Diphenyl Sulfoxides Research Articles

Suzuki–Miyaura Cross-Coupling of Sulfoxides

The utilization of diphenyl sulfoxides as versatile electrophilic coupling partners for the Suzuki–Miyaura reaction via C–S bond cleavage was successfully developed under palladium-N-heterocyclic carbene catalysis. The reactions showed good functional group compatibility, proceeded well under mild conditions, and provided biaryls in yields of up to 96%. A wide range of useful functional groups, such as fluoro, chloro, ether, hydroxyl, amide, cyano, keto, trimethylsilyl (TMS), and ester were tolerated under the reaction conditions; however, the use of phenylboronic anhydride and arylboronic acid pinacol esters generally would lead low yields. Good regioselectivity for the electron-poor phenyl group was achieved when unsymmetrical diphenyl sulfoxides were used. The protocol is applicable at the gram scale even with half the amount of catalyst. Density functional theory calculations were performed to investigate the reaction mechanism, indicating that the reaction occurred through oxidative addition, transmetalation, and reductive elimination to provide the final coupling product.

Molecular polarizability of organic compounds and their complexes: LIX. Molar volumes, intrinsic atomic solvation radii, and spatial structures of certain conformationally flexible compounds in solutions

The molar volumes and structures in individual liquids and solutions of a series of conformationally flexible compounds, such as alkanes and diaryl-substituted systems with sp3-hybridized bridging atoms, were analyzed in terms of intrinsic solvation radii of atoms constituting the molecule. Intrinsic solvation atomic radii were determined for various molecules to show that they are larger than the van der Waals radii of the same atoms. An approach to parametrization of the intrinsic solvation radii of atoms constituting a molecule, using appropriate model compounds, was proposed. From the resulting values of intrinsic atomic solvation radii, the possible conformations of a series of diphenylmethanes, diphenylsilanes, diphenyl sulfides, diphenyl sulfoxides, and diphenyl sulfones in solutions were assessed.

Kinetics and mechanism of oxidation of dimethyl and diphenyl sulfoxides by tetrabutylammonium tribromide

The kinetics of oxidative conversion of dimethyl and diphenyl sulfoxides to corresponding sulfones with environmentally benign tetrabutylammonium tribromide was investigated in 50% v/v aqueous acetic acid medium. The reactions were carried out under pseudo first-order conditions keeping an excess of sulfoxides over that of the oxidant. The tribromide ion, , was found to be the active species of the oxidant. The electrophilic attack of the ion on the nucleophilic sulfur of the sulfoxide leads to the formation of a complex between the reactants in a prior equilibrium. The complex formed undergoes rate-determining hydrolysis to yield sulfone as the product. The complex formation was kinetically verified by the Michealis—Menten plot. The formation constants for the complexes and the rate constant for the slow hydrolysis step were determined by studying the reaction at four different temperatures. The values of observed rate constant and the complex formation constant for dimethyl sulfoxide were found to be comparatively greater than that of diphenyl sulfoxide due to the positive inductive effect of methyl groups. The thermodynamic parameters with respect to the slow step of the reaction were determined and the values support the proposed mechanism.

ChemInform Abstract: Diphenyl Sulfoxides as Selective Antagonists of the Muscarinic M2 Receptor.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Diphenyl sulfoxides as selective antagonists of the muscarinic M 2 receptor

Structure–activity studies on [4-(phenylsulfonyl)phenyl]methylpiperazine led to the discovery of 4-cyclohexyl-α-[4-[[4-methoxyphenyl]( S)-sulfinyl]phenyl]-1-piperazineacetonitrile, 1, an M 2 selective muscarinic antagonist. Affinity at the cloned human M 2 receptor was 2.7 nM; the M 1/M 2 selectivity is 40-fold.

Sulfoxide-containing aromatic nitrogen mustards as hypoxia-directed bioreductive cytotoxins.

