- Piperidin-1-ylamidomethyltellurium derivatives: Synthesis and solid state structures
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Oxidative insertion of low valent tellurium, Te(0) and Te(II), into the C–Br bond of α-bromoacetylpiperidine proceeds readily under mild conditions and provides a direct synthetic route to stable, crystalline piperidin-1-ylamidomethyltellurium(IV) dibromides, (C5H10NCOCH2)2TeBr2, 1b and (C5H10NCOCH2)ArTeBr2 (Ar?=?2,4,6-Me3C6H2, 2b; 1-C10H7, 3b; 4-MeC6H4, 4b). While the bisulfite reduction of 1b affords a yellow coloured telluroether, (C5H10NCOCH2)2Te, 1 as an oil, that of the unsymmetrical diorganotellurium dibromides, (C5H10NCOCH2)ArTeBr2 leads to the isolation of the respective diarylditellurides, ArTeTeAr. The symmetrical telluroether, 1 adds dihalogens oxidatively to give piperidin-1-ylamidomethyltellurium(IV) dihalides, (C5H10NCOCH2)2TeX2 (X?=?Cl, 1a; Br, 1b and I, 1c;). All the new piperidin-1-ylamidomethyltellurium derivatives have been characterized by elemental and 1H, 13C, 125Te NMR spectral analyses. Single-crystal X-ray diffraction data for 1b and 1c indicated a butterfly molecular shape for the two halo analogues in which the six-member heterocyclic rings in the organic ligands retain the chair conformation of the independent piperidine molecule. The piperidin-1-yl appended organic ligand invariably results in the amido O atom being involved in an intramolecular Te O secondary bonding interaction and acts as a small-bite (C, O) chelating agent, at least in the solid state. Steric congestion around the six-coordinate Te(IV) atom and the partial positive charge on N owing to the resonating character of the N[pdbdtd]C[pdbdtd]O amido group prevents these atoms from participating in the intermolecular associative forces. Instead, the weak C–H?O and C–H?Br interactions take centre-stage in the solid state self-assembly.
- Khan, Mariya,Misra, Shafalika,Srivastava, Ramesh C.,Chauhan, Ashok K.S.,Duthie, Andrew,Butcher, Ray J.
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- Modulating Chalcogen Bonding and Halogen Bonding Sigma-Hole Donor Atom Potency and Selectivity for Halide Anion Recognition
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A series of acyclic anion receptors containing chalcogen bond (ChB) and halogen bond (XB) donors integrated into a neutral 3,5-bis-triazole pyridine scaffold are described, in which systematic variation of the electronic-withdrawing nature of the aryl sub
- Beer, Paul D.,Docker, Andrew,Guthrie, Charles H.,Kuhn, Heike
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supporting information
p. 21973 - 21978
(2021/09/02)
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- Synthetic method of diaryl ditellurium ether compound
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The invention relates to a synthetic method of a diaryl ditellurium ether compound. The method comprises the following steps: putting phenylboronic acid or derivatives thereof, elemental tellurium, trimethylcyano silane and an organic solvent into a reaction container to obtain a mixed solution, heating the mixed solution to 110-140 DEG C, performing stirring to react for 18-30 hours at the temperature to obtain a reaction solution, and carrying out aftertreatment to obtain the diaryl ditellurium ether compound, the ratio of the phenylboronic acid or the derivative thereof to the elemental tellurium to the trimethylnitrile silane is (7-9): (8-10): 1. The synthetic method of the diaryl ditellurium ether compound has the following beneficial effects: 1, the reaction can be performed withoutmetal participation, so that the synthetic method is more environment-friendly and lower in cost; 2, the compatibility of a substrate is good; and 3, the preparation process is simple and easy to operate.
