1669-98-3Relevant articles and documents
Tert-Butyl Nitrite Mediated Expeditious Methylsulfoxidation of Tetrazole-amines with DMSO: Metal-free Synthesis of Antifungal Active Methylsulfinyl-1H-tetrazole Derivatives
Dai, Peng,Luo, Kai,Yu, Xiang,Yang, Wen-Chao,Wu, Lei,Zhang, Wei-Hua
, p. 468 - 473 (2018)
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.).
Calix[4]arene-based (hemi)carcerands and carceplexes: Synthesis, functionalization, and molecular modeling study
Van Wageningen, Andre M. A.,Timmerman, Peter,Van Duynhoven, John P. M.,Verboom, Willem,Van Veggel, Frank C. J. M.,Reinhoudt, David N.
, p. 639 - 654 (1997)
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.
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
Lazar, Anish,Thiel, Werner R.,Singh
, p. 14063 - 14073 (2014)
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.
A Tricopper(I) Complex Competent for O Atom Transfer, C-H Bond Activation, and Multiple O2 Activation Steps
Cook, Brian J.,Di Francesco, Gianna N.,Kieber-Emmons, Matthew T.,Murray, Leslie J.
, p. 11361 - 11368 (2018)
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.
Correlating the role of hydrophilic/hydrophobic nature of Rh(I) and Ru(II) supported organosilica/silica catalysts in organotransformation reactions
Lazar, Anish,George, Shoy C.,Jithesh,Vinod,Singh
, p. 138 - 146 (2016)
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.
Deep eutectic solvent-assisted synthesis of highly efficient nanocatalyst (n-TiO2@TDI@DES (ZnCl2:urea)) for chemoselective oxidation of sulfides to sulfoxides
Taghavi, Shaghayegh,Amoozadeh, Ali,Nemati, Firouzeh
, (2020/12/21)
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.
36-Nuclearity Organophosphonate-Functionalized Polyoxomolybdates: Synthesis, Characterization and Selective Catalytic Oxidation of Sulfides
Xu, Qiaofei,Liang, Xinmiao,Xu, Baijie,Wang, Jiawei,He, Peipei,Ma, Pengtao,Feng, Jiwen,Wang, Jingping,Niu, Jingyang
, p. 14896 - 14902 (2020/10/19)
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.