- An alternative approach for the synthesis of aryl-alkyl tellurides: Reaction of aryl iodides with metal alkyltellurolates promoted by CuI
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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.
- Silva, Márcio S.,Comasseto, Jo?o V.
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scheme or table
p. 8763 - 8768
(2011/12/02)
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- Convenient synthesis of unsymmetrical organochalcogenides using organoboronic acids with dichalcogenides via cleavage of the S-S, Se-Se, or Te-Te bond by a copper catalyst
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(Chemical Equation Presented) This article describes the methodology for a copper-catalyzed preparation of numerous monochalcogenides from dichalcogenides with organoboronic acids. Unsymmetrical diorgano-monosulfides, selenides, and tellurides can be synthesized by the coupling of dichalcogenides with aryl- or alkylboronic acids using a copper catalyst in air. The present reaction can take advantage of both organochalcogenide groups on dichalcogenide.
- Taniguchi, Nobukazu
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p. 1241 - 1245
(2007/10/03)
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- Suzuki-Miyaura cross-coupling reactions of aryl tellurides with potassium aryltrifluoroborate salts
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Palladium(0)-catalyzed cross-coupling between potassium aryltrifluoroborate salts and aryl tellurides proceeds readily to afford the desired biaryls in good to excellent yield. The reaction seems to be unaffected by the presence of electron-withdrawing or electron-donating substituents in both the potassium aryltrifluoroborate salts and aryl tellurides partners. Biaryls containing a variety of functional groups can be prepared. A chemoselectivity study was also carried out using aryl tellurides bearing halogen atoms in the same compound. In addition, this new version of the Suzuki-Miyaura cross-coupling reaction was monitored by electrospray ionization mass spectrometry where some reaction intermediates were detected and analyzed.
- Cella, Rodrigo,Cunha, Rodrigo L. O. R.,Reis, Ana E. S.,Pimenta, Daniel C.,Klitzke, Clecio F.,Stefani, Helio A.
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p. 244 - 250
(2007/10/03)
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- A new method for the synthesis of organotellurium compounds by the use of reductive cleavage of the tellurium-tellurium bond with lanthanum metal
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It was confirmed that lanthanum metal is an efficient reagent for the reductive cleavage of the tellurium-tellurium bond of ditelluride. Alkyl phenyl tellurides were prepared by the reaction of diphenyl ditelluride with primary and secondary alkyl halides
- Nishiyama, Yutaka,Okada, Mitsuo,Nishino, Toshiki,Sonoda, Noboru
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p. 341 - 343
(2007/10/03)
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- 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
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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.
- Huang, Xian,Zheng, Wei-Xin
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p. 1365 - 1369
(2007/10/03)
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- Substituent Effects and Stereochemistry in 125Te NMR Spectroscopy. Diorganyltellurium Dihalides and Some Tellurides and Ditellurides
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125Te, 19F and 13C NMR data for 33 compounds containing tellurium substituents are presented.The 125Te chemical shifts in (PhTeCl2)R compounds are between δ=878 and 1023; in corresponding (PhTeF2)R compounds they are 220 to 360 ppm larger.Effects of subst
- Duddeck, Helmut,Biallass, Armin
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p. 303 - 311
(2007/10/02)
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- Reductive cleavage of Se-Se and Te-Te bond by samarium diiodide: Synthesis of selenoesters, telluroesters, unsymmetrical alkylphenyl selenides and tellurides
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The reduction of diaryl diselenides and ditellurides by samarium diiodide led to samarium arylselenolates and samarium aryltellurolates respectively (ArSeSmI2 and ArTeSmI2). These species reacted smoothly with acyl halides and alkyl
- Zhang,Yu,Lin
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p. 189 - 193
(2007/10/02)
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- Transmetallation Between Vinylic Tellurides and Higher Order Cyanocuprates: In Situ Formation of Vinyl Cuprates
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Vinylic tellurides react with higher order dialkylcyanocuprates leading to mixed vinylcyanocuprates with retention of the olefin geometry.The mixed vinylcyanocuprates react with enones giving the 1,4-addition products in good yields.
- Comasseto, J. V.,Berriel, J. N.
