- Ni-Catalyzed Borylation of Aryl Sulfoxides
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A nickel/N-heterocyclic carbene (NHC) catalytic system has been developed for the borylation of aryl sulfoxides with B2(neop)2 (neop=neopentyl glycolato). A wide range of aryl sulfoxides with different electronic and steric properties were converted into the corresponding arylboronic esters in good yields. The regioselective borylation of unsymmetric diaryl sulfoxides was also feasible leading to borylation of the sterically less encumbered aryl substituent. Competition experiments demonstrated that an electron-deficient aryl moiety reacts preferentially. The origin of the selectivity in the Ni-catalyzed borylation of electronically biased unsymmetrical diaryl sulfoxide lies in the oxidative addition step of the catalytic cycle, as oxidative addition of methoxyphenyl 4-(trifluoromethyl)phenyl sulfoxide to the Ni(0) complex occurs selectively to give the structurally characterized complex trans-[Ni(ICy)2(4-CF3-C6H4){(SO)-4-MeO-C6H4}] 4. For complex 5, the isomer trans-[Ni(ICy)2(C6H5)(OSC6H5)] 5-I was structurally characterized in which the phenyl sulfinyl ligand is bound via the oxygen atom to nickel. In solution, the complex trans-[Ni(ICy)2(C6H5)(OSC6H5)] 5-I is in equilibrium with the S-bonded isomer trans-[Ni(ICy)2(C6H5)(SOC6H5)] 5, as shown by NMR spectroscopy. DFT calculations reveal that these isomers are separated by a mere 0.3 kJ/mol (M06/def2-TZVP-level of theory) and connected via a transition state trans-[Ni(ICy)2(C6H5)(η2-{SO}-C6H5)], which lies only 10.8 kcal/mol above 5.
- Huang, Mingming,Wu, Zhu,Krebs, Johannes,Friedrich, Alexandra,Luo, Xiaoling,Westcott, Stephen A.,Radius, Udo,Marder, Todd B.
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supporting information
p. 8149 - 8158
(2021/05/10)
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- Palladium-Catalyzed Sulfinylation of Aryl- And Alkenylborons with Sulfinate Esters
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An efficient, direct sulfinylation of organoborons catalyzed by palladium is disclosed. Treatment of organoborons and sulfinate esters in the presence of a palladium precatalyst provided a broad range of sulfoxides. Various organosulfur compounds having oxidizable functional groups were successfully prepared through the sulfoxide synthesis.
- Hosoya, Takamitsu,Kanemoto, Kazuya,Nakamura, Yu,Suzuki, Minori,Yoshida, Suguru
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supporting information
p. 3793 - 3797
(2021/05/29)
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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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- Electrochemical Thiolation and Borylation of Arylazo Sulfones with Thiols and B2pin2
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An efficient electrochemical synthesis approach of various unsymmetrical thioethers and arylboronates has been developed. Bench stable arylazo sulfones were used as radical precursors for carbon-heteroatom bond formation under electrochemical conditions. Moreover, the scalability of this approach was evaluated by performing the electrochemical thiolation and borylation of arylazo sulfones with thiols and B2pin2 on a gram scale. This protocol not only avoided the use of stoichiometric oxidants, metal catalysts, activating agents and even added bases, but also exhibited favorable functional group tolerance. (Figure presented.).
- Wang, Rongkang,Chen, Fangming,Jiang, Lvqi,Yi, Wenbin
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supporting information
p. 1904 - 1911
(2021/02/12)
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- Sulfoxide and Sulfone Synthesis via Electrochemical Oxidation of Sulfides
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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
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p. 13790 - 13799
(2021/10/12)
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- Photocatalytic Activity of Ruthenium(II) Complex with 1,10-Phenanthroline-3,8-dicarboxylic Acid in Aerobic Oxidation Reactions
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Abstract: Mixed-ligand ruthenium(II) complex with 2,2′-bipyridine and 1,10-phenanthroline-3,8-dicarboxylic acid with the composition [Ru(phen-C)(bpy)2]Cl2·5H2O (bpy = 2,2′-bipyridine, phen-C = 1,10-phenantroline-3,8-dicarboxylic acid) has been synthesized and characterized by spectral data. The complex has been tested as photocatalyst in aerobic oxidation reactions, including transformation of arylboronic acids to phenols, primary amines to imines, and sulfides to sulfoxides in aqueous medium. The possibility of regeneration of the catalyst in the oxidation of sulfides has been demonstrated.
