75250-42-9Relevant academic research and scientific papers
A new method for the synthesis of organotellurium compounds by the use of reductive cleavage of the tellurium-tellurium bond with lanthanum metal
Nishiyama, Yutaka,Okada, Mitsuo,Nishino, Toshiki,Sonoda, Noboru
, p. 341 - 343 (2007/10/03)
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
One-pot synthetic method of unsymmetrical diorganyl selenides: Reaction of diphenyl diselenide with alkyl halides in the presence of lanthanum metal
Nishino, Toshiki,Okada, Mitsuo,Kuroki, Takamasa,Watanabe, Toshihisa,Nishiyama, Yutaka,Sonoda, Noboru
, p. 8696 - 8698 (2007/10/03)
A convenient synthetic method of unsymmetrical selenides has been developed. When diphenyl diselenide was allowed to react with two equimolar amounts of primary alkyl iodides and bromides in the presence of an equimolar amount of lanthanum metal, alkyl ph
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.
The use of aminoiminomethanesulfinic acid (thiourea dioxide) under phase transfer conditions for generating organochalcogenate anions. Synthesis of sulfides, selenides and tellurides
Comasseto, J. V.,Lang, E. S.,Ferreira, J. Tercio B.,Simonelli, F.,Correira, V. R.
, p. 329 - 340 (2007/10/02)
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.
Oxidation of Alkyl Phenyl Selenides, Tellurides, and Telluroxides with meta-Chloroperbenzoic Acid for a Facile and Novel Transformation of C-Se and C-Te Bonds to C-O Bonds
Uemura, Sakae,Fukuzawa, Shin-ichi
, p. 471 - 480 (2007/10/02)
In sharp contrast to the well-known selenoxide elimination leading to olefins, the treatment of alkyl phenyl selenides (PhSeR) with an excess of meta-chloroperbenzoic acid (MCPBA; 2-5 equiv. to a selenide) in alcohol at room temperature affords the corresponding dialkyl ethers by the substitution of a phenylselenium (PhSe) moiety with an alkoxy group.A similar reaction proceeds by using alkyl phenyl tellurides (PhTeR) and telluroxides , a facile substitution of PhTe or PhTe(O) moiety by an alkoxy group being observed.Methanol is the most appropriate solvent for these oxidations and alkyl methyl ethers are formed in excellent yields.The reaction is accompanied by phenyl migration when applied to some selenides, tellurides, and telluroxides having a phenyl group at a vicinal position to the PhSe, PhTe, or PhTe(O) moiety.Application to the methoxyselenation and methoxytelluration products of cyclohexene and cycloheptene results in a ring-contraction to afford the dimethyl acetals of cyclopentane- and cyclohexane-carbaldehyde, respectively.In case of an allylic phenyl selenide, a sigmatropic rearrangement giving a rearranged allylic alcohol occurs in much preference to the substitution by the methoxy group.Other oxidizing agents than MCPBA such as NaIO4, H2O2, t-BuOOH, and ozone are generally ineffective under similar conditions.It is proposed that the reaction mainly takes place as follows.Alkyl phenyl selenone, alkyl phenyl tellurone, or the MCPBA addition product to them is formed as a reactive intermediate in which an alkyl C-Se or alkyl C-Te bond fission occurs heterolytically by a nucleophilic attack of alcohol, sometimes accompanied by a 1,2-shift of the β-substituent, i.e., phenyl migration and ring-contraction.
New Aspects of the Telluroxide Elimination. A Facile Elimination of sec-Alkyl Phenyl Telluroxide Leading to Olefins, Allylic Alcohols, and Allylic Ethers
Uemura, Sakae,Fukuzawa, Shin-ichi
, p. 2748 - 2752 (2007/10/02)
The utility of the telluroxide for olefin synthesis, a reaction which previously appeared to be of little value, is described.Treatment of sec-alkylphenyltellurium dibromides, except for the cyclohexyl system, with aqueous NaOH at room temperature affords olefins, allylic alcohols, and/or allylic ethers in high yields presumably via the formation of sec-alkyl phenyl telluroxides and their facile telluroxide elimination.As to the formation of linear olefins, more preference for elimination toward the less substituted carbon was observed than the selenoxide and sulfoxide eliminations.In the cyclododecyl case only trans-cyclododecene was formed as an olefin component in a sharp contrast to the selenoxide elimination that affords a 1:1 mixture of cis and trans isomers.On the contrary, in the n-alkyl and cyclohexyl cases the corresponding telluroxides are stable compounds that afford similar elimination products including vinylic ethers only by neat pyrolysis at temperatures above 200 deg C.
OLEFIN SYNTHESIS BY REACTION OF ALKYL PHENYL TELLURIDES WITH CHLORAMINE-T
Otsubo, Tetsuo,Ogura, Fumio,Yamaguchi, Hachiro,Higuchi, Hiroyuki,Sakata, Yoshiteru,Misumi, Soichi
, p. 447 - 448 (2007/10/02)
Alkyl phenyl tellurides reacted with chloramine-T in refluxing tetrahydrofuran to give olefins in high yields.
Organic Tellurium and Selenium Chemistry. Reduction of Tellurides, Selenides, and Selenoacetals with Triphenyltin Hydride
Clive, Derrick L. J.,Chittattu, Gim J.,Farina, Vittorio,Kiel, William A.,Menchen, Steven M.,et al.
, p. 4438 - 4447 (2007/10/02)
Preparative and mechanistic details are described for the conversion of selenides into hydrocarbons RH> by heating with triphenyltin hydride at about 120 deg C.The process has been extended to selenoacetals in a form that constitutes a reduction methods for carbonyl compounds RR'C(SePh)2 -> RR'CH2>.Selective reduction of selenoacetals in the presence of thioacetals is possible.Cold-labeled species can be prepared by using triphenyltin deuteride.Tellurides are available easily without problems arising from exposure to air provided that the work is done in a photographic darkroom equipped with a red safety light.These tellurides, as well as the corresponding dichlorides , are reduced under very mild conditions (25-80 deg C) by triphenyltin hydride.The selenium- and tellurium-based chemistry has been used for the unusual process of reducing an epoxide in the presence of a ketone carbonyl.