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Paragraph 0042-0056
(2021/03/31)
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- Tellurides Bearing Sulfonamides as Novel Inhibitors of Leishmanial Carbonic Anhydrase with Potent Antileishmanial Activity
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We report for the first time a novel series of tellurides bearing sulfonamide as selective and potent inhibitors of the β-class carbonic anhydrase (CA; EC 4.2.1.1) enzyme expressed in Leishmania donovani protozoa. Such derivatives showed high activity against axenic amastigotes, and among them, compound 5g (4-(((3,4,5-trimethoxyphenyl)tellanyl)methyl)benzenesulfonamide) showed an IC50 of 0.02 μM being highly selective for the parasites over THP-1 cells with a selectivity index of 300. The in vitro and in vivo toxicity experiments showed compound 5g to possess a safe profile and thus paving the way for tellurium-containing compounds as novel drug entities.
- Angeli, Andrea,Etxebeste-Mitxeltorena, Mikel,Sanmartín, Carmen,Espuelas, Socorro,Moreno, Esther,Azqueta, Amaya,Parkkila, Seppo,Carta, Fabrizio,Supuran, Claudiu T.
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p. 4306 - 4314
(2020/05/25)
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- Reactivity of Selenocystine and Tellurocystine: Structure and Antioxidant Activity of the Derivatives
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l-Selenocystine (5) and l-tellurocystine (6) have been prepared and the reactivity of these amino acids, i.e., oxidation of 5 and 6, has been performed at various pH values. Hydrogen peroxide was used as an oxidant and it was treated with 5 and 6 in excess in acidic and basic media. Compound 5, upon oxidation, afforded SeIV and SeVI products. Selenocysteic acid [HO3SeCH2CH(NH2)COOH] 9, a novel SeVI compound, was isolated and characterised by single-crystal X-ray diffraction studies. In contrast, l-tellurocystine, upon oxidation with H2O2, afforded TeII and TeIV products. Zwitterionic organotellurolate(IV), [TeCl3CH2CH(NH3)COOH] 13, was isolated and characterised by NMR and IR spectroscopy, mass spectrometry and elemental analysis. Compound 13 crystallizes in an orthorhombic space group. l-Tellurocystine, when reduced with NaBH4, produced the desired tellurolate intermediate, which was trapped with bromoacetic acid. Furthermore, l- and d-tellurocysteine derivatives, [(RTeCH2CH(NH2)COOH) R=phenyl, substituted phenyl and naphthyl (24–39)] were synthesised and evaluated for their glutathione peroxidase (GPx)-like activities. The results show that l-tellurocysteine derivatives have higher activity than their D-tellurocysteine analogues. DFT calculations for l-tellurocysteine derivatives provided information about the bond lengths and bond angles. This study reveals that the introduction of naphthyl substituents (35–38) leads to twisted conformation of the amino acid derivatives.
- Satheeshkumar, Kandhan,Raju, Saravanan,Singh, Harkesh B.,Butcher, Ray J.
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supporting information
p. 17513 - 17522
(2018/11/23)
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- Syntheses and Structures of Zinc(tmeda)bis(aryltellurolato) and its Facile Chalcogenospecific Ligand Exchange Reactivity
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Anaerobic treatment of Zn(tmeda)Br2, where tmeda denotes N,N,N′,N′-tetramethylethylenediamine, with a solution of Na(TeAr), sodium aryltellurolate, in ethanol in a 1:2 stoichiometry led to the formation of highly air sensitive Zn(tmeda)(TeAr)2 (1–3), while a 1:1 stoichiometry afforded Zn(tmeda)Br(TeAr) (4). Crystallography revealed all complexes to be monomeric with four coordinate central zinc atoms bound to tmeda and two TeAr, or a TeAr and a Br ligand. Upon mixing two symmetrically substituted Zn(tmeda)(TeAr)2 complexes in solution, 125Te NMR revealed a facile ligand exchange providing Zn(tmeda)(TeAr)(TeAr′). In addition, Zn(tmeda)(TeAr)(TeAr′) complexes form on mixing symmetric Zn(tmeda)(TeAr)2 complexes and (TeAr′)2. The lability of the zinc complexes was put to advantage in ligand-substitution reactions wherein treatment of SnCl4 with Zn(tmeda)(TeAr)2 affords Sn(TeAr)4 in excellent yields without the concurrent formation of the redox product (TeAr)2. The apparent lability of the Zn–Te bond prevented the volatilization of 1–3 for their use as chemical vapor deposition precursors for the fabrication of ZnTe thin films. On heating, to volatize the complexes, the complexes decompose to cubic ZnTe and TeAr2 sublimes from the samples. Thermal gravimetric analysis indicates the loss of tmeda followed by the loss of TeAr2.