- Abel, A. S.,Averin, A. D.,Beletskaya, I. P.,Bessmertnykh-Lemeune, A. G.,Yakushev, A. A.,Zenkov, I. S.
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p. 1398 - 1404
(2021/10/26)
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- Synthesis of an anthraquinone-containing polymeric photosensitizer and its application in aerobic photooxidation of thioethers
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Work on the synthesis of a polymeric photosensitizer and its application in the photooxidation of thioethers is reported herein. Firstly, the polymeric photosensitizer was designed and synthesized by the reaction of anthraquinone-2-carbonyl chloride (AQ-2-COCl) with poly(2-hydroxyethyl methacrylate) (PHEMA). Then, the visible light-induced photooxidation of thioethers under aerobic conditions was investigated. The results revealed that the reaction yielded sulfoxides highly chemoselectively in excellent yields with good substrate tolerance. Importantly, AQ-PHEMA could be easily recovered and reused more than 20 times without significant loss of the catalytic activity.
- Chen, Yang,Ding, Aishun,Hu, Jianhua
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p. 10661 - 10665
(2020/03/27)
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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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- Catalyst-free visible-light-initiated oxidative coupling of aryldiazo sulfones with thiols leading to unsymmetrical sulfoxides in air
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A facile and efficient visible-light-driven method has been developed to construct sulfoxides via oxidative coupling of aryldiazo sulfones with thiols using the O2 in air as the oxidant. This reaction could be performed at room temperature under catalyst- and additive-free conditions. The present methodology offers a mild and environmentally benign approach to obtain a library of sulfoxides in good yields with favorable functional group tolerance.
- Liu, Qishun,Wang, Leilei,Yue, Huilan,Li, Jiang-Sheng,Luo, Zidan,Wei, Wei
-
supporting information
p. 1609 - 1613
(2019/04/08)
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- Method for preparing visible light promoted asymmetric sulfoxide compound
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The invention belongs to the field of organic synthetic chemistry, particularly relates to a preparation method of an asymmetric sulfoxide compound, and particularly discloses a method for synthesizing the asymmetric sulfoxide compound based on visible light catalysis. A compound shown in the formula I and a compound shown in the formula II are added to a reactor, a mixture of an organic solvent and water is added as a reaction solvent, the reactor is connected to air, under the irradiation of visible light, a reaction at a room temperature is performed for 16-40 hours; and after a detection reaction of a TLC thin layer chromatography plate is completed, pure water is added, then the extraction is performed, extract liquid is combined and dried, the extract liquid is concentrated and purified to obtain a compound shown in the formula III, and the compound is the asymmetric sulfoxide compound. The reaction conditions are mild, energy is clean, a strong oxidant is not needed, the safetyof the reaction is improved, the pollution caused by using a metal reagent is avoided, and the reaction cost is saved.
- -
-
Paragraph 0031; 0032
(2019/06/11)
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- Enantioselective Synthesis of Chiral-at-Sulfur 1,2-Benzothiazines by CpxRhIII-Catalyzed C?H Functionalization of Sulfoximines
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Sulfoximines with stereogenic sulfur atoms are attractive structural motifs in drug discovery. A direct catalytic enantioselective method for the synthesis of sulfur-chiral 1,2-benzothiazines from readily accessible diaryl sulfoximines is presented. Rhodium(III) complexes equipped with chiral cyclopentadienyl ligands and paired with suitable carboxylic acid additives engage in an enantiodetermining C?H activation directed by the sulfoximine group. Subsequent trapping of the rhodacycle with a broad range of diazoketones gives access to S-chiral 1,2-benzothiazines with synthetically highly attractive substitution patterns in good yields and enantioselectivities.
