- COMPOSITES, METHODS AND USES THEREOF
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The present invention relates, in general terms, to methods of catalysing a reaction, including the steps of contacting a chemical entity comprising a sulphide moiety with a composite and an oxidant. The composite acts as a heterogeneous catalyst to oxidise the sulphide moiety. The present invention also relates to composites, methods of synthesising the composites and its use as a catalyst thereof.
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Page/Page column 26
(2021/06/04)
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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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- Flow Electrosynthesis of Sulfoxides, Sulfones, and Sulfoximines without Supporting Electrolytes
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An efficient electrochemical flow process for the selective oxidation of sulfides to sulfoxides and sulfones and of sulfoxides toN-cyanosulfoximines has been developed. In total, 69 examples of sulfoxides, sulfones, andN-cyanosulfoximines have been synthesized in good to excellent yields and with high current efficiencies. The synthesis was assisted and facilitated through a supporting electrolyte-free, fully automated electrochemical protocol that highlights the advantages of flow electrolysis.
- Amri, Nasser,Wirth, Thomas
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p. 15961 - 15972
(2021/07/20)
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- 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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- Selective oxidation of (hetero)sulfides with molecular oxygen under clean conditions
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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
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supporting information
p. 433 - 438
(2020/02/13)
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- Selectivity switch in the aerobic oxygenation of sulfides photocatalysed by visible-light-responsive decavanadate
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Nanometre-sized metal oxides are promising species for the development of visible-light-responsive photocatalysts for the selective transformation of organic functional groups. In this article, we report that decavanadate ([V10O28]6-, V10) behaved as an efficient visible-light-responsive photocatalyst in the product-selective oxygenation of sulfides achieved using O2 (1 atm) as the green oxidant. In particular, we revealed that visible-light-responsive photocatalysis of V10 showed remarkable activity for the oxygenation of structurally diverse sulfides to form the corresponding sulfones using O2 in methyl ethyl ketone (MEK). Furthermore, by simply adding water to the reaction mixture, the product selectivity of sulfide oxygenation can be significantly switched toward the production of sulfoxides, without concomitant loss of photocatalytic activity. Based on experimental evidence, we inferred the following mechanistic steps for this photocatalytic system: the aerobic oxygenation of sulfides to form the corresponding sulfoxides initiated by a visible-light-induced photoredox reaction of V10. As for the formation of sulfones, MEK-derived peroxide species as the co-catalysts are probably involved in the oxygenation of sulfoxides to sulfones. The selectivity switch of the V10-photocatalysed reaction brought about by water addition is most likely achieved by suppressing the formation of MEK-derived peroxide species. This journal is
- Li, Chifeng,Mizuno, Noritaka,Murata, Kei,Ishii, Kazuyuki,Suenobu, Tomoyoshi,Yamaguchi, Kazuya,Suzuki, Kosuke
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supporting information
p. 3896 - 3905
(2020/07/09)
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- Sulfoxide and sulfone compounds, as well as selective synthesis method and application thereof
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The invention discloses a method for selectively synthesizing a sulfoxide compound shown as a formula (II) and a sulfone compound shown as a formula (III). In a reaction solvent, thioether (I) is usedas a reaction raw material and oxygen as an oxidation reagent, under the catalytic action of visible light and a photosensitive reagent; under the assistance of an additive, when a large-polarity proton-containing additive such as an acid and an alcohol or a solvent or an additive with excellent electron donating ability is used, a sulfoxide compound (II) is selectively generated; and when a small-polarity aprotic additive or a solvent is used, a sulfone compound (III) is selectively generated. The synthesis method has the advantages of easily available and cheap raw materials, simple reaction operation, mild reaction conditions, high yield and excellent functional group tolerance. According to the invention, synthesis and modification of some medicines are realized, and an efficient method for selectively constructing sulfoxide and sulfone compounds is provided for medicinal chemistry research.
