- Tert-Butyl Nitrite Mediated Expeditious Methylsulfoxidation of Tetrazole-amines with DMSO: Metal-free Synthesis of Antifungal Active Methylsulfinyl-1H-tetrazole Derivatives
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A tert-butyl nitrite mediated methyl-sulfoxidation of tetrazole-amines in neat DMSO or methyl-sulfinyl derivatives is revealed for the first time. The reaction exhibits good group tolerance, as well as highly selectivity to sulfinyl substitutions. This new protocol provides an expeditious and operationally simple procedure for C?S(O) bond construction. Preliminary bioactivity evaluation on selected products shows promising antifungal activities. (Figure presented.).
- Dai, Peng,Luo, Kai,Yu, Xiang,Yang, Wen-Chao,Wu, Lei,Zhang, Wei-Hua
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- Stereospecific Reductive Desulfinylation of 1-Aryl-2-(methylsulfinyl)-2-(methylthio)ethenes with Grignard Reagents
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(E)-1-Aryl-2-(methylsulfinyl)-2-(methylthio)ethene, obtained by the Knoevenagel-type condensation of methyl (methylthio)methyl sulfoxide with the corresponding aromatic aldehyde, was found to react with ethylmagnesium chloride to give (Z)-1-aryl-2-(methylthio)ethene predominantly.Since the reaction of (Z)-1-(methylsulfinyl)-1-(methylthio)-2-phenylethene afforded (E)-1-(methylthio)-2-phenylethene, the present reaction appeared to be stereospecific.
- Ogura, Katsuyuki,Arai, Kazutaka,Tsuchihashi, Gen-ichi
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- Calix[4]arene-based (hemi)carcerands and carceplexes: Synthesis, functionalization, and molecular modeling study
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The synthesis of 11 calix[4]arene-based carceplexes obtained by solvent or doped inclusion is reported. Carceplexes with amides, for example, DMF, NMP, and 1,5-dimethyl-2-pyrrolidinone, and sulfoxides, for example, DMSO and thiolane-1-oxide, were obtained by solvent inclusion. In these cases the yield of the carceplex decreases with increasing guest size. Potential guests that do not form carceplexes by solvent inclusion, such as 2-butanone and 3-sulfolene, could be incarcerated by doped inclusion with 1.5-dimethyl-2-pyrrolidinone as a solvent 'doped' with 5-15 vol% of potential guest. The amide bridges of the carceplexes were converted into thioamide bridges in essentially quantitative yield by means of Lawesson's reagent in refluxing xylene. The dynamic properties of the incarcerated guests were examined by 2D NMR spectroscopy. Whereas for most guests a preference for one orientation inside the calix[4]arene-based (thia)carcerands was observed, for DMA, NMP, and ethyl methyl sulfoxide inside calix[4]arene-based (thia)carcerands two different orientations were present. The energy barriers for interconversion between the various orientations of DMA, NMP, and ethyl methylsulfoxide inside calix[4]arene-based (thia)-carcerands were determined with 2D EXSY NMR. The energy barriers are higher for the thiacarcerands than for the corresponding careerands with amide bridges. This may be due to the stronger hydrogen-bond-donating character of the thioamide group. Furthermore, molecular modeling simulations indicate that in case of the thiacarcerand the cavity is smaller as a result of a smaller diametrical distance between the NH atoms. Our results demonstrate that molecular modeling can be used to estimate the energy barriers for interconversion; the calculated activation energies showed good quantitative agreement with the experimental values.
- Van Wageningen, Andre M. A.,Timmerman, Peter,Van Duynhoven, John P. M.,Verboom, Willem,Van Veggel, Frank C. J. M.,Reinhoudt, David N.
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- Poly(ethylene) glycol as a green and reusable solvent in the oxidation of sulfides to sulfoxides using NaClO
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This article describes selective oxidation of a range of sulfides to the corresponding sulfoxides in good yields by NaClO in poly(ethylene) glycol as a green and reusable solvent using sulfuric acid as an efficient acid catalyst. The new method compares favorably with previous methods in literature. A separable mixture of two new diastereoisomers is reported. Copyright Taylor & Francis Group, LLC.