- Behr, Sandra,Bestvater, Thorsten,Feldmann, Arnold,Kirschbaum, Kristin,Conrad, Olaf,Giolando, Dean M.
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p. 1431 - 1438
(2018/09/25)
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- Copper-catalyzed one-pot tandem synthesis of unsymmetrical diaryl chalcogenides from two different aryl iodides
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Unsymmetrical diaryl chalcogenides were synthesized by a novel one-pot tandem process from two different aryl iodides. A symmetrical diaryl dichalcogenide (ArEEAr, E = Se or Te) was initially obtained by a Cu2O-cataylzed coupling reaction of Ar
- Zhang, Shaozhong,Koe, Adam,Heintz, Christina,Senior, Aunajay,Jin, Jin
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supporting information
p. 260 - 263
(2016/01/12)
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- Iron-catalyzed formation of C-Se and C-Te bonds through cross coupling of aryl halides with Se(0) and Te(0)/nano-Fe3O4@GO
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The formation of C-Se and C-Te bonds is of synthetic and biological importance. Graphene oxide based nano-Fe3O4 (nano-Fe 3O4@GO) is used as a reusable catalyst for the efficient synthesis of diselenides and ditellurides, through cross coupling of Se(0) or Te(0) with aryl iodides. The magnetic heterogeneous catalyst could be easily recovered and reused many times without significant loss of catalytic activity. In addition the superiority of nano-Fe3O4@GO over pristine nano-Fe3O4 is established. Georg Thieme Verlag Stuttgart. New York.
- Kassaee, Mohammadzaman,Motamedi, Elaheh,Movassagh, Barahman,Poursadeghi, Samira
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p. 2337 - 2342
(2013/09/02)
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- Ultrasound-assisted synthesis of symmetrical biaryls by palladium-catalyzed detelluration of 1,2-diarylditellanes
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An ultrasound-assisted synthesis of functionalized symmetrical biaryls with electron-withdrawing or electron-donating substituents is described and illustrated by the palladium-catalyzed detelluration of 1,2-diarylditellanes. This procedure offers easy access to symmetrical biaryls in short reaction time and the products are achieved in good to excellent yields.
- Singh, Fateh V.,Stefani, Hélio A.
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experimental part
p. 863 - 867
(2010/03/24)
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- Tellurium tetrachloride: an improved method of preparation
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An efficient and practical synthesis of tellurium tetrachloride from elemental tellurium and sulfuryl chloride is described.
- Petragnani, Nicola,Mendes, Samuel R.,Silveira, Claudio C.
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p. 2371 - 2372
(2008/09/18)
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- Arylthiols as highly chemoselective and environmentally benign radical reducing agents
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(Chemical Equation Presented) Arylthiols serve as excellent environmentally benign reducing agents for organotellurium, organostibine, and organobismuthine compounds under radical conditions. Both small molecules and macromolecules possessing these heteroatom groups are reduced under moderate thermal conditions to give near quantitative yields in most cases. The reduction shows high chemoselectivity with respect to the heteroatom compounds; the reactivity decreases in the order alkylbismuthines, alkylstibines, and alkyltellurides, while simple alkyl iodides could not be reduced. Alkyltellurides are selectively reduced in the presence of alkyl iodides even when an excess amount of arylthiol is used. Furthermore, alkylstibines are also selectively reduced in the presence of alkyltellurides. Moreover, the reduction conditions are compatible with the presence of a variety of polar functional groups in the substrates, products, and solvents, which are not tolerant under ionic and metal-catalyzed conditions. Carbon-carbon bond formation is possible with use of the carbon-centered radicals that are generated. The results clearly reveal the synthetic utility of arylthiols in organic synthesis.
