.
- Deeming, Alex S.,Russell, Claire J.,Hennessy, Alan J.,Willis, Michael C.
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supporting information
p. 150 - 153
(2014/01/23)
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- Selective synthesis of sulfoxides and sulfones from sulfides using silica bromide as the heterogeneous promoter and hydrogen peroxide as the terminal oxidant
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Silica bromide as a heterogeneous promoter and reagent is prepared from the reaction of silica gel with PBr3as a non-hydroscopic, filterable, cheap, and stable yellowish powder that can be stored for months. The results show that silica bromide is a suitable and efficient promoter for the chemoselective oxidation of sulfides to the corresponding sulfoxides or sulfones in the presence of 30% H2O2in acetonitrile. The excellent yields, heterogeneous conditions, simplicity, compatibility with a variety of functionalities, and ease of isolation of the products make our procedure a practical alternative.
- Maleki, Behrooz,Hemmati, Saba,Sedrpoushan, Alireza,Ashrafi, Samaneh Sedigh,Veisi, Hojat
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p. 40505 - 40510
(2015/02/03)
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- Catalytic Friedel-Crafts acylation: Magnetic nanopowder CuFe 2O4 as an efficient and magnetically separable catalyst
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Catalytic regioselective Friedel-Crafts acylation of an array of anisoles/arenes with various acid chlorides using 5-20 mol % of magnetic nanopowder CuFe2O4 is reported. Unlike the conventional Friedel-Crafts reactions, which are catalyzed by moisture sensitive homogeneous catalysts/promoters, the nanopowder CuFe2O4 catalyst is moisture insensitive and the product/ketone-catalyst isolation is easily achieved using the magnetic properties of CuFe2O4.
- Parella, Ramarao,Naveen,Kumar, Amit,Babu, Srinivasarao Arulananda
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p. 1738 - 1742
(2013/03/28)
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- Scope and regioselectivity of iridium-catalyzed C-H borylation of aromatic main-chain polymers
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An efficient functionalization of aromatic main-chain polymers was established using a combination of iridium-catalyzed borylation of aromatic C-H bonds and the Suzuki-Miyaura coupling reaction. Comparative studies of various iridium catalysts and borylation reagents show that [Ir(OMe)(COD)]2 is significantly more active than [IrCl(COD)]2, and bis(pinacolato)diboron induces higher efficiency than pinacolborane. The regioselectivity of the borylation was investigated using model compounds that mimic the repeating unit structure of poly(arylene ether sulfone). The C-H bonds of the sulfone model compound were more reactive than those of the bisphenol model compound, and the borylation occurred preferentially at the meta position to the sulfone moiety owing to steric hindrance and electronic effects. The glass transition temperature of the borylated polymer increases with increasing concentration of pinacolboronic ester group. The pinacolboronic ester group could be conveniently converted to boronic acid [B(OH)2] and potassium trifluoroborate (BF3K), which could also serve as versatile reactive sites for the synthesis of a wide range of functionalized polymers via Suzuki-Miyaura couplings.
- Chang, Ying,Lee, Hanniel H.,Kim, Se Hye,Jo, Tae Soo,Bae, Chulsung
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p. 1754 - 1764
(2013/04/24)
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- Palladium-catalyzed aromatic sulfonylation: A new catalytic domino process exploiting in situ generated sulfinate anions
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Allylic sulfones are excellent precursors of aryl sulfones via a new Pd-catalyzed domino sequence involving in situ generation of sulfinate anions and subsequent cross-coupling with aryl -iodides or bromides. Georg Thieme Verlag Stuttgart · New York.
- Le Duc, Ga?tan,Bernoud, Elise,Prestat, Guillaume,Cacchi, Sandro,Fabrizi, Giancarlo,Iazzetti, Antonia,Madec, David,Poli, Giovanni
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supporting information; experimental part
p. 2943 - 2946
(2012/01/05)
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- Synthesis of symmetric diaryl sulfones with dimethyl sulfate
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In this procedure dimethyl sulfate was used for preparation of symmetric diaryl sulfones. First, dimethyl sulfate was treated with pyridine, then activated by Tf2O to generate SO2 as the functional group for synthesis of diaryl sulfones. It is noticeable that this reaction was carried out in moderate conditions and products obtained in short times and good yields.