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p. 1681 - 1685
(2007/10/02)
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- The use of aminoiminomethanesulfinic acid (thiourea dioxide) under phase transfer conditions for generating organochalcogenate anions. Synthesis of sulfides, selenides and tellurides
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A procedure is described which allows for the in situ synthesis of arylalkyl, diaryl and dialkylchalcogenides under phase transfer conditions starting from the corresponding diorganodichalcogenides.The dichalcogenides are reduced by aminoiminomethanesulfinic acid (thiourea dioxide) in alkaline medium and catalyzed by a quaternary ammonium salt.The reduction proceeds easily for diaryl disulfides and diaryl diselenides at a sodium hydroxide concentration of 13percent; diaryl ditellurides require a 50percent sodium hydroxide solution to give the aryl tellurolate anion.The dialkyl diselenides and dialkyl ditellurides are more difficult to reduce.The intermediate arylthiolates and arylselenolates are quenched by alkyl and activated aryl halides to give the corresponding sulfides and selenides in high yield (77-97percent).The aryltellurolates react with alkyl halides giving the aryl alkyl tellurides in 81-96percent yield.The procedure could not be successfully used for the synthesis of dialkylselenides and dialkyl tellurides; low yields and mixture of products were formed.
- Comasseto, J. V.,Lang, E. S.,Ferreira, J. Tercio B.,Simonelli, F.,Correira, V. R.
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p. 329 - 340
(2007/10/02)
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- A GENERAL PROCEDURE FOR THE SYNTHESIS OF METHYLTHIO-, METHYLSELENO- AND METHYLTELLURO-SUBSTITUTED AROMATIC COMPOUNDS
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A one-pot procedure is described which allows the facile introduction of one or two methylchalcogeno groups into a variety of monobromo or dibromo aromatics.The bromo compounds were converted to their corresponding lithio derivatives by treatment with t-butyllithium in tetrahydrofuran at -78 deg C, and these derivatives were then treated, at ambient temperature with elemental sulfur, selenium, or tellurium.The resulting lithium thiolates, selenolates and tellurolates were finally methylated with methyl iodide to afford good yields (typically 50-80percent) of the various methylchalcogeno-substituted aromatic compounds.The procedure could not be used for the synthesis of ortho-disubstituted compounds, or for the simultaneous introduction of three methylchalcogeno groups.
- Engman, Lars,Hellberg, Jonas S. E.
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p. 357 - 366
(2007/10/02)
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- NUCLEOPHILIC CLEAVAGES OF ESTERS AND ETHERS WITH PHENYLTELLUROTRIMETHYLSILANE
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The title tellurosilane 1 reacted with esters and ethers in the presence of catalytic zinc iodide under very mild conditions, giving the corresponding products with C-telluration and O-silylation via nucleophilic cleavages of the C-O bonds.
- Sasaki, Kazuaki,Aso, Yoshio,Otsubo, Tetsuo,Ogura, Fumio
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p. 453 - 456
(2007/10/02)
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- ALKALINE HYDROLYSIS OF DIARYL DITELLURIDES UNDER PHASE TRANSFER CONDITIONS; SYNTHESIS OF ALKYL ARYL TELLURIDES
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The disproportionation reaction of diaryl ditellurides with sodium hydroxide under phase transfer conditions at room temperature is described for the first time.The phase transfer catalyst used is 2HT-75, a trade name for a mixture of dialkyldimethylammonium chlorides.The intermediates aryl tellurolates react "in situ" with alkyl halides to give the corresponding alkyl aryl tellurides (ArTeR) in 52-72percent yield.The following compounds were prepared: Ar = C6H5, R = CH3(CH2)3CH2,(CH3)2CHCH2CH2, (CH3)2CHCH2, CH3CHBrCH2CH2, CH3(CH2)8CH2, C6H5CH2, ClCH2, C6H5CH2CH2, CH2=CHCH2, C6H5CH=CHCH2, C6H5SeCH2, ; Ar = p-CH3C6H4, R = CH3(CH2)2CH2; Ar = p-CH3OC6H4, R = CH3(CH2)2CH2; Ar = p-C2H5OC6H4, R = CH3(CH2)2CH2; Ar = 2-naphthyl, R = CH3(CH2)2CH2.
- Comasseto, J. V.,Ferreira, J. T. B.,Val, Fontanillas
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p. 261 - 266
(2007/10/02)
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- New Reagents, XXVI. (Phenyltelluro)ethene, 1-Lithio-1-(phenyltelluro)ethene, and (Phenyltelluro)ethyne, Synthesis and Reactions
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(Phenyltelluro)ethene (2a, 78percent) and -ethyne (4, 51percent) were synthesized for the first time.By lithiation with bulky lithium amides (lithium 2,2,6,6-tetramethylpiperidide and lithium dicyclohexylamide) 1-lithio-1-(phenyltelluro)ethene (2b) was obtained from 2a (ca. 50percent yield). 2b reacts with benzaldehyde and chlorotrimethylsilane to give the expected products 2c (88percent) and 2e (80percent), respectively, but no reaction occurred with 1-iodopropane and allyl bromide.
- Kauffmann, Thomas,Ahlers, Holger
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p. 1001 - 1008
(2007/10/02)
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