- Sun, Yang,Cramer, Nicolai
-
supporting information
p. 15539 - 15543
(2018/11/02)
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- Synthesis of o-Aryloxy Triarylsulfonium Salts via Aryne Insertion into Diaryl Sulfoxides
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The aryne insertion into "S-O" bond has been validated recently. This technology is elusively applied to the synthesis of thioethers. In contrast to the reported cases, the reaction described furnished o-aryloxy triarylsulfonium salts, in lieu of thioethe
- Li, Xiaojin,Sun, Yan,Huang, Xin,Zhang, Lei,Kong, Lichun,Peng, Bo
-
supporting information
p. 838 - 841
(2017/02/26)
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- Br?nsted Acid-Mediated Hydrative Arylation of Unactivated Alkynes
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The Br?nsted acid-mediated reaction of unactivated alkynes with aryl sulfoxides leads to simultaneous hydration and intermolecular C-C bond formation. This solvent- A nd metal-free transformation directly delivers α-arylated carbonyl compounds as the prod
- Kaiser, Daniel,Veiros, Luís F.,Maulide, Nuno
-
supporting information
p. 4727 - 4732
(2016/04/05)
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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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- No-carrier-added [18F]fluoroarenes from the radiofluorination of diaryl sulfoxides
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No-carrier-added [18F]fluoroarenes were synthesized through the radiofluorination of diaryl sulfoxides with [18F]fluoride ion. Diaryl sulfoxides bearing a para electron-withdrawing substituent readily gave the corresponding 4-[18F]fluoroarenes in high RCYs. This process broadens the scope for preparing novel 18F-labeling synthons and PET radiotracers.
- Chun, Joong-Hyun,Morse, Cheryl L.,Chin, Frederick T.,Pike, Victor W.
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supporting information
p. 2151 - 2153
(2013/03/14)
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- Desymmetrization of prochiral diaryl sulfoxides by an asymmetric sulfoxide-magnesium exchange
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The first desymmetrizations of prochiral diaryl sulfoxides 1 by an asymmetric sulfoxide-magnesium exchange reaction are reported. The respective substrate (1), iPr2Mg, and the dilithium salt of (S)-BINOL (which was prepared in situ) provided (S)-configured aryl isopropyl sulfoxides 2 in up to 91 % yield and with up to 91 % ee. (S)-BINOL was re-isolable in 98 % yield. Copyright
- Hampel, Thomas,Ruppenthal, Simon,Saelinger, Daniel,Brueckner, Reinhard
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supporting information; body text
p. 3136 - 3140
(2012/05/20)
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- Efficient organic transformations mediated by ZrOCl28H 2O in Water
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Operationally simple and environmentally benign methods for some organic transformations comprising reductive coupling of sulfonyl chlorides, chemoselective deoxygenation of sulfoxides, and halogenation of alcohols mediated by ZrOCl28H2O/MX in water have been developed.
- Jafarpour, Maasoumeh,Rezaeifard, Abdolreza,Heidari, Mahdieh
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experimental part
p. 1470 - 1482
(2011/10/05)
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- Mild and efficient deoxygenation of sulfoxides to sulfides with Cp 2TiCl2/gallium system
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The Cp2TiCl2/Ga system was found to be a new reagent for reducing a variety of sulfoxides to the corresponding sulfides in good to excellent yields under mild conditions. Copyright
- Yoo, Byung Woo,Min, Sang Ki
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body text
p. 2993 - 2996
(2011/09/14)
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- Polystyrene and silica gel-supported, AlCl3-catalyzed preparation of diaryl sulfoxides from arenes and thionyl chloride
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A simple, chemoselective, and efficient method has been developed for direct conversion of arenes to symmetrical diaryl sulfoxides using thionyl chloride in the presence of a catalytic amount of cross-linked polystyrene-supported aluminium chloride (Ps-AlCl3) and silica gel-supported aluminium chloride (SiO2-AlCl3). These solid acid catalysts are stable and can be easily recovered and reused without appreciable change in their efficiency. Copyright Taylor & Francis Group, LLC.