- Khodaei, Mohammad Mehdi,Nazari, Ehsan
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experimental part
p. 390 - 391
(2010/07/06)
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- TAPC-promoted oxidation of sulfides and deoxygenation of sulfoxides
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Figure presented. 1,3,5-Triazo-2,4,6-triphosphorine-2,2,4,4,6,6- tetrachloride (TAPC) was found to be an efficient promoter for the oxidation of sulfides and deoxygenation of sulfoxides. Excellent yields, short reaction time, easy and quick isolation of the products, solvent-free process, and excellent chemoselectivity are the main advantages of this procedure.
- Bahrami, Kiumars,Khodaei, Mohammad M.,Sheikh Arabi, Mehdi
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supporting information; experimental part
p. 6208 - 6213
(2010/11/04)
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- Tantalum carbide or niobium carbide catalyzed oxidation of sulfides with hydrogen peroxide: Highly efficient and chemoselective syntheses of sulfoxides and sulfones
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The oxidation of sulfides with 30% hydrogen peroxide catalyzed by tantalum carbide provided the corresponding sulfoxides in high yields. The reaction of sulfides with 30% hydrogen peroxide catalyzed by niobium carbide efficiently afforded the corresponding sulfones. These catalysts can easily be recovered from the reaction mixture and may be repeatedly used as catalysts for the oxidation without losing their activity. Georg Thieme Verlag Stuttgart New York.
- Kirihara, Masayuki,Itou, Atsushi,Noguchi, Takuya,Yamamoto, Junya
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experimental part
p. 1557 - 1561
(2010/09/05)
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- Oxidation kinetics of some sulfoxides with N,N-dibromobenzene sulfonamide
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The kinetics of oxidation of some sulfoxides with dibromamine-B yielding sulfones was investigated in presence of HgII, and the rate equation, kobs = k3K2K′h[S]/[RNH 2] + K′h was found to be valid. The reaction involves two distinct pathways namely initial fast step and a subsequent slow step. The chloride ions have no effect on the reactivity of sulfoxides. Sulfoxides containing electron-attracting substituents retard the reactivity while those containing electron-releasing constituents accelerate the rate of oxidation. Exner plot confirms the operation of same mechanism in all the sulfoxides studied. Electrophilic addition of Br+ to sulfur atom results in an electron-deficient sulfonium centre which decomposes in a slow rate-limiting step. The rate coefficients are treated in terms of multiparametric extensions of the Hammett equation to have more insight into the mechanistic aspects.
- Meenakshisundaram, Subbiah,Amutha
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p. 679 - 682
(2008/09/18)
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- Rapid and highly chemoselective biomimetic oxidation of organosulfur compounds with tetrabutylammonium peroxymonosulfate in the presence of manganese meso-tetraphenylporphyrin and imidazole
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A novel and efficient method is described for the immediate oxidation of different organosulfur compounds using tetrabutylammonium peroxymonosulfate in the presence of manganese meso-tetraphenylporphyrin and imidazole. The method is highly chemoselective and the yields are excellent.
- Iranpoor, Nasser,Mohajer, Daryoush,Rezaeifard, Abdol-Reza
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p. 3811 - 3815
(2007/10/03)
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- Synthesis of deuterated 4, 4′-diaminodiphenylsulfone (Dapsone) and related analogs
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A general scheme tor the synthesis ot 4,4′-diaminodiphenylsulfone-d5 (Dapsone) from aniline-d5 is described. The method may have general application and the preparation of the related analogs, 4,4′-dimethylaminodiphenyl sulfone from aniline-d5 and 4,4′-dimethoxydiphenyl sulfone from phenol-d5, is also described. Copyright
- Gannett, Peter M.,Johnson II, Edward M.,Grimes, Michael A.,Myers, Alan L.,Deavers III, Robert E.,Tracy, Timothy S.