- Amoozadeh, Ali,Nemati, Firouzeh
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- Synthesis and characterization of 3-[N,N′-bis-3-(salicylidenamino) ethyltriamine] Mo(vi)O2@SBA-15: A highly stable and reusable catalyst for epoxidation and sulfoxidation reactions
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The efficient and reusable oxidation catalyst 3-[N,N′-bis-3- (salicylidenamino)ethyltriamine] Mo(vi)O2@SBA-15 has been synthesized by the anchoring of the 3-[N,N-bis-3-(salicylidenamino)ethyltriamine] ligand (L or Salpr) on the inner surfaces of organofunctionalized SBA-15 and subsequent complexation with Mo(vi)O2(acac)2. The physico-chemical properties of the functionalized catalysts were analyzed by elemental analysis, ICP-OES, XRD, N2-sorption measurements, TG & DTA, solid state 13C, 29Si NMR spectroscopy, FT-IR, Raman spectroscopy, XPS, DRS UV-Vis spectroscopy, SEM and TEM. XRD and N2 sorption analyses helped to find out the morphological and textural properties of the synthesized catalysts and confirm that an ordered mesoporous channel structure was retained even after the multistep synthetic procedures. The (100), (110) and (200) reflections in SBA-15 provide hints of a good structural stability, the existence of long range ordering and a high pore wall thickness. TG and DTA results reveal that the thermal stability of (L)Mo(vi)O2@SBA-15 was maintained up to 300°C. The organic moieties anchored over the surface of the SBA-15 support were determined by solid state 13C NMR and FT-IR spectroscopy. Further, solid state 29Si NMR spectroscopy provides the information about the degree of functionalization of the surface silanol groups with the organic moiety. The electronic environment and the oxidation state of the molybdenum site in (L)Mo(vi)O2@SBA-15 were monitored by Raman spectroscopy, XPS and DRS UV-Vis techniques. Moreover, the morphology and topographic information of the synthesized catalysts were confirmed by SEM and TEM imaging. The synthesized catalysts were evaluated in epoxidation and sulfoxidation reactions, and the results show that (L)Mo(vi)O2@SBA-15 exhibits high conversion and selectivity towards epoxidation and sulfoxidation reactions in combination with high stability. The anchored solid catalysts can be recycled effectively and reused several times without major loss in activity. In addition, Sheldon's hot filtration test was also carried out.
- Lazar, Anish,Thiel, Werner R.,Singh
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- Sulphoxidation of ethyl methyl sulphide, 4-chlorophenyl methyl sulphide and diphenyl sulphide by purified pig liver flavin-containing monooxygenase
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1. The biotransformation of ethyl methyl sulphide (EMS), 4-chlorophenyl methyl sulphide (CPMS) and diphenyl sulphide (DPS) to their corresponding sulphoxides by purified flavin-containing monooxygenase (FMO) is described. 2. Purified pig liver flavin-containing monooxygenase catalysed the sulphoxidation of EMS, CPMS and DPS to their corresponding sulphoxides and the reactions followed single enzyme Michelis-Menten kinetics. 3. The apparent Km and Vmax for the sulphoxidation of EMS were 1.38 ± 0.05 mM and 78.74 ± 3.9 nmoles mg-1 protein min-1, respectively. The apparent Km and Vmax for the sulphoxidation of CPMS were 0.185 ± 0.03 mM and 103 ± 5.0 nmoles mg-1 protein min-1, respectively. The apparent Km and Vmax for the sulphoxidation of DPS were 0.068 ± 0.002 mM and 49.26 ± 2.05 nmoles mg-1 protein min-1, respectively. 4. A significant reduction of the sulphoxidation of these simple sulphides was observed with addition of 1-naphthylthiourea in the incubation medium. On the other hand, incorporation of catalase and superoxide dismutase into the incubation media produced no appreciable inhibition of the observed sulphoxidation of the sulphides. 5. These results suggest that FMO is responsible, at least in part, for the sulphoxidation of nucleophilic sulphides as well as for the oxidation of sulphur atoms that reside within or adjacent to aromatic systems.
- Nnane, Ivo P.,Damani
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- A Tricopper(I) Complex Competent for O Atom Transfer, C-H Bond Activation, and Multiple O2 Activation Steps
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Oxygenation of a tricopper(I) cyclophanate (1) affords reactive transients competent for C-H bond activation and O atom transfer to various substrates (including toluene, dihydroanthracene, and ethylmethylsulfide) based on 1H NMR, gas chromatography/mass spectrometry (MS), and electrospray ionization (ESI)/MS data. Low product yields (1H NMR, and density functional theory (DFT) results for reaction of 1 with O2 are consistent with transient peroxo- and di(oxo)-bridged intermediates. DFT calculations elucidate a concerted proton-coupled electron transfer from toluene to the di(μ-oxo) intermediate and subsequent radical rebound as the C-H activation mechanism. Our results support a multicopper oxidase-like mechanism for O2 activation by 1, traversing species similar to the coplanar Cu3O2 unit in the peroxy and native intermediates.
- Cook, Brian J.,Di Francesco, Gianna N.,Kieber-Emmons, Matthew T.,Murray, Leslie J.
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- Eight-membered ring petal-shaped V8 cluster: An efficient heterogeneous catalyst for selective sulfur oxidation
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An eight-membered ring petal-shaped cluster [V8ⅣO8(CH3O)16(C2O4)](C6NH16)2(CH3OH)2 (V8) has been successfully designed and synthesized via hydrothermal method. Structure analysis revealed that each vanadium atom was in an octahedral geometrical configuration six-coordinated, two adjacent vanadium atoms were linked by oxygen atoms on oxalic acid to form a ring. The selective sulfur oxidation experiments reveal that V8 had good catalytic activity under mild conditions, and the removal rate of phenyl sulfide was >99% within 4 h at 40 °C. In addition, the open aperture Z-scan test of V8 was carried out and found that V8 also has latent application value as nonlinear optical (NLO) material.