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Paragraph 0049-0052; 0113-0116
(2019/12/02)
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- Selective Late-Stage Oxygenation of Sulfides with Ground-State Oxygen by Uranyl Photocatalysis
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Oxygenation is a fundamental transformation in synthesis. Herein, we describe the selective late-stage oxygenation of sulfur-containing complex molecules with ground-state oxygen under ambient conditions. The high oxidation potential of the active uranyl cation (UO22+) enabled the efficient synthesis of sulfones. The ligand-to-metal charge transfer process (LMCT) from O 2p to U 5f within the O=U=O group, which generates a UV center and an oxygen radical, is assumed to be affected by the solvent and additives, and can be tuned to promote selective sulfoxidation. This tunable strategy enabled the batch synthesis of 32 pharmaceuticals and analogues by late-stage oxygenation in an atom- and step-efficient manner.
- Li, Yiming,Rizvi, S. Aal-e-Ali,Hu, Deqing,Sun, Danwen,Gao, Anhui,Zhou, Yubo,Li, Jia,Jiang, Xuefeng
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supporting information
p. 13499 - 13506
(2019/08/21)
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- Controlled α-mono- and α,α-di-halogenation of alkyl sulfones using reagent-solvent halogen bonding
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The direct and selective α-mono-bromination of alkyl sulfones was achieved through base-mediated electrophilic halogenation. The appropriate combination of solvent and electrophilic bromine source was found to be critical to control the nature of the products formed, where reagent-solvent halogen bonding is proposed to control the selectivity via alteration of the effective size of the electrophilic bromine source. Conversely, the α,α-di-brominated sulfones were selectively obtained in good yields following polyhalogenation followed by selective de-halogenation during workup. Both procedures can be applied on gram scale, and the mono-halogenation was successfully extended to the fully selective α-chlorination, α-iodination and α-fluorination of alkyl sulfones.
- Poteat, Christopher M.,Lindsay, Vincent N. G.
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supporting information
p. 2912 - 2915
(2019/03/17)
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- Switchable Synthesis of Aryl Sulfones and Sulfoxides through Solvent-Promoted Oxidation of Sulfides with O2/Air
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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
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supporting information
p. 8925 - 8929
(2019/11/14)
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- Synthesis of difluoromethylated 2-oxindoles and quinoline-2,4-diones via visible light-induced tandem radical cyclization of N -arylacrylamides
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Visible light-induced difluoromethylation of N-arylacrylamides to afford difluoromethylated 2-oxindoles and quinoline-2,4-diones with difluoromethyl 2-pyridyl sulfones as radical precursors has been disclosed. This method provides convenient access to a v
- Sun, Huan,Jiang, Yue,Yang, Ying-Sha,Li, Yun-Yun,Li, Lin,Wang, Wen-Xuan,Feng, Tao,Li, Zheng-Hui,Liu, Ji-Kai
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supporting information
p. 6629 - 6638
(2019/07/16)
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- Ultrasonic-assisted green synthetic method for 2-sulfonyl pyridine derivatives
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The invention discloses an ultrasonic-assisted green synthetic method for 2-sulfonyl pyridine derivatives. The 2-sulfonyl pyridine derivatives are synthesized from 2-halogenated pyridine compounds, sulfonyl chloride compounds and sulfite by one-pot reaction in an aqueous solution under the ultrasonic-assisted action. The raw materials are easily available, the reaction conditions are simple, mild,green and energy-saving, the reaction selectivity and yield are high, and compatibility of substrate functional groups is excellent; particularly, the 2-sulfonyl pyridine derivatives can be obtainedby filtering and direct separation, production cost is reduced, the problem of environmental pollution of the traditional method is solved, and the method has higher application value.
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Paragraph 0098-0104
(2019/01/16)
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- A Class of Amide Ligands Enable Cu-Catalyzed Coupling of (Hetero)aryl Halides with Sulfinic Acid Salts under Mild Conditions
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The amide derived from 4-hydroxy-l-proline and 2,6-dimethylaniline is a powerful ligand for Cu-catalyzed coupling of (hetero)aryl halides with sulfinic acid salts, allowing the formation of a wide range of (hetero)aryl sulfones from the corresponding (hetero)aryl halides at considerably low catalytic loadings. The coupling of (hetero)aryl iodides and sodium methanesulfinate proceeds at room temperature with only 0.5 mol % CuI and ligand, representing the first example for Cu-catalyzed arylation at both low catalytic loading and room temperature.
