872-89-9Relevant articles and documents
Photostimulated telluromethylation
Junk, Thomas,Fronczek, Frank R.
, p. 4361 - 4362 (1996)
Photostimulated reaction of bromo- and iodoarenes with potassium tellurocyanate in dimethylsulfoxide produces aryl methyl tellurides in moderate yields. This method offers facile access to aryltellurium compounds which are difficult to prepare by other methods.
Synthesis and Reactivity Studies of a Series of Nickel(II) Arylchalcogenolates
Cordeiro, Lauren L.,Dmitrenko, Olga,Yap, Glenn P. A.,Riordan, Charles G.
, p. 6327 - 6338 (2021/05/06)
Two series of high-spin nickel complexes, [TpPh,Me]Ni(EAr) (E = O, Se, Te; Ar = C6H5) and [TpPh,Me]Ni(SeC6H4-4-X) (X = H, Cl, Me, OMe), were prepared by metathetical reaction of the nickel(II) halide precursor with sodium salts of the corresponding chalcogen, NaEAr. X-ray crystallographic characterization and spectroscopic studies have established the geometric and electronic structures of these complexes. The observed spectroscopic and structural characteristics reveal distinct trends in accordance with the variation of the identity of the arylchalcogenolate and para substituent. Reaction of the [TpPh,Me]Ni(EAr) complexes with methyl iodide proceeded readily, producing the corresponding methylarylchalcogen and [TpPh,Me]NiI. A kinetic and computational analysis of the reaction of [TpPh,Me]Ni(SeC6H5) with MeI supports that the electrophilic alkylation reactions occur via an associative mechanism via a classical SN2 transition state.
An alternative approach for the synthesis of aryl-alkyl tellurides: Reaction of aryl iodides with metal alkyltellurolates promoted by CuI
Silva, Márcio S.,Comasseto, Jo?o V.
supporting information; experimental part, p. 8763 - 8768 (2011/12/02)
Aryl iodides react with metal organotellurolates in tetrahydrofuran/ dimethylformamide in the presence of CuI (5 mol %) or CuI (5 mol %) and 1,10-phenanthroline (10 mol %) to afford the corresponding aryl-alkyl tellurides in good yields.
FeCl3-Diorganyl dichalcogenides promoted cyclization of 2-alkynylanisoles to 3-chalcogen benzo[ b ]furans
Gay, Rafaela M.,Manarin, Flavia,Schneider, Caroline C.,Barancelli, Daniela A.,Costa, Michael D.,Zeni, Gilson
supporting information; experimental part, p. 5701 - 5706 (2010/10/03)
A general synthesis of 3-chalcogen benzo[b]furans from the readily available 2-alkynylanisoles, via FeCl3/diorganyl dichalcogenides intramolecular cyclization, has been developed. Aryl and alkyl groups directly bonded to the chalcogen atom were used as cycling agents. The results revealed that the reaction significantly depends on the electronic effects of substituents in the aromatic ring bonded to the selenium atom of the diselenide species. We observed that the pathway of reaction was not sensitive to the nature of substituents in the aromatic ring of anisole since both the electron-donating and the electron-withdrawing groups delivered the products in similar yields. In addition, the obtained heterocycles were readily transformed to more complex products by using a chalcogen/lithium exchange reaction with n-BuLi followed by trapping of the lithium intermediate with aldehydes, furnishing the desired secondary alcohols in good yields.
Deoxygenation of sulfoxides, selenoxides, telluroxides, sulfones, selenones and tellurones with Mg-MeOH
Khurana, Jitender M.,Sharma, Vandana,Chacko, Silvi A.
, p. 966 - 969 (2007/10/03)
The deoxygenation of a variety of sulfoxides, selenoxides, telluroxides, sulfones, selenones and tellurones has been reported with Mg-MeOH at room temperature in nearly quantitative yields. The deoxygenation is proposed to proceed by SET from Mg to the substrate.
Aqueous phase one-electron reduction of sulfonium, selenonium and telluronium salts
Eriksson, Per,Engman, Lars,Lind, Johan,Merenyi, Gabor
, p. 701 - 705 (2007/10/03)
Triorganylsulfonium, -selenonium and -telluronium salts were reduced by carbon dioxide radical anions/solvated electrons produced in aqueous solution by radiolysis. The radical expulsion accompanying reduction occurred with the expected leaving group propensities (benzyl > secondary alkyl > primary alkyl > methyl > phenyl), although greater than expected loss of the phenyl group was often observed. Diorganyl chalcogenides formed in the reductions were conveniently isolated by extraction with an organic solvent. Product yields based on the amount of reducing radicals obtained from the γ-source were often higher than stoichiometric (up to 1800 %) in the reduction of selenonium and telluronium compounds; it is likely that this result can be accounted for in terms of a chain reaction with carbon-centred radicals/formate serving as the chain transfer agent. The product distribution was essentially independent of the reducing species for diphenyl alkyl telluronium salts, whereas significant variations were seen for some of the corresponding selenonium salts. This would suggest the intermediacy of telluranyl radicals in the one-electron reduction of telluronium salts. However, pulse radiolysis experiments indicated that the lifetimes of such a species (the triphenyltelluranyl radical) would have to be less than 1 μs. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
A new path for the reductive cleavage of te-te bond by the system of Cp2TiCl2/i-BuMgBr and its utility in synthesis of unsymmetrical tellurides
Huang, Xian,Zheng, Wei-Xin
, p. 1365 - 1369 (2007/10/03)
The cleavage reduction of ditellurides by Cp2TiCl2/i- BuMgBr lead to nucleophilic tellurides [Cp2TiTeAr]. This species reacts with aliphatic bromides to give unsymmetrical tellurides in good yield.