- Ping, Qing-Dong,Cao, Jia-Peng,Han, Ye-Min,Yang, Mu-Xiu,Hong, Ya-Lin,Li, Jia-Nian,Wang, Ji-Lei,Chen, Jia-Li,Mei, Hua,Xu, Yan
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- Correlating the role of hydrophilic/hydrophobic nature of Rh(I) and Ru(II) supported organosilica/silica catalysts in organotransformation reactions
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Highly reactive and hydrophobic triphenyl phosphine based rhodium(I) and ruthenium(II) organometallic complexes over benzene containing periodic mesoporous organosilica (PMOB) have been synthesized. This has been achieved by the immobilization of neat metal complexes like RhCl(PPh3)3 [Wilkinson catalyst], RuHCl(CO)(PPh3)3 and RuCl2(PPh3)3 over aminofunctionalized PMOB to get RhCl(PPh3)2-PrNH2PMOB, RuHCl(CO)(PPh3)2-PrNH2PMOB and RuCl2(PPh3)3-PrNH2PMOB, respectively. The physico-chemical properties of the functionalized catalysts were analyzed by elemental analysis, ICP-OES, XRD, N2 sorption analyses, FT-IR, solid state 13C and 29Si NMR spectra, XPS, SEM, TEM and contact angle measurements. The XRD and N2 sorption analyses showed excellent textural properties with ordered mesoporous channel structure of all synthesized catalysts. The organic moieties anchored in PMOB were confirmed by 13C CPMAS NMR and FT-IR spectroscopy with 29Si CPMAS NMR spectroscopy providing the information about the degree of functionalization of surface silanol groups with organic moiety. The Rh(I) and Ru(II) complexes supported on MCM-41/SBA-15/PMOE (ethane-PMO) were synthesized, and their catalytic activities in hydrogenation and sulfoxidation reactions were compared with Rh(I) and Ru(II) complexes supported on PMOB. The results show that PMOB based catalysts exhibit higher activities and selectivities than MCM-41/SBA-15/PMOE supported catalysts, neat homogeneous complexes and without catalyst. The better catalytic performance of PMOB based catalyst is attributed to the hydrophobic nature and high surface area of the PMOB support. The recycling studies of anchored catalysts show no major deactivation of the catalyst.
- Lazar, Anish,George, Shoy C.,Jithesh,Vinod,Singh
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- A clean, mild, and selective oxidation of sulfides to sulfoxides using NaClO/H2SO4 in Aqueous Media
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A range of sulfides can be selectively oxidized to the corresponding sulfoxides in good yields using NaClO/H2SO4 in both water and 50:50 water:EtOH as solvent. Two new compounds are reported that show a diastereoselective oxidation in 2-phenylthioalcohols with possible neighboring hydroxyl group participation with a logic proposed mechanism. Taylor & Francis Group, LLC.
- Amoozadeh, Ali,Nemati, Firouzeh
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- Deep eutectic solvent-assisted synthesis of highly efficient nanocatalyst (n-TiO2@TDI@DES (ZnCl2:urea)) for chemoselective oxidation of sulfides to sulfoxides
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This study proposed a straightforward process to synthesize 2,4-toluene diisocyanate (TDI)-functionalized TiO2 nanoparticles in which a cost-effective linker (TDI) with high reactivity was employed to couple nano-TiO2 through covalent bonding to a deep eutectic solvent (DES). By this method, DES was successfully immobilized on the TiO2@TDI surface as an adsorbent and stabilizer. The structural, morphological, and physicochemical characteristics of the synthesized nanocatalysts were evaluated using various analytical methods including Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM–EDX), and elemental analysis. The heterogeneity of the catalyst was also examined by a hot filtration test. The obtained TiO2@TDI@DES nanoparticles offered superior catalytic behavior and excellent yield as well as recyclability for the chemoselective oxidation of sulfide into sulfoxide using a green oxidant (hydrogen peroxide). This catalyst exhibited excellent reusability as it can be recovered for six successive cycles with no significant leach or reduction of catalytic efficiency.
- Taghavi, Shaghayegh,Amoozadeh, Ali,Nemati, Firouzeh
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- Assembly of a Hexameric Cluster of Polyoxomolybdotriphosphonate Builts from [Zn(H2O){TeMo6O21}{N(CH2PO3)3}]6-Subunits and Its Optical and Catalytic Properties
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The crown-shaped organotriphosphonate-modified 36-molybdenum cluster (NH4)18Na7H11[Zn(H2O)TeMo6O21{N(CH2PO3)3}]6·23H2O (1) has been synthesized, which is the largest zinc-containing organophosphonate-based polyoxometalate to date. Compound 1 was prepared in buffer solution (pH 5.5) with heptamolybdate and amino trimethylene phosphonic acid (ATMP) as the organic ligand. The polyanion constructed from a hexmeric assembly of [Zn(H2O){TeMo6O21}{N(CH2PO3)3}]6- subunits has been fully investigated by a few characterization methods. In this work, we discovered that 1 exhibited reversible photochromism and it changed from white to reddish brown upon UV irradiation. In addition, compound 1, as a catalyst, can oxidize sulfides to sulfoxides, showing a high yield/conversion and a good selectivity.
