3079-27-4Relevant academic research and scientific papers
Selective Oxidation of Sulfides to Sulfoxides by a Polymeric Reagent Electrochemically Generated and Recycled in Situ
Yoshida, Jun-ichi,Sofuku, Hiroshi,Kawabata, Nariyoshi
, p. 1243 - 1244 (1983)
A polymeric reagent electrochemically generated from crosslinked poly(4-vinylpyridine) hydrobromide was found to oxidize sulfides to give sulfoxides in high yields.The exhausted polymeric reagent was regenerated by continuous electrochemical oxidation in situ.
Persulfoxide and thiadioxirane intermediates in the reaction of sulfides and singlet oxygen
Watanabe, Yasumasa,Kuriki, Nobuo,Ishiguro, Katsuya,Sawaki, Yasuhiko
, p. 2677 - 2682 (1991)
Structure and reactivity of intermediates in the reaction of sulfides and singlet oxygen have been studied in aprotic solvents. It is shown that sulfoxides and sulfones are the major products at the initial stage of reaction. While the sulfoxide formation is more sensitive to the electronic of substituents, the steric retardation is more significant for sulfone formation. The effect of additives also revealed the sharp contrast between the two reactions; sulfoxide formation is accelerated significantly by protic or coordinating solvents, but sulfone formation is never affected by additives. 18O-tracer experiments indicated that the two oxygen in sulfones from one molecule. The activation energy for sulfone formation is positive in contrast to the sulfoxide case. These facts that thiadioxirane intermediates are surely formed via a nonpolar reaction in competition with persulfoxide formation. It is also shown that persulfoxides are stabilized by coordinating solvents as well as by protic ones. The stability of thiadioxiranes is discussed on the of theoretical calculations.
A Facile Synthesis of Sulfoxides by Oxidation of Sulfides with Sodium Bromite in an Aprotic Solvent in the Presence of Clay Minerals
Hirano, Masao,Kudo, Hiroyuki,Morimoto, Takashi
, p. 1744 - 1746 (1992)
The title oxidation has been performed in dichloromethane in the presence of "wet"-montmorillonite and -kaolin.The substrates studied include dialkyl, alkyl aryl, diaryl, and cyclic sulfides, which give the corresponding sulfoxides in good yields under ne
Lehualides e - K, cytotoxic metabolites from the tongan marine sponge plakortis sp.
Barber, Jacqueline M.,Quek, Natelle C. H.,Leahy, Dora C.,Miller, John H.,Bellows, David S.,Northcote, Peter T.
, p. 809 - 815 (2011)
Spectroscopy-guided chemical analysis of a marine sponge from the genus Plakortis, collected in Tonga, yielded seven new metabolites of polyketide origin, lehualides E-K (5-11), four of which incorporate various sulfur functionalities. The structures of compounds 5-11 were elucidated by interpretation of spectroscopic data and spectral comparison with model compounds. The biological activities of compounds 6-9 were investigated against human promyeloid leukemic HL-60 cells and two yeast strains, wild-type and a drug-sensitive mutant.
Selective Electroenzymatic Oxyfunctionalization by Alkane Monooxygenase in a Biofuel Cell
Abdellaoui, Sofiene,Chen, Hui,Kummer, Matthew J.,Malapit, Christian A.,Minteer, Shelley D.,You, Chun,Yuan, Mengwei
supporting information, p. 8969 - 8973 (2020/04/20)
Aliphatic synthetic intermediates with high added value are generally produced from alkane sources (e.g., petroleum) by inert carbon–hydrogen (C?H) bond activation using classical chemical methods (i.e. high temperature, rare metals). As an alternative approach for these reactions, alkane monooxygenase from Pseudomonas putida (alkB) is able to catalyze the difficult terminal oxyfunctionalization of alkanes selectively and under mild conditions. Herein, we report an electrosynthetic system using an alkB biocathode which produces alcohols, epoxides, and sulfoxides through bioelectrochemical hydroxylation, epoxidation, sulfoxidation, and demethylation. The capacity of the alkB binding pocket to protect internal functional groups is also demonstrated. By coupling our alkB biocathode with a hydrogenase bioanode and using H2 as a clean fuel source, we have developed and characterized a series of enzymatic fuel cells capable of oxyfunctionalization while simultaneously producing electricity.
