- α-Diazo Sulfonium Triflates: Synthesis, Structure, and Application to the Synthesis of 1-(Dialkylamino)-1,2,3-triazoles
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The one-pot synthesis of a series of sulfonium salts containing transferable diazomethyl groups is described, and the structure of these compounds is elucidated by X-ray crystallography. Under photochemical conditions, reaction of these salts with N,N-dialkyl hydrazones affords 1-(dialkylamino)-1,2,3-triazoles via diazomethyl radical addition to the azomethine carbon followed by intramolecular ring closure. The straightforward transformation of the structures thus obtained into mesoionic carbene–metal complexes is also reported and the donor properties of these new ligands characterized.
- Li, Xiangdong,Golz, Christopher,Alcarazo, Manuel
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supporting information
p. 6943 - 6948
(2021/02/26)
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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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- Electrochemical oxidations of thioethers: Modulation of oxidation potential using a hydrogen bonding network
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A highly efficient chemo-selective electrochemical oxidation of thioethers to sulfoxides and sulfones was developed. The hydrogen bonding network generated from hexafluoro-2-propanol (HFIP) and acetic acid (AcOH) plays an important role in the modulation of oxidation potential. The hydrogen bonding network complexes strongly with the sulfoxide, making it less prone to further oxidation. Therefore, thioethers can be selectively electrochemically oxidized to sulfoxides and over-oxidization could be minimized. Moreover, this modulation of oxidization via hydrogen bonding was supported by density functional theory (DFT) calculations and cyclic voltammetry experiments.
- Liu, Shiwen,Chen, Bocheng,Yang, Yi,Yang, Yuhao,Chen, Qianjin,Zeng, Xiaojun,Xu, Bo
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- Applications of iron and nickel immobilized on hydroxyapatite-core-shell γ-Fe2O3 as a nanomagnetic catalyst for the chemoselective oxidation of sulfides to sulfoxides under solvent-free conditions
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In the present study, Fe2+ and Ni2+ immobilized on hydroxyapatite-core-shell γ-Fe2O3 (γ-Fe2O3@HAp-Fe2+ and γ-Fe2O3@HAp-Ni2+) with a high surface area has been synthesized and characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), and scanning electron microscope (SEM) techniques. Then, γ-Fe2O3@HAp-Fe2+ and γ-Fe2O3@HAp-Ni2+ were used as a new and magnetically recoverable nano catalyst for the selective oxidation of sulfides to sulfoxides with 33% aqueous H2O2 (0.5 mL) as an oxidant at room temperature in good to excellent yields and short reaction time. Nontoxicity of reagent, mild reaction condition, inexpensive and high catalytic activity, simple experimental procedure, short period of conversion and excellent yields, and ease of recovery from the reaction mixture using an external magnet are the advantages of the present method.
- Sajjadifar, Sami,Rezayati, Sobhan,Arzehgar, Zeinab,Abbaspour, Sima,Torabi Jafroudi, Mogharab
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p. 960 - 969
(2018/03/29)
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- Salt and photoresist composition containing the same
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A salt represented by the formula (X): wherein Q1 and Q2 each independently represent a fluorine atom etc., L1 and L2 independently each represent a C1-C17 divalent saturated hydrocarbon group, ring W1 represents a C3-C36 saturated hydrocarbon ring, R2 is independently in each occurrence a hydroxyl group etc., s represents an integer of 0 to 2, Z+ represents an organic counter ion, and W10 represents a group represented by the formula (X-1): wherein ring W2 represents a C4-C36 saturated hydrocarbon ring in which one or more —CH2— can be replaced by —O— or —CO—, with the proviso that at least one —CH2— in the C4-C36 saturated hydrocarbon ring is replaced by —CO—, R3 is independently in each occurrence a C1-C6 alkyl group etc., and t represents an integer of 0 to 2, or a group represented by the formula (X-2): wherein ring W3 represents a C3-C36 saturated hydrocarbon ring, R4 is independently in each occurrence a hydroxyl group etc., R5 is independently in each occurrence a C1-C6 alkyl group etc., v represents an integer of 1 to 3, and w represents an integer of 0 to 2.