- Kong, Hui,Li, Keli,Liu, Siyu,Ma, Pengtao,Niu, Jingyang,Wang, Jingping,Wang, Yaqiong,Xu, Qian
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p. 15759 - 15767
(2021/10/20)
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- 36-Nuclearity Organophosphonate-Functionalized Polyoxomolybdates: Synthesis, Characterization and Selective Catalytic Oxidation of Sulfides
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The crown-shaped 36-molybdate cluster organophosphonate-functionalized polyoxomolybdates with the highest nuclearity in organophosphonate-based polyoxometalate chemistry, (NH4)19Na7H10[Cu(H2O)TeMo6O21{N(CH2PO3)3}]6?31 H2O, has been reported for the first time. The synthesized 36-molybdate cluster was characterized by routine techniques and tested as a heterogeneous catalyst for selective oxidation of sulfides with impressive catalytic and selective performances after heat treatment. High efficiency (TON=15333) was achieved in the selective oxidation of sulfides to sulfoxides, caused by the synergic effect between copper and polyoxomolybdates and the generation of the cuprous species during the heat treatment.
- Xu, Qiaofei,Liang, Xinmiao,Xu, Baijie,Wang, Jiawei,He, Peipei,Ma, Pengtao,Feng, Jiwen,Wang, Jingping,Niu, Jingyang
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p. 14896 - 14902
(2020/10/19)
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- Accurate Regulating of Visible-Light Absorption in Polyoxotitanate-Calix[8]arene Systems by Ligand Modification
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With use of a macrocyclic polyphenol, tert-butylcalix[8]arene (TBC[8]), as ligands, a series of TBC[8]-stabilized {Ti4O2}clusters, containing penta- and hexacoordinated Ti centers, were synthesized. Such complexes are "core-shell" shaped containing a {Ti4O2} core arranged in a zigzag fashion. While outer walls of the clusters are decorated by deprotonated TBC[8], their upper and lower surfaces can be modified by various O- or N-donor ligands, and the ratio of the penta- and hexacoordinated Ti(IV) centers in the {Ti4O2} core can be precisely regulated from 4:0, to 3:1, to 2:2, to 1:3, and finally to 0:4. The combined coordination of different ligands in the axial direction shows significant influence on the adsorption of the TBC[8]-Ti4 system in the visible-light region, and their absorption edge can be precisely regulated from 600 to 700 nm. The above structural functionalization in the TBC[8]-Ti4 system also tunes their photocatalytic H2 production activities and oxidative desulfurization ability. Thus, for the first time, by confining the polyoxotitanium cluster in macrocyclic molecules, we provide an example of understanding the structure-property relationship of titanium-oxygen materials by ligand modification.
- Liu, Chao,Yang, Xin-Xue,Yi, Xiao-Yi,Yu, Wei-Dong
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- Vanadium (IV) complexes with Schiff base ligands derived from 2,3-diaminopyridine as catalyst for the oxidation of sulfides to sulfoxides with H2O2
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Sulfoxides are substances used in the synthesis of valuable complexes and as drugs in medicine. Sulfides were selectively oxidized to the corresponding sulfoxides in proper yields with (H2O2) hydrogen peroxide applying a vanadium (IV) Schiff base complex in the role of a catalyst in glacial acetic acid in the role of solvent beneath mild conditions. For the conversion of sulfides to sulfoxides of various catalysts are applied. It must be noted that in our previous article, the vanadyl complexes (VOY1) synthesized were applied as a catalyst in the epoxidation of styrene (Zabardasti and Shangaie, J Iran Chem Soc 13:1875–1886, 2016) but in the new work, vanadium (IV) complexes with Schiff base ligands derived from 2,3-diaminopyridine were used to as catalyst for the oxidation of sulfides to sulfoxides with H2O2. To the most of our information, there is not any literature description on the selective oxidation of sulfides to sulfoxides by means of a vanadium (IV) Schiff base complex with N, O donor ligand derived from 2,3-diaminopyridine catalyst beneath these conditions. Dimethyl sulfide was chosen as a pattern substrate for optimization experiments. Oxidation of sulfides was functioned at 25?°C temperature in the attendance of a catalytic quantity of the vanadium (IV) complex or (VOY1) utilizing 20% H2O2 in the role of the oxidant, Scheme 1 and glacial acetic acid in the role of the solvent.