- Zhao, Jinlong,Niu, Songtao,Jiang, Xi,Jiang, Yongwen,Zhang, Xiaojing,Sun, Tiemin,Ma, Dawei
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p. 6589 - 6599
(2018/05/31)
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- Oxidative kinetic resolution of heterocyclic sulfoxides with a porphyrin-inspired manganese complex by hydrogen peroxide
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We have successfully reported here the low loading porphyrin-inspired high-valent manganese (IV)-oxo complex was applied in oxidative kinetic resolution (OKR) of racemic heterocyclic sulfoxides using the environmentally benign hydrogen peroxide for the first time. This approach allows for rapid OKR (0.5 h) of a variety of racemic sulfoxides (including pyridine, pyrimidine, pyrazine, thiazole, benzothiazole, thiophene) in excellent enantioselectivity (up to > 99% ee), simultaneously generating the corresponding sulfones in high yield (up to 80%). The catalytic system also showed an unexceptionable chemoselectivity for the sulfoxide substrates with hydroxyl groups in which only the sulfoxide group was oxidized. The practical utility of the method has been demonstrated in the OKR of gram-scale sulfoxides.
- Yang, Jinchuang,Wang, Lianyue,Lv, Ying,Li, Ning,An, Yue,Gao, Shuang
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supporting information
p. 156 - 159
(2017/12/15)
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- Process for the Synthesis of Sulfones and Sulfonamides
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A one pot single step process is described for the synthesis of a compound, including a labeled compound, containing a sulfonyl functional group comprising the step of mixing together a silane, an SO2 source, an electrophilic compound, an activ
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Paragraph 0268; 0269; 0270; 0271; 0272
(2017/07/06)
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- An environmentally benign and selective electrochemical oxidation of sulfides and thiols in a continuous-flow microreactor
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A practical and environmentally benign electrochemical oxidation of thioethers and thiols in a commercially-available continuous-flow microreactor is presented. Water is used as the source of oxygen to enable the oxidation process. The oxidation reaction utilizes the same reagents in all scenarios and the selectivity is solely governed by the applied potential. The procedure exhibits a broad scope and good functional group compatibility providing access to various sulfoxides (15 examples), sulfones (15 examples) and disulfides (6 examples). The use of continuous flow allows the optimal reaction parameters (e.g. residence time, applied voltage) to be rapidly assessed, to avoid mass- and heat-transfer limitations and to scale the electrochemistry.
- Laudadio, Gabriele,Straathof, Natan J. W.,Lanting, Menno D.,Knoops, Benny,Hessel, Volker,No?l, Timothy
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supporting information
p. 4061 - 4066
(2017/09/07)
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- Sulfone compound (by machine translation)
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[Problem] to safely and conveniently, highly selective, sulfide compound producing a sulfone compound. [Solution] pH is 9 - 12 under, water or water-insoluble solvent or an aromatic hydrocarbon-based solvent mixture, sodium hypochlorite is used as oxidizing agent, (1) (2) from the compound represented by the formula sulfide sulfone compound represented by the formula manufacturing method. (R1 And R2 Are each independently an alkyl, aryl, aralkyl, heteroaryl)[Drawing] no (by machine translation)
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Paragraph 0034; 0035
(2017/10/06)
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- Synthesis of Aromatic Sulfones from SO2 and Organosilanes Under Metal-free Conditions
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The conversion of SO2 into arylsulfones under metal-free conditions was achieved for the first time by reacting SO2 with (hetero)arylsilanes and alkylhalides in the presence of a fluoride source. The mechanism of this transformation was elucidated based on DFT calculations, which highlight the influence of SO2 in promoting C?Si bond cleavage.
- von Wolff, Niklas,Char, Jo?lle,Frogneux, Xavier,Cantat, Thibault
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supporting information
p. 5616 - 5619
(2017/05/05)
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- Selective Synthesis of Sulfoxides through Oxidation of Sulfides with Sodium Hypochlorite Pentahydrate Crystals
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Oxidation of sulfides with sodium hypochlorite pentahydrate crystals (1.1 equiv) in an aqueous acetonitrile solution selectively produces the corresponding sulfoxides in high yields. This procedure is catalyst-free and environmentally benign.