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p. 107 - 114
(2007/10/03)
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- Selected sulfonyl compounds as anticancer/antimalarial agents
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The synthesis and biological testing of a series of sulfonyl phenols and sulfonyl aryl methyl ethers has revealed that p-methoxyphenyl p-toluenesulfonate is a very selective and effective antimalarial agent which shows pronounced activity against human skin cancer cells. Application of a counter-attack strategy permits the direct preparation of the requisite tosylate ether from the bis(tosylate) of dihydroquinone.
- Langler, Richard F.,Paddock, Robert L.,Thompson, David B.,Crandall, Ian,Ciach, Michelle,Kain, Kevin C.
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p. 1127 - 1133
(2007/10/03)
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- An efficient method for aromatic Friedel-Crafts alkylation, acylation, benzoylation, and sulfonylation reactions
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Aromatic electrophilic substitution reactions such as alkylation, acylation, benzoylation, and sulfonylation were studied in the presence of a catalytic amount of Cu(OTf)2 and Sn(OTf)2. Cu(OTf)2 was very efficient for alkylation, acylation, and benzoylation reactions. However, in case of sulfonylation reactions, Sn(OTf)2 gave better results.
- Singh, Ravi P,Kamble, Rajesh M,Chandra, Kusum L,Saravanan,Singh, Vinod K
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p. 241 - 247
(2007/10/03)
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- Acylation and related reactions under microwaves. 4. Sulfonylation reactions of aromatics
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Solvent-free sulfonylation of benzene and its activated or deactivated derivatives were carried out under microwave (MW) irradiation and a catalytic amount of iron(III) chloride, which, under these conditions, is more, active than other metallic salts. With more reactive and/or nonvolatile reagents (anisole, xylenes, mesitylene) expeditious conditions (short reaction time at constant MW power without control of the temperature) were used. With less reactive and/or low-boiling reagents (benzene, toluene, halobenzenes), the rise in temperature and the increase of reaction time were controlled either by sequential MW irradiation or by a temperature order. It was shown that MWs cause preferential interactions with polar species present in the reaction, especially the aryl sulfone and its FeCl3-complexed form. A MW nonthermal effect was not observed when identical temperature gradients were produced by classical heating and MW irradiation, and if reaction temperature was strictly controlled.
- Marquie,Laporterie,Dubac,Roques,Desmurs
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p. 421 - 425
(2007/10/03)
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- Catalysis of the oxone oxidation of some sulphoxides by Ru(III)
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The kinetics of oxidation of some sulphoxides with oxone in the presence of Ru(III) has been described. The catalytic activity of Ru(III) has been demonstrated with several diaryl, dialkyl and alkyl aryl sulphoxides, all of which are found to undergo oxidation under homogenous conditions. Homolytic fission of the peroxide bond is ruled out. The reaction exhibits first-order dependence on the concentration of Ru(III) is observed. Reactions have small substituent effects with ρ = -0.3. The rates increase substantially with increasing water content in aqueous acetic acid. The rate data are consistent with the mechanism involving electron transfer from electrophilic perhydroxyl oxygen of oxone to sulphoxide. The rate coefficients are treated in terms of multiparameter extensions of the Hammett equation to have more insight into the mechanistic aspects.
- Meenakshisundaram, Subbiah,Sathiyendiran, V.
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p. 1118 - 1133
(2007/10/03)
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- Oxidation of Sulfides to Sulfoxides with Hypervalent (tert-Butylperoxy)iodanes
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Oxidation of sulfides with the crystalline (alkylperoxy)iodanes, 1-(tert-butylperoxy)-1,2-benziodoxol-3(1H)-ones 2a and 2b, in acetonitrile-water or in dichloromethane, affords sulfoxides in high yields. Measurement of the relative rates of oxidation for a series of ring-substituted thioanisoles 3b (p-MeO), 3c (p-Me), and 3d (p-Cl) in acetonitrile-water indicates that electron-releasing groups such as p-MeO and p-Me groups increase the rate of oxidation, and Hammett correlation of the relative rate factors with the substituent constants affords the reaction constants ρ+ = -2.23 (σ+, r = 0.98) for BF3-catalyzed oxidation and ρ = -3.32 (σ, r = 0.98) for uncatalyzed oxidation. The effects of a free-radical scavenger, galvinoxyl, were examined. A mechanism involving the intermediary formation of the sulfonium species 11 by nucleophilic attack of sulfide toward the iodine(III) atom of 2 is proposed for the oxidation in acetonitrile-water in the presence and the absence of BF3· Et2O. On the other hand, the oxidation of sulfoxides in dichloromethane probably proceeds by a radical process, which involves the decomposition at room temperature of 2 via homolytic bond cleavage of the weak iodine(III)-peroxy bond, generating tert-butylperoxy radical and the [9-1-2] iodanyl radical 12.