- Zabardasti, Abedien,Shangaie, Sayed Asad
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- Nickel(II) Schiff base complex supported on nano-titanium dioxide: A novel straightforward route for preparation of supported Schiff base complexes applying 2,4-toluenediisocyanate
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For the first time, a novel, straightforward and inexpensive route for immobilization of metals in Schiff base complex form is reported applying 2,4-toluenediisocyanate as a precursor of primary amine group. A nickel(II) Schiff base complex supported on nano-TiO2 was designed and synthesized as an effective heterogeneous nanocatalyst for organic reactions, and well characterized using various techniques such as Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray analysis and thermogravimetric analysis. The catalytic efficiency of the complex was evaluated in selective oxidation of sulfide to sulfoxide by hydrogen peroxide as an oxidant under solvent-free conditions at room temperature, which successfully resulted in high yield and high conversion of products. Effective factors including solvent type, oxidant and catalyst amount were also optimized. The catalyst shows outstanding reusability and could be impressively recovered for six consecutive cycles without significant change of its catalytic efficiency.
- Amoozadeh, Ali,Tabrizian, Elham,Shahjoee, Saeedeh
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- Ionic Liquid Stabilized Niobium Oxoclusters Catalyzing Oxidation of Sulfides with Exceptional Activity
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We present here a new class of niobium oxoclusters that are stabilized effectively by carboxylate ionic liquids. These functionalized ILs are designated as [TBA][LA], [TBA][PA], and [TBA][HPA] in this work, in which TBA represents tetrabutylammonium and LA, PA, and HPA refer to lactate, propionate, 3-hydroxypropionate anions, respectively. The as-synthesized Nb oxoclusters have been characterized by use of elemental analysis, NMR, IR, XRD, TGA, HRTEM. It was found that [TBA][LA]-stabilized Nb oxoclusters (Nb?OC@[TBA][LA]) are uniformly dispersed with an average particle size of 2–3 nm and afforded exceptionally high catalytic activity for the selective oxidation of various thioethers. The turnover number with Nb?OC@[TBA][LA] catalyst was over 56 000 at catalyst loading as low as 0.0033 mol % (1 ppm). Meantime, the catalyst also showed the high activity for the epoxidation of olefins and allylic alcohols by using only 0.065 mol % of catalyst (50 ppm). The characterization of 93Nb NMR spectra revealed that the Nb oxoclusters underwent structural transformation in the presence of H2O2 but regenerated to their initial state at the end of the reaction. In particular, the highly dispersed Nb oxoclusters can absorb a large amount of polar organic solvents and thus were swollen greatly, which exhibited “pseudo” liquid phase behavior, and enabled the substrate molecules to be highly accessible to the catalytic center of Nb oxocluster units.
- Zhou, Qingqing,Ye, Man,Ma, Wenbao,Li, Difan,Ding, Bingjie,Chen, Manyu,Yao, Yefeng,Gong, Xueqing,Hou, Zhenshan
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p. 4206 - 4217
(2019/03/26)
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- PYRROLO[2,3-C]PYRIDINE DERIVATIVE, PREPARATION METHOD THEREFOR, AND USE THEREOF IN MEDICINE
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Disclosed are a pyrrolo[2,3-c]pyridine derivative, a preparation method therefor, and use thereof in medicine. Specifically, disclosed are a pyrrolo[2,3-c]pyridine derivative as represented by general formula (1), a preparation method therefor, a pharmaceutical composition comprising the derivative, as well as use thereof as a BRD4 inhibitor in the treatment of related diseases such as cancers, inflammations, chronic liver diseases, diabetes, cardiovascular diseases and AIDS, each substituent in general formula (I) being same as defined in the description.
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Page/Page column 38; 149
(2018/08/03)
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- Nano-sized glass as an economically viable and eco-benign support to anchor heteropolyacids for green and sustainable chemoselective oxidation of sulfides to sulfoxides
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Abstract: In this work, glass wastes were employed as cost-effective supports for the immobilization of phosphomolybdic acid (5–25 wt.% PMA) through an impregnation method. The highly efficient and retrievable nanocatalyst named nano-glass waste-supported phosphomolybdic acid (n-GW/PMA) was fully characterized by several techniques such as: XRD, FE-SEM, EDX, FT-IR and TGA. The catalytic performance of the as-synthesized heterogeneous nanocatalyst was effectively investigated for the chemoselective oxidation of sulfides to sulfoxides in the presence of 30% H 2O 2 as an oxidant at room temperature under solvent-free condition. Optimization of the reaction conditions was performed by means of central composite design (CCD), which is one of the powerful response surface methodologies. Based on the results obtained under the optimum condition, the sample of 16 wt.% of PMA loading offered high conversion rates and yields (97%). Besides, the beneficial points of the prepared catalyst were its recoverability and reusability for several reaction cycles, low-cost and toxicity, easy availability and facile production. Graphical abstract: Nano-glass waste-supported phosphomolybdic acid (n-GW/PMA) was synthesized as a novel, highly efficient and retrievable nanocatalyst for the chemoselective, green and rapid oxidation of sulfides to sulfoxides through an experimental design (CCD) approach. The prepared catalyst was characterized by FT-IR, TGA, XRD, FE-SEM and EDX techniques. [Figure not available: see fulltext.].