- Okada, Tomohide,Matsumuro, Hiroaki,Kitagawa, Saori,Iwai, Toshiaki,Yamazaki, Kento,Kinoshita, Yukari,Kimura, Yoshikazu,Kirihara, Masayuki
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p. 2547 - 2552
(2015/11/16)
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- Selective hydrogen peroxide oxidation of sulfides to sulfoxides or sulfones with MWW-type titanosilicate zeolite catalyst under organic solvent-free conditions
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Selective oxidation of sulfides to sulfoxides and sulfones with hydrogen peroxide under organic solvent-free conditions was demonstrated by the MWW-type titanosilicate zeolite catalyst. Sulfides were oxidized smoothly to give sulfoxides with good selectivities at ambient temperature using 1.0-1.2 equiv of hydrogen peroxide with the MWW-type titanosilicate zeolite catalyst. Especially, the Ti-MWW with an interlayer-expanded structure (Ti-IEZ-MWW) catalyst showed high activity with good chemoselectivity for the oxidation of various sulfides. The catalyst is recyclable for at least five cycles, and the only byproduct is water. Sulfides were directly oxidized to give sulfones in high yields by 2.5 equiv of hydrogen peroxide with the MWW-type titanosilicate zeolite catalyst under organic solvent-free conditions.
- Kon, Yoshihiro,Yokoi, Toshiyuki,Yoshioka, Masato,Tanaka, Shinji,Uesaka, Yumiko,Mochizuki, Takehisa,Sato, Kazuhiko,Tatsumi, Takashi
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p. 7584 - 7592
(2014/12/10)
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- Palladium-catalyzed sulfination of aryl and heteroaryl halides: Direct access to sulfones and sulfonamides
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A novel palladium-catalyzed sulfination of aryl and heteroaryl halides is described. This reaction operates under mild conditions and provides access to a wide range of aryl and heteroaryl sulfinates, a useful and versatile class of synthetic intermediates. Capitalizing on this sulfination reaction, one-pot protocols allowing direct access to sulfones and sulfonamides have also been developed. The practicality of these transformations is illustrated with the parallel synthesis of analogues of the drug Viagra.
- Shavnya, Andrei,Coffey, Steven B.,Smith, Aaron C.,Mascitti, Vincent
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supporting information
p. 6226 - 6229
(2014/01/17)
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- Highly atom-economic, catalyst- and solvent-free oxidation of sulfides into sulfones using 30% aqueous H2O2
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Highly atom-efficient oxidation of sulfides into sulfones under solvent- and catalyst-free reaction conditions using a 30% aqueous solution of H 2O2 at 75 °C is reported. A structurally diverse set of phenyl alkyl-, phenyl benzyl-, benzyl alkyl-, dialkyl-, heteroaryl alkyl- and cyclic sulfides were transformed into sulfones regardless of the aggregate state and electronic nature of the substituents. In spite of the heterogeneous reaction mixtures throughout the work, no difficulties with stirring and reaction progress were noted. In numerous cases, only 10 mol% excess of H 2O2 was used, thus contributing considerably to the high atom economy of the process. Some solid substrates required a variable excess of hydrogen peroxide; however, the reactions were performed strictly without organic solvents. The transformation was demonstrated to be amenable for scale-up with both liquid and solid sulfides. In addition, isolation and purification of the crude products can be simply done with only filtration and crystallization.
- Jereb, Marjan
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supporting information
p. 3047 - 3052,6
(2020/09/16)
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- Catalytic asymmetric conjugate addition of dialkylzinc reagents to α,β-unsaturated sulfones
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An efficient method is reported for the highly enantioselective copper-catalyzed conjugate addition of dialkylzinc reagents to α,β-unsaturated sulfones using a monodentate phosphoramidite ligand. The Royal Society of Chemistry 2010.
- Bos, Pieter H.,Macia, Beatriz,Angeles Fernandez-Ibanez,Minnaard, Adriaan J.,Feringa, Ben L.