- Boroujeni, Kaveh Parvanak
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experimental part
p. 2085 - 2091
(2010/12/19)
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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)
-
- 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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- Kinetics and mechanism of (saJen)Mnlll-catalysed hydrogen peroxide oxidation of diphenyl sulphides
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The kinetics of (salen)MIII complexes-catalysed oxidation of a few diphenyl sulphides by hydrogen peroxide have been investigated at 25°C in acetonitrile (80%) - water (20%) spectrophotometrically. The reaction follows first-order kinetics in (salen)Mn111 complex and zero-order kinetics in hydrogen peroxide. The order of the reaction with respect to .sulphide is fractional. The effects of nitrogenous bases, free radical inhibitor and changes in solvent composition have also been studied. A suitable mechanism involving a manganese(III)-hydroperoxide complex as reactive species has been proposed.
- Chellamani,Alhaji
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experimental part
p. 346 - 351
(2010/01/16)
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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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- Mild and efficient deoxygenation of sulfoxides with MoCl5/indium system
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It has been demonstrated that dialkyl, diaryl, and aryl alkyl sulfoxides can be efficiently converted into the corresponding sulfides by the reaction with a MoCl5/In system in good to excellent yields under mild conditions. Copyright Taylor & Francis Group, LLC.
- Yoo, Byung Woo,Song, Min Suk,Park, Min Chol
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p. 3089 - 3093
(2008/02/12)
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- Lithium/Sodium Perchlorate Catalyzed Synthesis of Symmetrical Diaryl Sulfoxides
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Synthesis of diaryl sulfoxides from aromatics and thionyl chloride catalyzed by LiClO4/NaClO4 at room temperature is described. Mild reaction conditions, simple work-up, inexpensive and easily available catalysts are important and attractive features of this method.
- Bandgar,Makone
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p. 743 - 750
(2007/10/03)
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- Dinitrogen Tetroxide Impregnated Activated Charcoal (N2O 4/Charcoal): Selective Oxidation of Sulfides to Sulfoxides and Bisulfides to Thiosulfonates
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Dinitrogen tetroxide was easily impregnated on activated charcoal to give a stable heterogeneous reagent (N2O4/charcoal). The chemoselective oxidation of sulfides to sulfoxides in the presence of different sensitive functional groups was achieved using this reagent in CH 2Cl2 at room temperature. Dialkyl sulfides were also selectively converted to their corresponding sulfoxides in the presence of diaryl or alkyl-aryl sulfides. Oxidation of disulfides to thiosulfonates without any over oxidation was also performed at room temperature by this system.
- Iranpoor, Nasser,Firouzabadi, Habib,Pourali, Ali-Reza
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p. 347 - 349
(2007/10/03)
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- Highly Rapid and Direct Synthesis of Diaryl Sulfoxides
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Aromatic compounds react smoothly with thionyl chloride in the presence of 10 mol% of water at ambient temperature to afford the corresponding symmetrical diaryl sulfoxides in good to excellent yields with high regioselectivity.
- Bandgar,Kinkar,Kamble,Bettigeri
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p. 2029 - 2032
(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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- A General and Expeditious One-Pot Synthesis of Sulfoxides in High Optical Purity from Norephedrine-Derived Sulfamidites
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A general and simple procedure for preparing any kind of enantiomerically enriched sulfoxide starting from norephedrine-derived N-benzyloxycarbonylsulfamidite 3a is reported. After one-pot reaction of 3a with RMgX, HBF4, and R'MgX, a variety of sulfoxides 6 are obtained in ee usually higher than 93% and isolated yields ranging between 50 and 78%. The obtained configuration is tunable by simply electing the order of the addition of the reagents.
- Ruano, Jose L. Garcia,Alemparte, Carlos,Aranda, M. Teresa,Zarzuelo, Maria M.
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- Scandium triflate catalyzed one-pot synthesis of diaryl sulfoxides
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Arenes react smoothly with thionyl chloride in the presence of a catalytic amount of scandium triflate at ambient temperature to afford the corresponding symmetrical diaryl sulfoxides in excellent yields with high regioselectivity.