A series of diaryl and alkylaryl sulfoxide-containing nitrogen mustards were synthesized and evaluated for their hypoxia-selective cytotoxicity against V-79 cells in vitro as well as for their metabolism profiles with the rat S-9 fractions. In general, the diaryl sulfoxides (4, 5, and 7-9) showed much greater hypoxia selectivity (11-27-fold) than the alkylaryl sulfoxides (approximately 3-fold) (1 and 3). The fused diphenyl sulfoxides (10 and 11), on the other hand, showed very low hypoxia selectivity (1.3-3-fold). Compound 10 was highly cytotoxic under both aerobic and anaerobic conditions, while 11 showed low cytotoxicity under both conditions. The bioreduction of 8 by the rat S-9 fraction under anaerobic conditions was inhibited by menadione and enhanced by benzaldehyde, acetaldehyde, or 2-hydroxypyrimidine suggesting the involvement of aldehyde oxidase in the reduction of the sulfoxides. Bioreductive metabolism studies of selected model sulfoxides suggested that diaryl sulfoxides are better substrates for aldehyde oxidase than alkylaryl sulfoxides.

ChemInform Abstract: Structure‐Based Design of Substituted Diphenyl Sulfones and Sulfoxides as Lipophilic Inhibitors of Thymidylate Synthase.

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Structure-based design of substituted diphenyl sulfones and sulfoxides as lipophilic inhibitors of thymidylate synthase.

Six new diphenyl sulfoxide and five new diphenyl sulfones were designed, synthesized, and tested for their inhibition of human and Escherichia coli thymidylate synthase (TS) and of the growth of cells in tissue culture. The best sulfoxide inhibitor of human TS was 3-chloro-N-((3,4-dihydro-2-methyl-4-oxo-6-quinazolinyl)methyl)-4- (phenylsulfinyl)-N-(prop-2-ynyl)-aniline (7c) that had a Ki of 27 nM. No sulfone improved on TS inhibition by the previously reported 4-(N-((3,4-dihydro-2-methyl-6-quinazolinyl)methyl)-N-prop-2- ynylamino)phenyl phenyl sulfone (Ki = 12 nM). Nevertheless, one sulfone, 4-((2-chlorophenyl)sulfonyl)-N-((3,4-dihydro-2-methyl-4-oxo-6- quinazolinyl)methyl)-N-(prop-2-ynyl)aniline, was selected, on the basis of its inhibition of both TS and cell growth, for antitumor testing; it gave a 61% increase in life span to mice bearing the thymidino kinase-deficient L5178Y (TK-) lymphoma. A crystal structure of N-((3,4-dihydro-2-methyl-4-oxo-6-quinazolinyl)methyl)-4-((2- methylphenyl)sulfinyl)-N-(prop-2-ynyl)aniline complexed with E. coli TS was solved and revealed selective binding of one sulfoxide enantiomer. AMBER calculations showed that the enantioselection was due to asymmetric electrostatic effects at the mouth of the active site. In contrast, a similar crystal structure of the sulfoxide 7c, along with AMBER calculations, indicated that both enantiomers bound, but with different affinities. The side chain of Phe176 shifted in order to structurally accommodate the chlorine of the more weakly bound enantiomer.

Aqueous High-Temperature Chemistry of Carbo- and Heterocycles. 28.1 Reactions of Aryl Sulfoxides and Sulfones in Sub- and Supercritical Water at 200−460 °C

Diphenyl and methyl phenyl sulfones and sulfoxides and dibenzothiophene sulfone were treated at 460 °C with water, 15% aqueous formic acid, and 15% aqueous sodium formate. Thermal comparisons were ...

ChemInform Abstract: 4,4′‐Dichloro‐ and 4‐Chloro‐4′‐hydroxy‐2,2′‐bis(trifluoromethyl) diphenyl Sulfoxides and Sulfones.

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O-versusS-protonation in diaryl sulfoxides: A semi-empirical mo investigation: Comparison with solution studies in superacids