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Page/Page column 170-172
(2016/06/20)
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- Selective sulfoxidation of thioethers and thioaryl boranes with nitrate, promoted by a molybdenum-copper catalytic system
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The catalytic reduction of nitrate by molybdo-enzymes plays a central role in the global biological cycle of nitrogen. However, the use of nitrates as oxidants in synthetic organic chemistry is very limited and typically requires very strong acidic and other extreme reaction conditions. We have developed a highly chemoselective and efficient catalytic process for the sulfoxidation of thioethers and arylthioethers containing boronic acid or boronic ester functional groups, using nitrate salts as oxidants. This homogeneous catalytic reaction was carried out in acetonitrile, where the MoO2Cl 2(OPPh3)2 complex 1 or a mixture of complex 1 with Cu(NO3)2 were used as catalysts. We examined the reaction mechanism using 1H, 15N, and 31P NMR techniques and 18O-labeled sodium nitrate (NaN18O 3) and show that the thioethers are oxidized by nitrate, generating nitrite. Our work adds to the existing chemical transformations available for organoboron compounds, providing straightforward accessibility to a variety of new substrates that could be suitable for Suzuki cross-coupling chemistry.
- Marom, Hanit,Antonov, Svetlana,Popowski, Yanay,Gozin, Michael
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experimental part
p. 5240 - 5246
(2011/08/09)
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- Oxidation of organic compounds by sulfonated porous carbon and hydrogen peroxide
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The oxidation of organic compounds by sulfonated porous carbon and H 2O2 was studied at room temperature. Alkyl and aryl sulfides were oxidized to the corresponding sulfoxides or sulfones in excellent yields. Secondary alcohols were also converted to the corresponding esters/lactones and aldehydes to methyl esters in good yields. Moreover, aliphatic tertiary amines and substituted pyridines were oxidized to N-oxides.
- Shokrolahi, Arash,Zali, Abbas,Keshavarz, Mohammad Hossein
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experimental part
p. 1427 - 1432
(2012/04/18)
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- Oxygenation reactions of various tricyclic fused aromatic compounds using Escherichia coli and Streptomyces lividans transformants carrying several arene dioxygenase genes.
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Bioconversion (biotransformation) experiments on arenes (aromatic compounds), including various tricyclic fused aromatic compounds such as fluorene, dibenzofuran, dibenzothiophene, carbazole, acridene, and phenanthridine, were done using the cells of Escherichia coli transformants expressing several arene dioxygenase genes. E. coli carrying the phenanthrene dioxygenase (phdABCD) genes derived from the marine bacterium Nocardioides sp. strain KP7 converted all of these tricyclic aromatic compounds, while E. coli carrying the Pseudomonas putida F1 toluene dioxygenase (todC1C2BA) genes or the P. pseudoalcaligenes KF707 biphenyl dioxygenase (bphA1A2A3A4) genes was not able to convert these substrates. Surprisingly, E. coli carrying hybrid dioxygenase (todC1::bphA2A3A4) genes with a subunit substitution between the toluene and biphenyl dioxygenases was able to convert fluorene, dibenzofuran, and dibenzothiophene. The cells of a Streptomyces lividans transformant carrying the phenanthrene dioxygenase genes were also evaluated for bioconversion of various tricyclic fused aromatic compounds. The ability of this actinomycete in their conversion was similar to that of E. coli carrying the corresponding genes. Products converted from the aromatic compounds with these recombinant bacterial cells were purified by column chromatography on silica gel, and identified by their MS and 1H and 13C NMR analyses. Several products, e.g., 4-hydroxyfluorene converted from fluorene, and cis-1,2-dihydroxy-1,2-dihydrophenanthridine, cis-9,10-dihydroxy-9,10-dihydrophenanthridine, and 10-hydroxyphenanthridine, which were converted from phenanthridine, were novel compounds.
- Shindo,Ohnishi,Chun,Takahashi,Hayashi,Saito,Iguchi,Furukawa,Harayama,Horinouchi,Misawa
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p. 2472 - 2481
(2007/10/03)
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- Sulfuryl chloride in the synthesis of derivatives of dibenzothiophene, phenoxathiin, and thianthrene
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Reactions of sulfuryl chloride with dibenzothiophene and related heterocyclic systems have been studied. It is shown that under different conditions, C- or S-halogenation of the heterocycle takes place. A series of new chlorine derivatives of dibenzothiophene, phenoxathiin and thianthrene have been synthesized and characterized. 1997 Plenum Publishing Corporation.
- Savin,Nedel'kin,Zverev
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p. 333 - 337
(2007/10/03)
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- Catalytic oxidation of chlorpromazine and related phenothiazines. Cation radicalsas the reactive intermediates in sulfoxide formation
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The aerial oxidation of various phenothiazines to the corresponding sulfoxides is catalysed by nitric oxide and related nitrogen oxides.The reactive intermediate in the catalytic autooxidation is the phenothiazine cation radical which is subsequently tran
- Bosch, Eric,Kochi, Jay K.