- Zolfagharinia, Somayeh,Kolvari, Eskandar,Koukabi, Nadiya,Hosseini, Maliheh M
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p. 1411 - 1421
(2017/09/25)
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- The Polyoxovanadate-Based Carboxylate Derivative K6H[VV17VIV12(OH)4O60(OOC(CH2)4COO)8]·nH2O: Synthesis, Crystal Structure, and Catalysis for Oxidation of Sulfides
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The high-nuclearity polyoxovanadate-based carboxylate derivative K6H[VV17VIV12(OH)4O60(OOC(CH2)4COO)8]·nH2O (1) has been successfully synthesized by conventional aqueous methods and structurally characterized. The [VV17VIV12(OH)4O60(OOC(CH2)4COO)8]7- polyanion is built up from three cages: one {VV17(OH)4O44} cage and two identical [(VIV3O6)2(OOC(CH2)4COO)4]8- cages. Of the three cages, the {VV17(OH)4O44} is a purely inorganic polyoxovanadate cluster, whereas each of the [(VIV3O6)2(OOC(CH2)4COO)4]8- cages is a vanadium-based organic-inorganic hybrid cluster framed via four adipate ligands linking simultaneously to two triangular {V3} units. The two [(VIV3O6)2(OOC(CH2)4COO)4]8- cages are covalently attached to the central {VV17(OH)4O44} cage via V-O-V bonds in a linear arrangement, resulting in a {V29}-based hybrid cluster skeleton. The catalytic properties of compound 1 for the oxidation of sulfides by tert-butyl hydroperoxide were investigated, and the result indicates that 1 exhibits excellent catalytic activity for the oxidation of sulfides under mild conditions.
- Wang, Ke,Niu, Yanjun,Zhao, Dongyan,Zhao, Yanxin,Ma, Pengtao,Zhang, Dongdi,Wang, Jingping,Niu, Jingyang
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p. 14053 - 14059
(2017/11/27)
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- Sulfamic acid-functionalized nano-titanium dioxide as an efficient, mild and highly recyclable solid acid nanocatalyst for chemoselective oxidation of sulfides and thiols
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A highly efficient and retrievable titanium dioxide-based nanocatalyst has been synthesized by covalent grafting of chlorosulfonic acid on amine-functionalized titania as a novel inorganic-organic hybrid heterogeneous nanocatalyst, which was characterized by Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The acid strength of the catalyst was determined by pH analysis and the Hammett acidity function. The potential of the resultant nanocatalyst was effectively evaluated for the chemoselective oxidation of sulfides to sulfoxides and thiols to disulfides using 30% H2O2 as an oxidant at room temperature under solvent-free conditions, which led to high conversion rates and yields. Optimization of the reaction conditions was studied by central composite design (CCD), which is one of the most widely used response surface methodologies. The catalyst can be easily recycled up to 10 times without significant decrease in catalytic activity, which makes it a promising catalyst for practical and large-scale applications. This work is the first report that uses 2,4-toluene diisocyanate as a linker for immobilizing liquid acid on a support.
- Tabrizian, Elham,Amoozadeh, Ali,Rahmani, Salman
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p. 21854 - 21864
(2016/03/08)
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- Magnetic nanoparticle-supported imidazole tribromide: a green, mild, recyclable and metal-free catalyst for the oxidation of sulfides to sulfoxides in the presence of aqueous hydrogen peroxide
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Imidazole tribromide immobilized on magnetic nanoparticles as a bromine source was prepared and characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) techniques. The high catalytic activity of this novel catalyst was investigated in the oxidation of sulfides to sulfoxides using aqueous hydrogen peroxide as an oxidant at room temperature under solvent-free conditions. More importantly, the catalyst could be easily recovered by an external magnet and reused five times without any significant loss of catalytic activity.
- Otokesh, Somayeh,Kolvari, Eskandar,Amoozadeh, Ali,Koukabi, Nadiya
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p. 53749 - 53756
(2015/06/30)
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- IBX works efficiently under solvent free conditions in ball milling
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IBX (2-iodoxybenzoic acid), discovered in 1893, is an oxidant in synthetic chemistry whose extensive use is impeded by its explosiveness at high temperature and poor solubility in common organic solvents except DMSO. Since the discovery of Dess-Martin Periodinane in 1983, several modified IBX systems have been reported. However, under ball milling conditions, IBX works efficiently with various organic functionalities at ambient temperature under solvent free conditions. Also, the waste IBA (2-iodosobenzoic acid) produced from the reactions was in situ oxidized to IBX in the following step using oxone and thus reused for multiple cycles by conserving its efficiency (only ～6% loss after 15 cycles). This work describes an overview of a highly economical synthetic methodology which overcomes the problems of using IBX, efficiently in gram scale and in a non-explosive way. This journal is the Partner Organisations 2014.