Reversibility in free-radical reactions of aryltellurides with tributylstannyl, tributylgermyl and tris(trimethylsilyl)silyl radicals
Schiesser, Carl H.,Skidmore, Melissa A.
, p. 145 - 157 (2007/10/03)
1H, 13C, 29Si, 77Se, 119Sn and 125Te NMR spectroscopies reveal that methyl, primary and secondary alkyl radicals, generated through the reaction of aryltelluroalkanes (4-9) with tributyltin hydride, tributylgermanium hydride or tris(trimethylsilyl)silane) under standard radical conditions (benzene, AIBN) are capable of displacing tributylstannyl, tributylgermyl and tris(trimethylsilyl)silyl radicals from aryltellurotributylstannanes (1, 2), aryltellurotributylgermanes (10, 11) and aryltellurotris(trimethylsilyl)silanes (13, 14) respectively. These observations are in agreement with high-level ab initio molecular orbital studies. Calculations using a (valence) double-ζ pseudopotential basis set supplemented with polarization functions and with the inclusion of electron correlation (MP2/DZP) predict energy barriers for the displacement of stannyl (SnH3), germyl (GeH3) and trisilylsilyl ((H3Si)3)Si) radicals by methyl, ethyl and iso-propyl radicals to lie between 22 and 39 kJ mol-1, with reverse barriers of between 12 and 40 kJ mol-1. Consequently, the use of aryltellurides as alkyl radical precursors together with (standard) chain-carrying reagents such as tributyltin hydride, tributylgermanium hydride and tris(trimethylsilyl)silane may be complicated with equilibria which may result in diminished reaction yields.
Thermal reactions of organyl chalcogenides with α,β-unsaturated aldehydes
Deryagina, E. N.,Korchevin, N. A.,Shilkina, T. A.,Sukhomazova, E. N.,Levanova, E. P.
, p. 447 - 450 (2007/10/03)
Thermalgas-phase reactions of acrolein, cinnamaldehyde, and benzaldehyde with diorganyl chalcogenides and diorganyl dichalcogenides were studied.Acrolein does not react with chalcogenides at 300-600 deg C but completely decomposes under reaction conditions.At 600-650 deg C, cinnamaldehyde reacts only with diorganyl selenides and diselenides to give benzoselenophene.Its highest yield (53percent) is achieved in the reaction with dimethyl diselenide at 630 deg C and at an equimolar ratio of the reactants.The gas-phase reactions of benzaldehyde at 400-500 deg C afford chalcogen-containing derivatives of several types, among which thioanisole and its selenium or tellurium analogs predominate.The mechanisms of the above reactions were discussed in terms of homolytic substitution of the formyl group at unsaturated carbon atoms by chalcogenyl radicals. - Keywords: gas-phase reactions; cinnamaldehyde; benzaldehyde; chalcogenyl radicals; benzoselenophene, selenoanisole, telluroanisole.
(Aryltelluro)formates as precursors of alkyl radicals: Thermolysis and photolysis of primary and secondary alkyl (aryltelluro)formates
Lucas, Mathew A.,Schiesser, Carl H.
, p. 5754 - 5761 (2007/10/03)
Alkyl (aryltelluro)formates are effective precursors of oxyacyl, methyl, and primary and secondary alkyl radicals. At room temperature, irradiation of a benzene solution of methyl (aryltelluro)-formates 10-12, 2-methylpropyl (aryltelluro)formates 14 and 15, octyl (phenyltelluro)formate (17), cyclohexyl (aryltelluro)formates 19 and 20, 3β-cholestanyl (aryltelluro)formates 22 and 23, cholesteryl (phenyltelluro)formate (24) and benzyl (phenyltelluro)formate (27) with a 250-W low-pressure mercury lamp leads to the formation of oxyacyl radicals (34), which can be trapped by diphenyl diselenide to give the corresponding alkyl (phenylseleno)formates 13, 16, 18, 21, 24, 26, and 28 with excellent overall conversions. Thermolysis of these telluroformates at 160 °C in the dark leads to the formation of methyl and primary and secondary alkyl aryl tellurides 36-43 in excellent yields. Presumably, these transformations involve oxyacyl radicals, which undergo subsequent decarboxylation at the elevated temperature to afford alkyl radicals, which become involved in further radical chemistry. When 1-(benzylseleno)-5-hexyl (phenyltelluro)formate (44) was thermolysed under these conditions, 2-methylselenane (45) was observed as the sole selenium-containing product, demonstrating the synthetic utility of (aryltelluro)formates as alkyl radical precursors.