The protonation of diphenyl sulfoxide and several substituted diphenyl sulfoxides was probed by the MNDO-PM3 method to gain a theoretical insight into the experimentally observed preference for stable diphenyl sulfoxonium ion formation (O-protonation) in 1:1 FSO3H—SbF5 (Magic Acid)—SO2. In agreement with solution studies, O- protonation is uniformly favored (by ca 17 kcal mol −1) over S-protonation. The differences in the heats of formation of protonated and unprotonated diphenyl sulfoxides are increased by electron-withdrawing substituents (F, CF3) and decreased by electron-donating groups (Me, OMe). Variations in the SO bond length and bond order in the onium ions are compatible with simple resonance arguments and the oxonium/sulfonium character of both the O- and S-protonated onium ions. Surprisingly, the O- and S-protonated dibenzothiophene S-oxides are predicted to have identical energetics as compared with the corresponding protonated diphenyl sulfoxides. On structure optimization dibenzothiophene S-oxide itself, if the initial geometry is somewhat twisted, rearranges by ring expansion to give a new heterocycle with lower energy. A rotational barrier study on the parent O-protonated diphenyl sulfoxide showed two minima, separated by 1.3 kcal mol−1, at HOSC dihedral angles of 60° and 240°. The two conformations correspond to syn and anti orientations of the OH proton relative to the aromatic rings, and support the lowtemperature solution observations of the presence of two distinct sulfoxonium ions in solution. The rotational barriers for diphenyl sulfoxonium cation are compared with those of O-protonated dimethyl sulfoxide.

Reduction of Sulfoxides with Sodium or Benzyl Bromide

The reduction of dimethyl and diphenyl sulfoxides, and of alkyl and arylbenzyl sulfoxides to the corresponding sulfides can be carried out using sodium bromide without solvent or benzyl bromide in dimethylformamide, mostly through an oxidation-reduction cycle catalyzed by developing hydrobromic acid.

Vinylpolymerisation mit reduzierenden Übergangsmetallverbindungen. VII. Polymerisation von Methylmethacrylat in Gegenwart von Molybdän(III)‐chlorid‐Sulfoxid‐Systemen

Vinyl Polymerization Initiated by Reducing Compounds of Transition Metals. VII. Polymerization of Methyl Methacrylate in the Presence of Molybdenum(III) Chloride/Sulfoxide SystemsThe polymerization of methyl methacrylate initiated by the molybdenum(III) chloride/dimethyl sulfoxide redox system was carried out at 70° in 1, 4‐dioxane. The rate of polymerization can be described by the equation Rp = k · [MoCl3]0,5 · [DMSO]0,5 · [MMA]1,0. The overall activation energy was estimated to be 36.0 kJ/mol. It was found that diethyl, dipropyl, dibutyl, diphenyl and dibenzyl sulfoxides could also initiate the polymerization of methyl methacrylate in the presence of molybdenum(III) chloride, whereas vanadium(II) chloride, vanadium(III) chloride, titanium(III) chloride and chromium(II) acetate are inactive in combination with sulfoxides.

Kinetics of the peroxydisulfate oxidation of sulfoxides in buffered solution. 2. The effect of initial sulfoxide concentration with diethyl and diphenyl sulfoxides

Kinetics of the peroxydisulfate oxidation of sulfoxides in buffered solution. 2. The effect of initial sulfoxide concentration with diethyl and diphenyl sulfoxides

ChemInform Abstract: RELAXATION PROCESSES OF SOME AROMATIC SULFIDES, SULFOXIDES, AND SULFONES IN A POLYSTYRENE MATRIX

Dielectric absorption studies have been made of a number of aromatic sulfides, sulfoxides, and sulfones in a polystyrene matrix at a variety of temperatures in the frequency range of 102–105 Hz, and in three cases between 104–107 Hz. One compound, bis (4‐pyridyl) sulfide, was also examined as a pure compressed solid in the frequency range of 104–107 Hz. The Eyring parameters have been determined and used to characterize the relaxation processes. Low enthalpies of activation (∼15 kJ mol−1) have been estimated for an intramolecular relaxation process of diphenyl, bis (4‐tolyl) and bis (4‐pyridyl) sulfide, and rotation about the C–S bond in these symmetrical aromatic sulfides would, thus, be expected to occur quite readily. These low barriers are to be contrasted with those for the molecular relaxation values of 60–78 kJ mol−1 for diphenyl, bis(4‐tolyl) and bis(4‐chlorophenyl) sulfoxides and sulfones. The enthalpies of activation (∼39 kJ mol−1) for the molecular relaxation of the disklike molecules, dibenzothiophene and its oxides, are also lower than those for the corresponding nonplanar diphenyl sulfur oxides.