- Ochiai, Masahito,Nakanishi, Akinobu,Ito, Takao
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p. 4253 - 4259
(2007/10/03)
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- Phosphadioxirane Intermediates in the Reaction of Singlet Oxygen with Phosphites and Phosphines
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Intermediates in the singlet oxygen reaction of phosphites and phosphines have been studied by trapping and tracer experiments.Trapping study with diphenyl sulfoxide revealed that the added substrate and phosphite are competing toward the same intermediate.The relative reactivity of (BuO)3P/Ph2S/Ph2SO = 300:4:1 and the negative ρ-value of -0.63 for diphenyl sulfoxides are not consistent with 1,3-dipolar phosphine peroxides, but suggest electrophilic O-transfers by cyclic phosphadioxiranes.Intermediacy of phosphadioxiranes was supported by an 18O-tracer study on the formation of rearranged diphenylphosphinate from 1O2 and triphenylphosphine.Theoretical calculations also supported the dioxirane intermediate by predicting no existence of 1,3-dipolar peroxide.
- Tsuji, Shoei,Kondo, Masaaki,Ishiguro, Katsuya,Sawaki, Yasuhiko
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p. 5055 - 5059
(2007/10/02)
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- NMR Study of Substituent Effects in 4-Substituted and 4,4'-Disubstituted Diphenyl Sulphoxides and Sulphones
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The proton and carbon NMR spectra of nine 4-X-diphenyl sulphoxides, seven 4-X-4'-NO2-diphenyl sulphoxides, eight 4,4'-X2-diphenyl sulphoxides, eight 4-X-diphenyl sulphones, seven 4-X-4'-NO2-diphenyl sulphones and eight 4,4'-X2-diphenyl sulphones have been obtained.Correlation of the 13C chemical shifts with the appropriate substituent chemical shifts (SCS) for monosubstituted benzenes (Lynch plots) does not show the enhancement of substituent effect at C-1 (para to the substituent) that was a feature of the corresponding sulphides studied earlier.Dual substituent parameter (DSP) correlations of the 13C chemical shifts with ?I/?R0 are excellent for carbons meta (C-2,6) and para (C-1) to the substituent.The trends for the series sulphides, sulphoxides, sulphones, where a decreasing response to the change of substituent is the general observation, are discussed.Changes of molecular conformation may also influence the transmission of electronic effects to the ring not carrying the variable substituent X. KEY WORDS 1H NMR 13C NMR Diphenyl sulpoxides Diphenyl sulphones Substituent effects
- Chandrasekaran, R.,Perumal, S.,Wilson, D. A.
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p. 360 - 367
(2007/10/02)
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- Thermal Decomposition of some Allyl Methoxyarenesulphinates
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The thermal decomposition of some allyl methoxyarenesulphinates in boiling acetic acid has been studied.The principal products are the diaryl sulphides together with small amounts of the aryl arenethiosulphonates, diaryl sulphoxides, diaryl sulphones, aromatic hydrocarbons, and in one case, some of the allyl aryl sulphone.
- Bell, Kevin H.
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p. 1957 - 1960
(2007/10/02)
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- TURNING THE REACTIVITY OF CARBONYL OXIDES FROM NUCLEOPHILIC TO ELECTROPHILIC. A NOVEL DEOXYGENATION OF SULFOXIDES BY ELECTROPHILIC α,α,α-TRIFLUOROACETOPHENONE O-OXIDE
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The well-known nucleophilic reactivity of carbonyl oxides could be turned into electrophilic by a potent electron-attracting group.Thus α,α,α-trifluoroacetophenone O-oxide oxidizes both sulfides and sulfoxides electrophilically, and the most characteristic reaction is the deoxyganation of sulfoxides.