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supporting information; experimental part
p. 47 - 49
(2010/05/19)
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- Enzymatic synthesis of novel chiral sulfoxides employing Baeyer-villiger monooxygenases
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Optically active sulfoxides are compounds of high interest in organic chemistry. Herein, we report the preparation of a set of chiral heteroaryl alkyl, cyclohexyl alkyl, and alkyl alkyl sulfoxides by using enantioselective sulfoxidation reactions employing three Baeyer-Villiger monooxygenases (BVMOs). Careful selection of the reaction conditions, starting sulfide, and biocatalyst can be used to achieve good to excellent enantiomeric excess values. Thus, valuable chiral synthons can be obtained by performing the reactions under mild and environmentally friendly conditions. The most promising biotransformations that employ a BVMO cell-free extract preparation have been developed on a 250-mg scale to give the chiral sulfoxides in high yields in most of the reactions. Copyright
- Rioz-Martinez, Ana,De Gonzalo, Gonzalo,Pazmino, Daniel E. Torres,Fraaije, Marco W.,Gotor, Vicente
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experimental part
p. 6409 - 6416
(2011/02/24)
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- Imide-catalyzed oxidation system: Sulfides to sulfoxides and sulfones
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R1SR2 Imide(cat.), → Toulene or DME R 1SOR2 R1SO2R2 A new combination system, the oxidation of sulfides using aqueous NaOCl in the presence of a catalytic amount of imide under two-phase conditions, has been developed. The combination effectively converts various sulfides to the corresponding sulfoxides and sulfones. It was deduced that the imide could react with NaOCl to produce N-chloroimide, which would play roles of both the active oxidizing reagent and phase transfer catalyst.
- Fukuda, Naohiro,Ikemoto, Tomomi
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experimental part
p. 4629 - 4631
(2010/09/17)
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- Catalytic asymmetric conjugate addition of Grignard reagents to α,β-unsaturated sulfones
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(Chemical Equation Presented) A highly efficient method is reported for the asymmetric conjugate addition of Grignard reagents to α,β- unsaturated 2-pyridylsulfones. Using a Cu/TolBinap complex, excellent enantioselectivities and high yields are obtained
- Bos, Pieter H.,Minnaard, Adriaan J.,Feringa, Ben L.
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supporting information; experimental part
p. 4219 - 4222
(2009/06/06)
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- PROCESS FOR THE PRODUCTION OF ORGANIC OXIDES
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The present invention provides a method for producing an organic oxide, wherein a substrate is oxidized using hypohalous acid, hypohalous acid salt, chlorine, bromine or iodine in the presence of water and a catalytic amount of a compound represented by the following formula (I): R1-X1-NY-R2, wherein: X1 represents -CO- or -SO2-; Y represents a hydrogen atom, a potassium atom, a sodium atom, a chlorine atom, a bromine atom or an iodine atom; R1 represents a substituted or unsubstituted hydrocarbon group, -NYR3 group or -OR3 group (in the formulae, R3 represents a substituted or unsubstituted hydrocarbon group, and Y represents the same meaning as defined above); and R2 represents a hydrogen atom or -CO-R4 group (in the formula, R4 represents a substituted or unsubstituted hydrocarbon group, -NYR5 group or -OR5 group (in the formulae, R5 represents a substituted or unsubstituted hydrocarbon group, and Y represents the same meaning as defined above)); or R1 and R4 may bind to each other to form a further substituted or unsubstituted nitrogen-containing heterocyclic ring.
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Page/Page column 14
(2009/01/24)
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- Catalytic asymmetric conjugate reduction of β,β-disubstituted α,β-unsaturated sulfones
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(Chemical Equation Presented) Access to a chiral sulfone: Asymmetric conjugate reduction of β,β-disubstituted α,β-unsaturated 2-pyridylsulfones with silanes under CuI/binap catalysis provides chiral sulfones with excellent chemical yields and e
- Llamas, Tomas,Arrayas, Ramon Gomez,Carretero, Juan C.
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p. 3329 - 3332
(2008/03/12)
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- Oxidation of aromatic lithium thiolates into sulfinate salts: An attractive entry to aryl sulfones labeled with carbon-11
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Aromatic 11C-sulfones were synthesized by S alkylation of lithium arenesulfinates, which are readily available from the corresponding thiols by an oxaziridine-mediated oxidation reaction with [11C]alkyl iodides in THF/H2O (4:1) at 150 °C. The radiosyntheses, including purification by HPLC, were completed in an average of 35 min from the end of the bombardment with 55-76% overall radiochemical yields (decay corrected). The described procedure extends the range of accessible labeling methods.