Reaction of benzene with diphenyl sulfoxides.

Reaction of benzene with diphenyl sulfoxides.

Relaxation processes of some aromatic sulfides, sulfoxides, and sulfones in a polystyrene matrix

Dielectric absorption studies have been made of a number of aromatic sulfides, sulfoxides, and sulfones in a polystyrene matrix at a variety of temperatures in the frequency range of 102–105 Hz, and in three cases between 104–107 Hz. One compound, bis (4-pyridyl) sulfide, was also examined as a pure compressed solid in the frequency range of 104–107 Hz. The Eyring parameters have been determined and used to characterize the relaxation processes. Low enthalpies of activation (∼15 kJ mol−1) have been estimated for an intramolecular relaxation process of diphenyl, bis (4-tolyl) and bis (4-pyridyl) sulfide, and rotation about the C–S bond in these symmetrical aromatic sulfides would, thus, be expected to occur quite readily. These low barriers are to be contrasted with those for the molecular relaxation values of 60–78 kJ mol−1 for diphenyl, bis(4-tolyl) and bis(4-chlorophenyl) sulfoxides and sulfones. The enthalpies of activation (∼39 kJ mol−1) for the molecular relaxation of the disklike molecules, dibenzothiophene and its oxides, are also lower than those for the corresponding nonplanar diphenyl sulfur oxides.

ChemInform Abstract: CONFORMATIONS OF BRIDGED DIPHENYLS PART 5, A NUCLEAR MAGNETIC RESONANCE COMPARATIVE STUDY OF THE CONFORMATIONS OF IDENTICALLY SUBSTITUTED DIPHENYL ETHERS, SULFIDES, METHANES, KETONES, SULFOXIDES, AND SULFONES

Chemischer InformationsdienstVolume 5, Issue 18 Physical Organic Chemistry ChemInform Abstract: CONFORMATIONS OF BRIDGED DIPHENYLS PART 5, A NUCLEAR MAGNETIC RESONANCE COMPARATIVE STUDY OF THE CONFORMATIONS OF IDENTICALLY SUBSTITUTED DIPHENYL ETHERS, SULFIDES, METHANES, KETONES, SULFOXIDES, AND SULFONES HARM BENJAMINS, HARM BENJAMINSSearch for more papers by this authorW. DAVID CHANDLER, W. DAVID CHANDLERSearch for more papers by this author HARM BENJAMINS, HARM BENJAMINSSearch for more papers by this authorW. DAVID CHANDLER, W. DAVID CHANDLERSearch for more papers by this author First published: May 7, 1974 https://doi.org/10.1002/chin.197418077AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume5, Issue18May 7, 1974 RelatedInformation

Conformations of Bridged Diphenyls. V. A Nuclear Magnetic Resonance Comparative Study of the Conformations of Identically Substituted Diphenyl Ethers, Sulfides, Methanes, Ketones, Sulfoxides, and Sulfones

Using n.m.r. methods developed in earlier papers, the conformations of two series, one doubly ortho-substituted and one triply ortho-substituted, of six identically substituted bridged diphenyls were compared. The ethers, sulfides, and methanes have been shown to adopt the same conformation in which the di-ortho-substituted ring is perpendicular to the central bridge plane while the other ring lies in that plane and an ortho hydrogen takes up the "inside" or "proximal" position. The benzophenones and sulfoxides prefer a conformation in which the dihedral angle between each ring and the central plane is about 40–50° and an ortho hydrogen adopts the "outside" or "distal" position. The sulfones adopt a conformation in which the two rings are more nearly perpendicular to the central plane.

REACTIONS OF COPPER-CARBENOIDS WITH SULFOXIDES

Abstract The copper chelate-catalyzed reaction of α-diazoacetophenones with substituted diphenyl sulfoxides gave two types of products, diaryl sulfides (V) and oxosulfonium ylides (VI), of which ratios depended on the substituents of α-diazoacetophenones and of diaryl sulfoxides. The oxosulfonium ylides exhibit a novel reaction with phenylglyoxal affording oxosulfonium glyoxalylphenacylides (VII) in the presence of copper acetylacetonate. When copper-phthalocyanine was employed as a catalyst, the reaction gave a lactone (X) besides (V).