- Achar, Tapas Kumar,Maiti, Saikat,Mal, Prasenjit
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p. 12834 - 12839
(2014/04/03)
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- TiIV exchanged K10-montmorillonite: Characterisation and catalytic properties in liquid-phase sulfide oxidation
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Titanium-containing K10 has been synthesised and characterised by X-ray diffraction, UV-visible reflectance, solid state NMR spectroscopy, N2 nitrogen adsorption at 77K and chemical analysis. Two different titanium species have identified with a high dispersion in K10. The first is in an isolated penta- and hexa-coordinated state and the second is in the form of polymerised hexacoordinated species, which contains Ti-O-Ti bonds. These titanium species were found to be the catalytic sites that readily interact with oxidant to offer an active and selective catalytic system for the oxidation of sulfides. This catalytic system was studied in the asymmetric oxidation of methyl phenyl sulfide, using different types of chiral modifier, and gives excellent conversion and sulfoxide selectivity, together with a significant enantioselectivity in the range of 16-18% ee with (R)-binol.
- Khedher,Ghorbel,Fraile,Mayoral
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experimental part
p. 604 - 608
(2010/02/28)
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- Oxidoperoxidotungsten(VI) complexes with secondary hydroxamic acids: Synthesis, structure and catalytic uses in highly efficient, selective and ecologically benign oxidation of olefins, alcohols, sulfides and amines with H2O2 as a terminal oxidant
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The reaction of a solution of freshly precipitated WO3 in H 2O2 separately with the secondary hydroxamic acids N-benzoyl-N-phenylhydroxamic acid (BPHAH), N-benzoyl-Northo-tolylhydroxamic acid (BOTHAH), N-benzoyl-N-meta-tolylhydroxamic acid (BMTHAH), N-benzoyl-N-para- tolyl-hydroxamic acid (BPTHAH) and N-cinnamyl-N-phenylhy-droxamic acid (CPHAH) afforded [WO(O2)(BPHA)2] (1), [WO(O2)(BOTHA) 2] (2), [WO(O2)(BMTHA)2] (3), [WO(O 2)-(BPTHA)2] (4) and [WO(O2)(CPHA)2] (5), respectively. Aqueous tungstate solution, on reaction with all these hydroxamic acids, produced [W(O)2(hydroxamato)2] (6). The complexes show excellent catalytic functions in the oxidation of (a) olefins at room temperature in the presence of NaHCO3 as promoter, (b) alcohols, sulfides and amines, at reflux, with H2O2 as a terminal oxidant, yielding a high turnover number (TON), the highest being for olefin-to-epoxide conversion. An attempt to synthesize peroxide-rich complexes of the type PPh4[WO(O2)2(hydroxamato)] (7), for example PPh4[WO-(O2)2BMTHA] (7C), resulted in the isolation of PPh4[WO-(O2)2(C 6H5COO)] (8), which was probably obtained by the hydrolysis of coordinated BMTHA. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Maiti, Swarup K.,Dinda, Subhajit,Banerjee, Surajit,Mukherjee, Alok K.,Bhattacharyya, Ramgopal
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experimental part
p. 2038 - 2051
(2009/03/11)
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- Oxoperoxo molybdenum(VI) and tungsten(VI) and oxodiperoxo molybdate(VI) and tungstate(VI) complexes with 8-quinolinol: Synthesis, structure and catalytic activity
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A solution obtained by dissolving MoO3 in a moderate excess of H2O2 reacts with 8-quinolinol (QOH) to give [MoO(O 2)(QO)2] (1), but, when the same reaction is conducted with a large excess of H2O2, an anionic complex is formed, which reacts with PPh4Cl to give the corresponding salt [MoO(O 2)2(QO)][PPh4] (2 · PPh4). Freshly prepared WO3 behaves the same way and, depending on the amount of H2O2 used, as above, produces either [WO(O 2)(QO)2] (3) or [WO(O2)2(QO)] [PPh4] (4 · PPh4), respectively. Crystallographic analyses reveal the coordination geometries around the metal center in these complexes to be distorted pentagonal bipyramids. These compounds show interesting catalytic properties in the oxidation of alcohols using H 2O2 as the terminal oxidant. In the case of aromatics, including benzylic and cinnamylic alcohols, the oxidation occurs selectively, affording aldehydes or ketones with reasonably high turnover numbers. Taking benzyl alcohol as a representative case, a probable mechanism of the alcohol-to-aldehyde conversion mediated by the prepared catalysts is suggested. The oxidation of aliphatic primary alcohols, under the same conditions, does not show the above selectivity: the reaction yields the corresponding aldehydes as well as carboxylic acids. The work was also extended to study the catalytic activity towards the oxidation of phenol and various sulfides and amines using the same oxidants. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2005.
- Maiti, Swarup K.,Banerjee, Surajit,Mukherjee, Alok K.,Abdul Malik,Bhattacharyya, Ramgopal
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p. 554 - 563
(2007/10/03)
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- Liquid-phase oxidation of sulfides by an aluminum (and titanium) tert-butoxide - tert-butyl hydroperoxide system
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A system aluminum (and titanium) tert-butoxide-tert-butyl hydroperoxide (1 : 2) under mild conditions (20°C, 1 h) oxidizes aliphatic and alkylaromatic sulfides and diphenyl sulfide to the corresponding sulfones in yields close to ～100%. The oxidation is induced by electron-excited dioxygen formed upon thermal decomposition of intermediate metal-containing peroxy trioxides (ozonides). The latter are formed as a result of the reversible reaction of aluminum or titanium tert-butoxides with tert-butyl hydroperoxide followed by the interaction of di-tert-butoxy-tert-butylperoxyaluminum and tri-tert-butoxy-tert-butylperoxytitanium that formed with another Bu tOOH molecule. Alkminum-containing peroxide (ButO) 2AlOOBut oxidizes sulfides to sulfoxides.