- Martin, Claudie,Sandrinelli, Franck,Perrio, Cecile,Perrio, Stephane,Lasne, Marie-Claire
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p. 210 - 214
(2007/10/03)
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- Enantioselective construction of stereogenic quaternary centres via Rh-catalyzed asymmetric addition of alkenylboronic acids to α,β- unsaturated pyridylsulfones
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The highly enantioselective construction of all-carbon quaternary stereogenic centres via Rh-catalyzed Chiraphos-mediated conjugate addition of alkenylboronic acids to β,β-disubstituted α,β-unsaturated 2-pyridylsulfones is described. The Royal Society of
- Mauleon, Pablo,Carretero, Juan C.
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p. 4961 - 4963
(2007/10/03)
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- Azetidine derivatives, their preparation and pharmaceutical compositions containing them
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Compounds of formula: in which R represents a CR1R2, C═C(R5)SO2R6 or C═C(R7)SO2alk radical, their preparation and the pharmaceutical compositions containing them.
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- Stereochemistry of direct olefin formation from carbonyl compounds and lithiated heterocyclic sulfones
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The conditions for the title reaction were studied for the 2-benzothiazole and 2-pyridine series and for some examples in the 2-pyrimidine series.The olefin preparations were generally observed to be more efficient for 2-BT-sulfone systems.From the data of the hundred cases studied, it can be concluded that (E)-olefins are obtained: (i) from saturated BT-sulfones and aromatic aldehydes; and (ii) from benzylic BT-sulfones and branched saturated aldehydes (isobutyraldehyde, pivalaldehyde) or α,β-ethylenic or aromatic aldehydes. (Z)-olefins arise: (i) fom propargylic BT-sulfones and saturated or aromatic aldehydes; and (ii) from allylic or benzylic Pyr-sulfones and saturated aldehydes.Possible mechanisms for this new olefination procedure were examined. - heteroaromatic sulfones, organolithium derivatives, intramolecular ipso reactions, stereochemistry, elimination, olefination.
- Baudin, J. B.,Hareau, G.,Julia, S. A.,Lorne, R.,Ruel, O.
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p. 856 - 878
(2007/10/02)
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- Sulphoxide Substituted Pyridines as Phase-transfer Catalysts for Nucleophilic Displacements and Alkylations
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2-Methylsulphinyl-, 2-methylsulphinylmethyl-, 2,6-bis(methylsulphinyl)-, 2,6-bis(methylsulphinylmethyl)-pyridines, bis(2-pyridylmethyl)sulphoxide, and 2-methylsulphinylpyridine N-oxide have been prepared.These sulphoxides served as good phase-transfer catalysts which accelerate SN2 type displacements of octyl bromide with various nucleophiles (thiolate, cyanide, thiocyanate, and phenoxide) in solid-liquid two-phase systems.Alkylations of phenylacetonitrile and benzyl methyl ketone with alkyl halides were also carried out in liquid-liquid two-phase systems in the presence of the above sulphoxides to afford the corresponding monoalkylated products in high yields.Pyridine derivatives bearing polysulphinyl groups were found to be even more effective catalysts for these two-phase alkylations.Neither 2-methylthio- nor 2-methylsulphonyl-pyridine catalysed SN2 type displacement reactions effectively.
- Furukawa, Naomichi,Ogawa, Satoshi,Kawai, Tsutomu,Oae, Shigeru
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p. 1833 - 1838
(2007/10/02)
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- ipso-Substitution of a Sulphinyl or Sulphonyl Group Attached to Pyridine Rings and its Application for the Synthesis of Macrocycles
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A sulphinyl or sulphonyl group directly bound to the 2- or 4-position of a pyridine ring was readily displaced by several nucleophiles such as RO-, RS-, and CN- to afford the corresponding ipso-substitution products.Similarly, 2-halogeno-6-methylsulphinyl- or -methylsulphonyl-pyridines also react with nuclephiles to afford 2-halogeno-6-substituted pyridine derivatives.Thus, the leaving abilities of the leaving groups fall in the order RSO2 > RSO > Br ca.Cl >> RS (R = alkyl or benzyl).The ipso-substitution can be applied to the synthesis of 2,6-disubstituted pyridino macrocycles containing both carbon-oxygen and carbon-sulphur bridges, resulting in several new macrocycles in moderate yields.
- Furukawa, Naomichi,Ogawa, Satoshi,Kawai, Tsutomu,Oae, Shigeru
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p. 1839 - 1845
(2007/10/02)
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