Photoredox catalysis for oxygenation/deoxygenation between sulfides and sulfoxides by visible-light-responsive polyoxometalates
Suzuki, Kosuke,Jeong, Jinu,Yamaguchi, Kazuya,Mizuno, Noritaka
, p. 1014 - 1021 (2016/02/19)
In this paper, we report the unique visible-light-responsive photoredox catalysis of a divacant lacunary silicotungstate TBA4H4[γ-SiW10O36] (SiW10) for functional group transformations of sulfur-containing compounds; namely, (i) aerobic oxygenation of sulfides to sulfoxides and (ii) deoxygenation of sulfoxides to sulfides. In the presence of suitable additives, such as Ce3+ (electron transfer mediator for oxygenation) and an alcohol (electron and proton donor for deoxygenation), SiW10 shows visible-light-induced charge transfers by using the newly formed highest occupied molecular orbitals derived from the coordinating Ce3+ or alcohol at the vacant site of SiW10. Consequently, oxygenation of sulfides and deoxygenation of sulfoxides can selectively proceed by irradiation with visible light (λ > 400 nm) to afford the corresponding desired products in high yields. The SiW10 photocatalysts can readily be recovered and reused for these transformations. Based on evidence from several experiments, the roles of the additives as well as the reaction mechanisms for these transformations are also discussed.
Molybdenum-doped α-MnO2 as an efficient reusable heterogeneous catalyst for aerobic sulfide oxygenation
Uematsu, Tsubasa,Miyamoto, Yumi,Ogasawara, Yoshiyuki,Suzuki, Kosuke,Yamaguchi, Kazuya,Mizuno, Noritaka
, p. 222 - 233 (2015/12/31)
Oxygenation of sulfides to sulfoxides and/or sulfones is an important transformation, and the development of efficient heterogeneous catalysts for oxygenation, which can utilize O2 as the terminal oxidant, is highly desired. In this study, we have successfully developed manganese oxide-based efficient heterogeneous catalysts for aerobic oxygenation of sulfides. Firstly, we prepared four kinds of manganese oxides possessing different crystal structures, such as α-MnO2, β-MnO2, γ-MnO2, and δ-MnO2, and their structure-activity relationships were examined for the aerobic oxygenation of thioanisole. Amongst them, α-MnO2 showed the best catalytic performance for the oxygenation. Moreover, α-MnO2 was highly stable during the catalytic oxygenation possibly due to the tunnel K+ ions. In order to further improve the catalytic performance of α-MnO2, substitutional doping of transition metal cations, such as Mo6+, V5+, Cr3+, and Cu2+, into the framework was carried out. Undoped α-MnO2 possessed a fibrous morphology. When high-valent transition metal cations were doped, especially Mo6+, the lengths of the fibers drastically shortened to form grain-like aggregates of ultrafine nanocrystals, resulting in an increase in specific surface areas and the numbers of catalytically active surface sites. In the presence of Mo6+-doped α-MnO2 (Mo-MnO2), various kinds of sulfides could efficiently be oxidized to the corresponding sulfoxides as the major products. The observed catalysis was truly heterogeneous, and Mo-MnO2 could repeatedly be reused while keeping its high catalytic performance. Besides sulfide oxygenation, Mo-MnO2 could efficiently catalyze several aerobic oxidative functional group transformations through single-electron transfer oxidation processes, namely, oxygenation of alkylarenes, oxidative α-cyanation of trialkylamines, and oxidative S-cyanation of benzenethiols.