- Yadav, Jhillu S.,Reddy, Basi V. Subba,Rao, R. Srinivasa,Kumar, S. Praveen,Nagaiah
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p. 784 - 786
(2007/10/03)
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- Electrophilic oxidant produced in the photodeoxygenation of 1,2-benzodiphenylene sulfoxide
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We report that the photodeoxygenation of 1,2-benzodiphenylene sulfoxide, 1, generates an intermediate capable of oxidizing the solvent benzene to phenol. The reactivity of the intermediate was probed with various substrates (2-methylbutane, chloride ion,
- Lucien,Greer
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p. 4576 - 4579
(2007/10/03)
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- Trifluoromethanesulfonic acid catalyzed preparation of symmetrical diaryl sulfoxides from arenes and thionyl chloride
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The preparation of symmetrical diaryl sulfoxides from thionyl chloride and arenes catalyzed by trifluoromethanesulfonic acid is described. The reaction is characterized by its mildness, high yields, selectivity, and ease of workup.
- Olah, George A.,Marinez, Eric R.,Prakash, G. K. Surya
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p. 1397 - 1398
(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)
-
- Extremely Facile Ligand-Exchange and Disproportionation Reactions of Diaryl Sulfoxides, Selenoxides, and Triarylphosphine Oxides with Organolithium and Grignard Reagents
-
Diaryl sulfoxides undergo unusually rapid ligand-exchange reaction upon treatment with organolithium reagents at -95 deg C.Optically pure phenyl p-tolyl sulfoxide (4b) reacted with organolithium reagents at the range from -20 to -95 deg C to give facile ligand-exchange and disproportionation products, i.e., diphenyl sulfoxide (7), recovered 4b, and di-p-tolyl sulfoxide (8) in a statistical ratio of 1:2:1 in quantitative yields, and the recovered 4b was completely racemized.This facile ligand exchange was observed in the similar reactions using only diaryl selenoxides and triarylphosphine oxides.The reactions of 18O-labeled phenyl p-tolyl sulfoxide (4c) with organolithium reagents gave products in a statistical ration without 18O scrambling, indicating that only the C-S bond cleavage took place under low temperature.It is suggested that the ligand exchange reactions occur by the nucleophilic attack by organolithium reagent at the sulfinyl sulfur atom, giving ?-sulfurane as an intermediate that collapses rapidly.These results suggest that the treatment of arylic sulfoxides, selenoxides, and phosphine oxides with strong bases should be effected with caution.
- Furukawa, Naomichi,Ogawa, Satoshi,Matsumura, Kazunori,Fujihara, Hisashi
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p. 6341 - 6348
(2007/10/02)
-
- A General Procedure for the Selective Oxidation of Sulfides to Sulfoxides by Nitric Acid: Tetrabromoaurate(III) Catalyst in a Biphasic System
-
Tetrabromoaurate(III) is an efficient catalyst for the oxidation of sulfides to sulfoxides by nitric acid in a biphasic system (nitromethane/water).The system is selective and can be applied to the oxidation of any type of dialkyl and alkyl aryl sulfide and also of diaryl sulfides activated by electron-releasing substituents.The nature of the active species has been investigated in relation to the mechanistic aspects.
- Gasparrini, Francesco,Giovannoli, Mario,Misiti, Domenico,Natile, Giovanni,Palmieri, Gianni
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p. 1323 - 1328
(2007/10/02)
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- Selectivity in the TiO2-mediated photocatalytic oxidation of thioethers
-
The relative rates of photooxygenation of substituted diphenyl sulfides on irradiated TiO2 powders suspended in oxygenated acetonitrile correlate linearly with σ+, as is consistent with formation of a surface bound cation radical in the primary photoprocess. Substituted dibenzyl sulfides, in contrast, suffer C-S cleavage upon photocatalyzed oxidation. Factors disposing these reactions toward preferential sulfoxide formation or bond cleavage are discussed.
- Fox,Abdel-Wahab
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p. 4533 - 4536
(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
-
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)
-