34009-06-8Relevant academic research and scientific papers
One-pot synthesis of aryl sulfones from organometallic reagents and iodonium salts
Margraf, Natalie,Manolikakes, Georg
, p. 2582 - 2600 (2015/03/18)
A transition-metal-free arylation of lithium, magnesium, and zinc sulfinates with diaryliodonium salts is described. The sulfinic acid salts were prepared from the reaction of the corresponding organometallic reagents and sulfur dioxide. Combination of the three single steps (preparation of the organometallic compound, sulfinate formation, and arylation) leads to a one-pot sequence for the synthesis of aryl sulfones from simple starting materials. The chemoselectivity of unsymmetrical diaryliodonium salts has been investigated. Potential and limitations of this method will be discussed.
Selectivity adjustment of SBA-15 based tungstate catalyst in oxidation of sulfides by incorporating a hydrophobic organic group inside the mesochannels
Karimi, Babak,Khorasani, Mojtaba
, p. 1657 - 1664 (2013/07/26)
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.
Arylation of lithium sulfinates with diaryliodonium salts: A direct and versatile access to arylsulfones
Umierski, Natalie,Manolikakes, Georg
supporting information, p. 4972 - 4975 (2013/10/22)
An efficient, transition-metal-free arylation of lithium sulfinates, which are readily accessible from reactions of organolithium reagents with sulfur dioxide, is described. Based on this method, a practical protocol for the direct transformation of (hetero)arenes and (hetero)aromatic halides into diarylsulfones was developed.
Highly atom-economic, catalyst- and solvent-free oxidation of sulfides into sulfones using 30% aqueous H2O2
Jereb, Marjan
supporting information, p. 3047 - 3052,6 (2020/09/16)
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.
Experimental and theoretical investigation of the enantiomerization of Lithium α-tert-butylsulfonyl carbanion salts and the determination of their structures in solution and in the crystal
Scholz, Roland,Hellmann, Gunther,Rohs, Susanne,Raabe, Gerhard,Runsink, Jan,Oezdemir, Diana,Luche, Olaf,Hess, Thomas,Giesen, Alexander W.,Atodiresei, Juliana,Lindner, Hans J.,Gais, Hans-Joachim
supporting information; experimental part, p. 4559 - 4587 (2010/10/19)
Dynamic NMR (DNMR) spectroscopy of [R1C(R2)SO 2R3]Li (R1, R2 = alkyl, phenyl; R3 = Ph, tBu, adamantyl, CEt3) in [D8]THF has shown that the S-tBu, S-adamantyl, and S-CEt3 derivatives have a significantly higher enantiomerization barrier than their S-Ph analogues. C α-S bond rotation is most likely the rate-determining step of the enantiomerization of the salts bearing a bulky group at the S atom and two substituents at the Cα atom. Ab initio calculations on [Me(Ph)- SO 2tBu]- gave information about the two Cα-S rotational barriers, which are dominated by steric effects. Cryoscopy of [R1C(R 2)SO2tBu]Li in THF at -108°C revealed the existence of monomers and dimers. X-ray crystal structure analysis of the monomers and dimers of [R1C(R2)SO2tBu]Li·L n (R1 = Me, Et, tBuCH2, PhCH2, tBu; R2 = Ph, L = THF, 12-crown-4, PMDTA) and [R1C(R 2)SO2Ph]Li·2diglyme [R1 = R2 = Me, Et; R1-R2 = (CH2)5] showed them to be O-Li contact ion pairs (CIPs). The monomers and dimers have a Cα-S conformation in which the lone-pair orbital at the Cα atom bisects the O-S-O angle and a significantly shortened Cα-S bond. The Cα atom of [R1C(R2)SO2R 3]Li·Ln (R1 = Ph; R3 = Ph, tBu) is planar, whereas the Cα atom of [R1C(R 2)SO2R3]Li·Ln (R1 = R2 = alkyl) is strongly pyramidalized in the case of R3 = Ph and most likely planar for R3 = tBu. Ab initio calculations on [MeC- (Me)SO2R]- gave a pyramidalized Cα atom for R = Me and a nearly planar one for R = CF3 and tBu. The [R1C(R 2)SO2-tBu]Li salts were characterized by 1H, 13C, and 6Li NMR spectroscopy. 1H{ 1H} and 6Li{1H} NOE experiments are in accordance with the existence of O-Li CIPs. 1H and 13C NMR spectroscopy of [R1C(R2)SO2tBu]Li in [D 8]THF at low temperatures showed equilibrium mixtures of up to five different species being most likely monomeric and dimeric O-Li CIPs with different configurations. According to 7Li NMR spectroscopy, the addition of HMPA to [MeC(Ph)SO2tBu]Li in [D8]THF at low temperatures causes the formation of the separated ion pair [MeC(Ph)SO 2tBu]Li(HMPA)4.