- Dodonov,Zaburdaeva,Stepovik
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p. 1729 - 1734
(2007/10/03)
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- Compositions useful for transferring therapeutically active substances into a target cell, and their use in gene therapy
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The present invention relates to a composition which is intended for transferring at least one therapeutically active substance into the interior of a target cell, characterized in that it comprises a mixture of at least one therapeutically active substance and at least one polar compound which is selected from a specific group of aprotic polar compounds. The therapeutically active substance is preferably a polynucleotide, and the polar compound is DPSO, which improves the ability of the polynucleotide to be transfected into the interior of the cells. The compositions according to the invention can be used as a diagnostic therapeutic, prophylactic or vaccinal medicament for treating the human or animal body by means of gene therapy.
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- Steric and Resonance Effects on the Kinetics of Oxidation of Organic Sulfides by Quinolinium Fluorochromate
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Kinetics of oxidation of dialkyl, alkyl phenyl and benzal methyl phenyl sulfides to their sulfoxides by quinolinium fluorochromate (QFC) have been followed in aqueous acetic acid. The order of the reaction is found to be one each with respect to QFC, H3O+ and the sulfide. Increase in the dielectric constant of the medium decreases the rate, while variation in ionic strength has no perceptible change in the rate. The steric effect plays a dominant role to decide the rate of the reaction rather than the inductive effect. In the case of benzal methylphenyl sulfide, the larger rate is due to the resonance effect. Attack of protonated QFC on the organic sulfide in a slow step, is rate-determining one.
- Karunakaran, Kulandaivelu,Gurumurthy, Rajagopala,Elango, Kuppannagounder Pitchaimuthu
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p. 297 - 299
(2007/10/03)
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- Discovery, characterisation, and utilisation of selenoxide-sulfonic acid salts: A new class of selenoxide-based oxidant and stable selenoxide equivalent
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The preparation and characterisation of a novel class of salts of selenoxides with sulfonic acids are described. They are readily prepared by simple addition of the sulfonic acid to a solution of selenoxide, and removal of solvent. In most cases they are colourless crystalline solids and are considerably more stable than the parent selenoxides, allowing full characterisation and X-ray crystallographic analysis. They also efficiently oxidise sulfides to sulfoxides, with no overoxidation, and clean regeneration of selenide. Their structure has been confirmed by 1H NMR spectroscopy and X-ray crystallography.
- Procter, D. John,Thornton-Pett, Mark,Rayner, Christopher M.
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p. 1841 - 1854
(2007/10/03)
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- THE REACTIVITY OF SUPEROXIDE: A POTENT OXIDANT GENERATED IN SITU FROM SUPEROXIDE AND CO2
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The reaction of CO2 with superoxide cooxidized sulfides and olefins to the corresponding sulfoxides and epoxides, respectively, in dimethylformamide.The peroxy intermediates, CO4.- and C2O6.-, generated in situ from superoxide and CO2, were proposed as the ultimate oxidants in the oxidations.
- Yamamoto, Hiroshi,Mashino, Tadahiko,Nagano, Tetsuo,Hirobe, Masaaki
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p. 4133 - 4136
(2007/10/02)
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- A NEW SOURCE FOR GENERATION OF BENZYNE AND PYRIDYNE: REACTIONS OF O-HALOPHENYL (OR 3-BROMO-4-PYRIDYL) PHENYL SULFOXIDES WITH GRIGNARD REAGENTS
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o-Chloro- and o-bromophenyl phenyl sulfoxides and (3-bromo-4-pyridyl) phenyl sulfoxide were treated with Grignard reagents to generate benzyne (or 3,4-pyridyne) in THF.The o-iodophenyl derivative, on the other hand, gave mainly o-(arylsulfinyl)phenyl Grignard reagent.
- Furukawa, Naomichi,Shibutani, Tadao,Fujihara, Hisashi
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p. 2727 - 2730
(2007/10/02)
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- An improved procedure for the methylation analysis of oligosaccharides and polysaccharides.
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An improved procedure for the methylation analysis of oligosaccharides and polysaccharides is described. Steps in the procedure were examined and optimised for quantitative recovery and speed. Methylation was shown to be complete by using [14C]methyl iodide. All operations were performed in the same tube and the need to concentrate solutions containing acetylated alditols of methylated sugars was eliminated, thus minimising losses due to volatilization. The method is convenient, gives high recoveries of acetylated alditols of methylated sugars, and allows analysis of the glycosyl linkages of oligo- or poly-saccharides to be completed within a working day. A wide range of oligo- and poly-saccharides were methylated by this procedure.
- Harris,Henry,Blakeney,Stone
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