Polyoxomolybdate-Calix[4]arene Hybrid: A Catalyst for Sulfoxidation Reactions with Hydrogen Peroxide
Meninno, Sara,Parrella, Alessandro,Brancatelli, Giovanna,Geremia, Silvano,Gaeta, Carmine,Talotta, Carmen,Neri, Placido,Lattanzi, Alessandra
supporting information, p. 5100 - 5103 (2015/11/03)
An easily accessible polyoxomolybdate-calix[4]arene hybrid 1 has been synthesized and applied as a heterogeneous catalyst in the sulfoxidation of thioethers to sulfoxides and to sulfones under strictly stoichiometric amounts of 30% H2O2 in CH3CN as the solvent. This study represents the first promising example of successful employment of calixarenes-polyoxometalate (POM) hybrid materials in the area of catalytic oxidations.
Synthesis and oxidation catalysis of a Ti-substituted phosphotungstate, and identification of the active oxygen species
Takahashi, Eri,Kamata, Keigo,Kikukawa, Yuji,Sato, Sota,Suzuki, Kosuke,Yamaguchi, Kazuya,Mizuno, Noritaka
, p. 4778 - 4789 (2015/10/05)
In this paper, we report the synthesis of a Ti-substituted phosphotungstate, TBA6[(γ-PW10O36)2Ti4(μ-O)2(μ-OH)4] (I, TBA = tetra-n-butylammonium), and its application to H2O2-based oxidation. Firstly, an organic solvent-soluble dilacunary phosphotungstate precursor, TBA3[γ-PW10O34(H2O)2] (PW10), has been synthesized. By the reaction of PW10 and TiO(acac)2 (acac = acetylacetonate) in an organic medium (acetonitrile), I can be obtained. Compound I possesses a tetranuclear Ti core which can effectively activate H2O2 and shows high catalytic performance for several oxidation reactions, such as epoxidation of alkenes, oxygenation of sulfides, oxidative bromination of unsaturated compounds, and hydroxylation of anisole, giving the corresponding oxidation products with high efficiencies and selectivities. The catalytic performance of I is much superior to those of previously reported Ti-substituted polyoxometalates. In addition, I is highly durable during catalysis and can be reused several times while keeping its high catalytic performance. Furthermore, we have successfully isolated the truly catalytically active species for the present I-catalyzed oxidation, TBA6[(γ-PW10O36)2Ti4(μ-η2:η2-O2)4] (II), and its anion structure has been determined by X-ray crystallographic analysis. All of the four Ti2-μ-η2:η2-peroxo species in II are active for stoichiometric oxidation (without H2O2), and II is included in the catalytic cycle for I-catalyzed oxidation.
Selective Oxidation with Aqueous Hydrogen Peroxide by [PO4{WO(O2)2}4]3- Supported on Zinc-Modified Tin Dioxide
Nojima, Susumu,Kamata, Keigo,Suzuki, Kosuke,Yamaguchi, Kazuya,Mizuno, Noritaka
, p. 1097 - 1104 (2015/04/14)
We prepared supported phosphorus-containing tetranuclear peroxotungstate ([PO4{WO(O2)2}4]3-, denoted by PW4) catalysts by using zinc-modified SnO2 supports with different zinc contents [PW4-Zn(x)/SnO2, in which x denotes the zinc content (wt%)]. The supported catalysts, in particular PW4-Zn(0.8)/SnO2, could act as efficient and reusable heterogeneous catalysts for selective oxidation with aqueous H2O2 as the terminal oxidant. The catalytic performance of PW4-Zn(0.8)/SnO2 was much superior to those of the corresponding homogeneous analogue THA3PW4 (THA=tetra-n-hexylammonium) and the previously reported tungstate-based heterogeneous catalysts such as our W-Zn/SnO2. In the presence of PW4-Zn(0.8)/SnO2, various types of organic substrates such as alkenes, amines, silanes, and sulfides could be converted into the corresponding oxygenated products in high to excellent yields by using near-stoichiometric amounts of H2O2 with respect to the substrates (typically 1.2 equiv.). The PW4 species interacting with highly dispersed Zn2+ species on SnO2 likely plays an important role in the present oxidation.