- Ishiguro, Katsuya,Hirano, Yukimichi,Sawaki, Yasuhiko
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p. 6201 - 6204
(2007/10/02)
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- PHASE TRANSFER CONTROLLED SELECTIVE OXIDATION OF DIARYLSULFIDES TO DIARYLSULFOXIDES USING POTASSIUM HYDROGEN PERSULFATE
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The use of biphasic reaction conditions and a phase transfer catalyst controls the oxidation reaction of potassium hydrogen persulfate with diarylsulfides yielding predominantly sulfoxides.This is in contrast to the raction in polar solvents where sulfones are the major products.
- Evans, T. L.,Grade, M. M.
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p. 1206 - 1216
(2007/10/02)
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- Oxidation of Alkenes and Sulphoxides with a Mixture of Potassium Superoxide and Diethyl Chlorophosphate
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The reaction of potassium superoxide with diethyl chlorophosphate in the presence of 18-crown-6 ether gave at least two oxidizing agents, one of which was electrophilic and used in the oxidation of alkenes, whilst the other, nucleophilic in type, was important in the oxidation of sulphoxides.
- Miura, Masahiro,Nojima, Masatomo,Kusabayashi, Shigekazu
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p. 1352 - 1353
(2007/10/02)
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- Reactivity of Carbonyl Oxides. Characteristic Nucleophilic Oxygen Atom Transfer from R2COO beside Electrophilic and Radical Reactions
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According to a MINDO/3 calculation, carbonyl oxide H2COO has a large contribution of zwitterionic structure 1a, which is not altered by phenyl substituent.The dye-sensitized photooxidation of diazomethanes in CH2Cl2 - MeOH afforded ca. 30percent yield of α-methoxy hydroperoxides as product from 1a and MeOH.Relative reactivities of various types of substrates toward the carbonyl oxide from diazofluorene and 1O2 have been determined.While benzene gave phenol in a low yield, substituted benzenes such as toluene or anisole yielded products by hydrogen atom abstraction on the side chain as a major reaction.Olefins gave a rather minor amount of epoxides; the predominant reaction was C-C cleavage or allylic hydrogen abstraction.The realtive reactivity with carbonyl oxide is in the order Ph2SO >> Ph2S > C = C > benzene, where C = C means α-methylstyrene.This order is in sharp contrast to the case of peroxy acid, Ph2S >> Ph2SO >> C = C, or to the order with acylperoxy radical, C = C >> Ph2S, Ph2SO.The above order with carbonyl oxide indicates a nucleophilic oxygen atom transfer as a characteristic reaction; this was clearly shown by the positive ρ value of +0.26 for substituted diphenyl sulfoxides.The reactivities of various substrates revealed that another characteristic reaction is hydrogen atom abstraction as a radical, and carbonyl oxides could be regarded as a rather poor electrophilic O-transfer agent.These features may be understood by representing carbonyl oxides as a resonance hybrid of R2C=O+-O- (1a) and R2C*-O-O* (1c).
- Sawaki, Yasuhiko,Kato, Hiroshi,Ogata, Yoshiro
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p. 3832 - 3837
(2007/10/02)
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- Novel Sulfonylation reagent: Sulfuric Acid-Hexafluoroacetic Anhydride
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A mixture of sulfuric acid and hexafluoroacetic anhydride is an efficient reagent for the sulfonylation of aromatic compounds.
- Tyobeka, Themba E.,Hancock, Richard A.,Weigel, Helmut
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p. 114 - 115
(2007/10/02)
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- Process for selectively producing high-yield, high-purity 4,4-substituted diaryl sulfones
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4,4'-substituted diaryl sulfones of high yield and high purity are selectively formed by the oxidation of 4,4'-substituted diaryl sulfides and diaryl sulfoxides, respectively, employing an aqueous slurry, including a molybdic acid-peroxide-catalyzed oxidation system, the aqueous slurry being maintained at a pH of less than about one.
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