- Base-Mediated Radical Borylation of Alkyl Sulfones
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A practical and direct method was developed for the production of versatile alkyl boronate esters via transition metal-free borylation of primary and secondary alkyl sulfones. The key to the success of the strategy is the use of bis(neopentyl glycolato) diboron (B2neop2), with a stoichiometric amount of base as a promoter. The practicality and industrial potential of this protocol are highlighted by its wide functional group tolerance, the late-stage modification of complex compounds, no need for further transesterification, and operational simplicity. Radical clock, radical trap experiments, and EPR studies were conducted which show that the borylation process involves radical intermediates.
- Huang, Mingming,Hu, Jiefeng,Krummenacher, Ivo,Friedrich, Alexandra,Braunschweig, Holger,Westcott, Stephen A.,Radius, Udo,Marder, Todd B.
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- Synthesis of Sulfones and Sulfonyl Derivatives using Sodium (tert-butyldimethylsilyl)oxymethanesulfinate
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The present invention relates to a method for manufacturing a sulfone and sulfonyl derivative compound using sodium (tert-butyldimethylsilyl)oxymethanesulfinate, which is a novel organic sulfin salt, wherein the novel organic sulfin salt has good stability, environmental friendliness and economy, and is easy to handle, and thus significantly reduces the amount of transition metal catalysts and the amount of organic sulfin salts used when introducing aryl or alkenyl. Also, alkylation, arylation, amination, and fluorination are all possible during secondary functionalization. Therefore, the present invention can be usefully used in preparation and mass production of various kinds of sulfones and derivatives thereof including asymmetric sulfone derivatives.
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Paragraph 0836-0841; 0843; 0845-0846; 0848-0851; 0868-0871
(2021/04/29)
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- Silyloxymethanesulfinate as a sulfoxylate equivalent for the modular synthesis of sulfones and sulfonyl derivatives
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An efficient protocol for the modular synthesis of sulfones and sulfonyl derivatives has been developed utilizing sodium tert-butyldimethylsilyloxymethanesulfinate (TBSOMS-Na) as a sulfoxylate (SO22-) equivalent. TBSOMS-Na, easily prepared from the commercial reagents Rongalite and TBSCl, serves as a potent nucleophile in S-alkylation and Cu-catalyzed S-arylation reactions with alkyl and aryl electrophiles. The sulfone products thus obtained can undergo the second bond formation at the sulfur center with various electrophiles without a separate unmasking step to afford sulfones and sulfonyl derivatives such as sulfonamides and sulfonyl fluorides.
- Kim, Dae-Kwon,Um, Hyun-Suk,Park, Hoyoon,Kim, Seonwoo,Choi, Jin,Lee, Chulbom
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p. 13071 - 13078
(2021/01/09)
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- PhI(OAc)2-mediated decomposition of N-arylsulfonyl hydrazones: metal-free synthesis of (E)-vinyl sulfones
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A novel and efficient approach for the preparing of (E)-vinyl sulfones via PhI(OAc)2-mediated decomposition of ketone-derived N-arylsulfonyl hydrazones has been developed. The generation of α- or β-substituted vinyl sulfones was affected by the
- Luo, Zaigang,Fang, Yuyu,Zhao, Yu,Xu, Xuemei,Feng, Chengtao,Li, Zhong,Zhang, Xiaomei,He, Jie
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supporting information
p. 4105 - 4108
(2016/08/18)
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- Lithium-titanium exchange of tertiary α-sulfonyl carbanions: Synthesis, structure, dynamics and reactivity of bis(1-sulfonylalkyl) titaniums
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Lithium-titanium exchange of tertiary α-sulfonyl carbanions with ClTi(OiPr)3 and Cl2Ti(OiPr)2 in diethyl ether gave bis(1-sulfonylalkyl) titaniums and not the corresponding (1-sulfon-ylalkyl) titaniums. X-ray crystal structure analysis of di(iso-propoxy) bis[1-(phenylsulfonyl) cyclobutyl]titanium and di-(isopropoxy) bis[1-(phenylsulfonyl) isopropyl]titanium showed asymmetric distorted octahedral complexes, having hexaco-ordinate Ti atoms, two C-Ti bonds, four Ti-O bonds, and two four-membered Ti-O-S-Cα rings. According to 1H NMR spectroscopy bis(1-sulfonylcycloalkyl) titaniums are non-flux-ional at room temperature. This suggests that chiral bis(1-sulfonylalkyl) titaniums should be configurationally stable. The bis(1-sulfonylalkyl) titaniums are stable at room temperature towards β-H elimination. They selectively add to benzaldehyde in the presence of acetophenone but do not react with methyl iodide. The reaction of tertiary acyclic α-sulfonyl carbanions with ClTi(OiPr)3 in tetrahydrofuran (THF) gives different titanium derivatives with unspecified structures, which not only selectively react with benzaldehyde in the presence of acetophenone but are also alkylated by methyl iodide.