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p. 1057 - 1064
(2007/10/02)
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- Selective Catalysis of Thioether Oxidations with Dioxygen. Critical Role of Nitrosonium EDA Complexes in the Thermal and Photochemical Transfer of Oxygen Atom from Nitrogen Oxides to Sulfur Centers
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Various alkyl and aryl thioethers (R2S) are readily converted in high yields to sulfoxides in the presence of dioxygen and catalytic amounts of nitrogen dioxide.Separate experiments with stoichiometric amounts of reagents (under anaerobic conditions) esta
- Bosch, Eric,Kochi, Jay K.
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p. 3172 - 3183
(2007/10/02)
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- Benzoxathiete and related structures: experimental and quantum chemical studies
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The products, plausible intermediates, and their mechanisms of formation in the aprotic diazotization of 2-anilines with isoamyl nitrate have been investigated by experimental and quantum chemical methods.Oxidation of 1,2,3-benzthiadiazole with hydrogen peroxide in acetic acid affords 1,2,3-benzthiadiazole-1-oxide, 13.The thermal stability of 13 up to 135 deg C, together with EPR evidence which disfavors an aryldiazenyl radical precursor, discount 13 as an intermediate in the formation of benzoxathiete 14 or its valence tautomer 17 during aprotic diazotization of the sulfinylanilines.Electron paramagnetic resonance evidence in conjunction with spin trapping indicates an intermediate arylaminyl radical.This evidence, taken together with ab initio calculations of optimized geometries energies and energy differences for biradical intermediate 15, favors a mechanism of formation of benzoxathiete 14 via aryldiazoate anhydrite 5 thence to rapid ring closure of carbon-centered radical 8.Further oxidation of 1,2,3-benzthiadiazole-1-oxide, 13, with hydrogen peroxide in methanol - acetic acid affords biphenylene and dibenzo-1,4-oxathiane-S-oxide, 38.Rose bengal sensitized photooxidation of 1,2,3-benzthiadiazole affords 13, biphenylene, and 38.Formation of the latter, in which one of the original S-O bonds has been broken, requires the formation of benzoxathiete-S-oxide, 34, and its rapid valence tautomerism to ketosulfine 36 and (2 + 4) cycloaddition of 36 to the simultaneously generated dehydrobenzene to give 38.Both ring closure of singlet biradical 35 to 34 and valence tautomerism of the latter to 36 are predicted by ab initio calculations to be facile and exothermic.In contrast to the aprotic diazotization of 2-anilines, the reaction of isoamyl nitrite with the corresponding sulfonyl anilines may plausibly follow a mechanism via 1,2,3-benzthiadiazole-1,1-dioxide 33 owing to the thermal instability of the latter and supported by ab initio treatments of the energetics of the processes involved.In addition EPR evidence, in conjunction with spin trapping of carbon centered radicals, support the viability of the pathway via 23, 25, 28, and 16 to biphenylene 20.The ab initio calculations of the energy differences between the reaction intermediates and estimates of the activation energies elucidated several aspects of these novel reaction.
- Naghipur, Ali,Reszka, Krzysztof,Lown, J. William,Sapse, Anne-Marie
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p. 1950 - 1960
(2007/10/02)
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- Ozonization of phenothiazine and its analogues
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When phenothiazine and phenoxazine were ozonized in dichloromethane, the cation radicals and the ozonate anion radicals were detected, whereas, in the ozonization of phenoxathiin and thianthrene, these radicals were not observed. Formation of these radicals was more favorable as greater was the polarity of the solvent and lower was the oxidation potential of the substrate. Ozonization of phenothiazine and phenoxazine in polar solvents was explained by the electron-transfer mechanism accompanied by the electrophilic ozone attack, and that of phenoxathiin and thianthrene by the electrophilic ozone attack alone.
- Matsui,Miyamoto,Shibata,Takase
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p. 2526 - 2530
(2007/10/02)
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- MILD AND SELECTIVE OXYGEN ATOM TRANSFER: n-Bu4NIO4 WITH METALLOPORPHYRINS
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Tetrabutylammonium periodate, n-Bu4NIO4, is a potent oxygen atom donor to substrates in the presence of catalytic amount of metalloporphyrin under neutral and homogeneous conditions, the results obtained suggesting the formation of oxo-metalloporphyrin as an active oxidizing intermediate.
- Takata, Toshikazu,Ando, Wataru
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p. 3631 - 3634
(2007/10/02)
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