- Yamago, Shigeru,Matsumoto, Atsushi
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body text
p. 7300 - 7304
(2009/05/09)
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- Facile access to aryltellurium compounds from arylboronic acids
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Arylboronic acids were treated with tellurium tetrachloride to generate substituted aryltellurium trichlorides, which were reduced to the corresponding diaryl ditellurides in good to excellent overall yields. Representative products include diphenyl ditel
- Clark, Aaron R.,Nair, Rashmi,Fronczek, Frank R.,Junk, Thomas
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p. 1387 - 1389
(2007/10/03)
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- O-glycosidation of telluroglycoside by electrochemical oxidation
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The electrochemical oxidation of telluroglycosides in the presence of primary or secondary alcohols results the O-glycosidation with high efficiency. Difference of the oxidation potential is nicely accounted for that of the reactivity of armed-and disarmed-telluroglycosides.
- Yamago, Shigeru,Kokubo, Koji,Yoshida, Jun-Ichi
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p. 111 - 112
(2007/10/03)
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- Sodium telluride in N-methyl-2-pyrrolidone: An efficient telluration system for the synthesis of aromatic tellurides and ditellurides
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Sodium telluride prepared in situ from tellurium and sodium hydride in N-methyl-2-pyrrolidone was found to act as an efficient tellurating agent for nonactivated aromatic iodides, providing a simple route to a variety of diaryl tellurides, alkyl aryl tellurides and diaryl ditellurides.
- Suzuki,Nakamura
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p. 549 - 551
(2007/10/02)
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- Improved preparation of diaryl ditellurides
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Diaryl ditellurides have been synthesized from aryl bromides via lithiation, tellurium insertion, and ferricyanide oxidation of the resulting lithium arenetellurolates.
- Engman, Lars,Persson, Joachim
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- LITHIUM ORGANYL-POLYCHALCOGENOLATES
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Lithium organyl-selenolates, RSeLi or tellurolates, RTeLi insert further equivalents of chalcogens with formation of selenyl-selenolates, RSeSeLi or tellurenyl-tellurolates, RTeTeLi (R=Me, n-Bu, s-Bu, t-Bu, Ph).Mixed anions are only formed if the chalcogen insertion order corresponds with an increase of electronegativity, i.e.: RTeSeLi, RTeSLi, RSeSLi and n-BuTeSeSLi.All species have been characterized by 77-Se and 125-Te NMR-spectroscopy.Tellurenyl-tellurolates and tellurenyl-selenolates are stable at room temperature, selenyl-selenolates and chalcogenyl-thiolatesdisproportionate.The chemical integrity of the chalcogenyl-chalcogenolates was checked by methylation with methyl triflate.The formed organyl-methyl-dichalcogenides exhibit symmetrization equilibria that are also obtained by mixing the symmetric conpounds.Oxidation of tellurenyl-selenolates affords di(organyl-tellurenyl) selenides, (RTe)2Se (R=Me, n-Bu, t-Bu, Ph, p-MeC6H4, 2-thienyl) and (RTe)2Se2 for R=(Me3Si)3C.In solution (RTe)2Se are in equilibrium with R2Te2 and (RTe)2Se2.
- Koellemann, Christoph,Obendorf, Dagmar,Sladky, Fritz
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New syntheses of the telluroxanthene and telluroxanthone are presented. Furthermore, new tellurium-containing esters and 2-tellurium-substituted diphenylmethane derivatives have been prepared, which could not be photo- or thermochemically cyclized to dibe
- Lohner,Praefcke
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p. 167 - 176
(2007/10/02)
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