Experimental verification of diverging mechanisms in the binding of ether, thioether, and sulfone ligands to a dirhodium tetracarboxylate
Mattiza, Jens T.,Meyer, Vera J.,Duddeck, Helmut
experimental part, p. 192 - 197 (2010/07/05)
Complexation of the oxygen atom in 2-butylphenylethers and sulfur in 2-butylphenylthioethers to a rhodium atom in dirhodium tetracarboxylate Rh (II)2[(R)-(+)-MTPA]4 is compared. Oxygen atoms complex via electrostatic attra
1,2-Bis(phenylsulfonyl)-1H-indole as an acceptor of organocuprate nucleophiles
Qian, David C.,Alford, Philip E.,Kishbaugh, Tara L. S.,Jones, Sean T.,Gribble, Gordon W.
, p. 66 - 73 (2012/11/07)
1,2-Bis(phenylsulfonyl)-1H-indole is a novel example of an electron-deficient indole that undergoes nucleophilic attack at C-3. Though a variety of other organometallic nucleophiles fail to engender nucleophilic substitution, organocuprates produce 3-substituted 2-(phenylsulfonyl)-1H- indoles. These reactions contribute to the growing number of examples of nucleophilic addition to the indole core. ARKAT USA, Inc.
Template Effects of a Clay-Chelate Adduct on the Asymmetric Oxidation of Alkyl Phenyl Sulphide by Sodium Metaperiodate
Yamagishi, Akihiko
, p. 290 - 291 (2007/10/02)
Cyclohexyl phenyl sulphide adsorbed by Δ-tris(1,10-phenanthroline)nickel(II)-montmorillonite was oxidized by sodium metaperiodate at 25 deg C in water to give (S)-cyclohexyl phenyl sulphoxide with an optical purity of 78percent.
Electrochemical oxidation of carboxylic acid anions in the presence of some mono- and di-subsituted olefins
Champagne, Philippe J.,Renaud, Roger N.
, p. 1101 - 1105 (2007/10/02)
The anodic oxidation of the sodium salts of acetic, propionic, and isovaleric acids was performed in the presence of a series of ethylenic compounds bearing electron-withdrawing substituents.The results showed that under certain experimental conditions the electrogenerated radicals added to the ethylenic double bond to give mainly 1,2-dialkylated products.The stereoisomers obtained were separated and whenever possible, identified.Their physical properties are reported.
Stereochemistry of Free-Radical Eliminations on β-Phenylsulfonyl Radicals
Boothe, Thomas E.,Greene, Joseph L.,Shevlin, Philip B.
, p. 794 - 797 (2007/10/02)
Tributyltin radicals have been allowed to react with erythro- and threo-2-bromo-3-(phenylsulfonyl)butane (5a,b) to generate β-(phenylsulfonyl)-sec-butyl radicals 9.The intermediate 9 eliminates phenylsulfonyl radicals to form 2-butenes in a nonstereospecific manner.The lack of stereospecificity is due to rotation about the C2-C3 bond before the loss of the phenylsulfonyl radical can occur and implies that the stabilization of the radical by sulfur bridging is negligible.