- Hess, Thomas,Raabe, Gerhard,Gais, Hans-Joachim
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p. 7134 - 7147
(2015/03/04)
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- Highly selective and efficient oxidation of sulfides with hydrogen peroxide catalyzed by a chromium substituted Keggin type polyoxometalate
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The catalytic oxidation of sulfides into the corresponding sulfones by a chromium substituted Keggin type polyoxometalate, (TBA)4[PW 11CrO39]·3H2O, was achieved using mild reaction conditions. Excellent yields were obtained using four equivalents of 30% H2O2. Under these reaction conditions, the sulfide group was highly reactive and other functional groups such as hydroxyl or a double bond were unaffected. Using a commercially available, eco-friendly, and cheap oxidant, mild reaction conditions, operational simplicity, practicality, short reaction times, high to excellent yields, and excellent chemoselectivity are some of the advantages of this catalytic system.
- Afrasiabi, Roozbeh,Farsani, Mostafa Riahi,Yadollahi, Bahram
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supporting information
p. 3923 - 3925
(2014/07/08)
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- Solvent free oxidation of sulfides to sulfones by H2O2 in the presence of chromium substituted polyoxometalate as catalyst
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Solvent-free oxidation of sulfides into sulfones by 30% hydrogen peroxide has been achieved using chromium substituted Keggin type polyoxometalate under mild reaction conditions in 94-100% yield. This catalytic system showed excellent activity in the oxidation of sulfide groups. The other active functional groups such as hydroxyl and C=C bond have been tolerated.
- Afrasiabi, Roozbeh,Jalilian, Fariba,Yadollahi, Bahram,Farsani, Mostafa Riahi
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p. 113 - 116
(2015/02/19)
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- A novel organic electron donor derived from N-methylisatin
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We report the reactivity of an electron donor derived from N-methylisatin on reduction by sodium amalgam. Transfer of a clear supernatant solution to iodoarenes affords the products of two-electron reduction. Reductions of sulfones, activated arenesulfonamides, and Weinreb amides are also reported.
- Sword, Ryan,O'Sullivan, Steven,Murphy, John A.
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p. 314 - 322
(2013/05/08)
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- Selectivity adjustment of SBA-15 based tungstate catalyst in oxidation of sulfides by incorporating a hydrophobic organic group inside the mesochannels
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A novel heterogeneous catalyst system comprising tungstate ions embedded into the hydrophobic mesochannels of SBA-15 was found to exhibit significant selectivity enhancement in oxidation of sulfides in water or water/CH 3CN using 30% H2O2. Our studies demonstrated that the presence of an n-octyl group in the interior of nanospaces of our catalyst system provides a hydrophobic/hydrophilic region in the mesochannels of the catalyst where the active tungstate species are located and in turn results in at least three distinct important features. First of all, the catalyst comprising the n-octyl group shows much better water tolerance than the catalysts not having hydrophobic organic moieties. Moreover, the nonproductive decomposition of H2O2 was significantly inhibited in the present catalyst system. The present catalyst system also offers an unprecedented selectivity changeover depending on the hydrophobic nature of the initial sulfides and/or the utilized solvent mixture. While high yields and excellent selectivities toward the corresponding sulfoxide were obtained in the oxidation of less hydrophobic sulfides in H2O as a reaction solvent, the selectivity pattern was shifted toward sulfones in the case of using more hydrophobic sulfides as substrates. On the other hand, in CH3CN/ H2O (1:1) as the reaction solvent, almost all of the studied sulfides were selectively oxidized to the corresponding sulfoxide in high yields. On the basis of several compelling observations, we have proposed a synergistic model to explain the origin of the observed selectivities. The catalyst was respectively recovered and reused in five and seven successive reaction runs in water and water/CH3CN, respectively, with only a slight decrease of reactivity.
- Karimi, Babak,Khorasani, Mojtaba
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p. 1657 - 1664
(2013/07/26)
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- Reductive cleavage of sulfones and sulfonamides by a neutral organic super-electron-donor (S.E.D.) reagent
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Sulfones and sulfonamides are reductively cleaved using the neutral and easily prepared organic electron-donor, bis-imidazolylidene 3. Copyright
- Schoenebeck, Franziska,Murphy, John A.,Zhou, Sheng-Ze,Uenoyama, Yoshitaka,Miclo, Yves,Tuttle, Tell
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p. 13368 - 13369
(2008/04/04)
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- Process for producing aryl alpha-haloalkyl sulfones
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A process for preparing alkenes by reaction of various sulfone substrates with carbon tetrahalide in the presence of a strong base. The reactions are accelerated by the presence of a polar compound. Sulfone carbanions attack the carbon tetrahalide to produce an α-halogenated intermediate and a dihalocarbene. α-Halosulfones having α' hydrogens are converted to alkenes in situ via the Ramberg-Backland reaction. Sulfones having α but no α' hydrogens are simply α-halogenated. The dihalocarbene generated in the reaction may attack the product, solvent, or another substrate to form other products. Alkenes produced by reaction of carbon tetrahalides with di-sec-alkyl sulfones are readily attacked by dihalocarbene to form the alkene-dihalocarbene adduct (a substituted 1,1-dihalocyclopropane).
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