Carbon Ditelluride

A tellurium analogue of carbon disulphide has not been isolated. A product described as carbon ditelluride 1 has been shown to consist of the sulphidotelluride and its decomposition products. 

Carbon ditelluride has not yet been prepared. Attempts to prepare this compound from carbon tetrachloride and hydrogen telluride, carbon tetrabromide or tetraiodide and silver telluride, carbon and tellurium2, or dichloromethane and tellurium3 were unsuccessful. The claim of the preparation of carbon ditelluride by sputtering tellurium from a tellurium/graphite electrode in a DC-arc under carbon disulfide4 was withdrawn5. 

It has, however, also been reported that the reaction of aryl ditellurides with Ni°, Pd°, and Pt° may result in the cleavage of the carbon-chalcogen bond. The oxidative addition of... 

Common esters such as alkyl and benzyl carboxylates are easily dealkylated by sodium hydrogen telluride, sodium telluride and sodium ditelluride in DMF. In accordance with a typical S 2 displacement at the aUcoxy group carbon, methyl, ethyl and benzyl esters react smoothly. The nucleophilicity of the reagents is enhanced by the polar aprotic solvent, and the reactivity decreases with higher alkoxy chains due to steric hindrance (e.g. 

At present there are few examples of isolable, well-characterized sources of tellurolate anions (RTe-).1 Although insertion of elemental tellurium into reactive metal-carbon bonds has been known for many years, the resulting solutions contain a mixture of compounds in addition to the RTe- species of interest.2 Alkali metal phenyltellurolate salts, prepared via metal reduction of diphenyl ditelluride in liquid ammonia, were first isolated by Klar and co-workers.3 More recently Lange and Du Mont reported the synthesis of the bulky aryl tellurolate (THF)3Li[Te(2,4,6-f-Bu3C6H2)],4 and Sladky described the in situ formation of a bulky alkyl tellurolate via reaction of tellurium with LiC(SiMe3)3.5 Acidification of aryltellurolate anions affords thermally sensitive tellurols (RTeH) that are stable only below room temperature.6... 

Other Elements - Irradiation ((>300 nm) of the allene (366) in the presence of diphenyl diselenide affords a high yield of the adduct (367) as an El Z mixture (28 72). Diphenyl disulfide affords a complex mixture of products with the same allene while diphenyl ditelluride does not react. The difference between the sulfide and the selenide is due to the lower ability of diphenyl disulfide to react with carbon radicals. When a mixed system is used [(PhS)2 (PhSe)2 as a 1 1 mixture] mixed addition occurs. Thus with the allene (366) an almost quantitative yield of (368) is produced and other allenes (369) are also reactive imder these conditions, affording (370). The use of diphenyl selenide as a catalyst for the photochemical isomerism of some carotenoids has been described. ... 

The addition is regiospecific, the tellurium moiety bonding to the less hindered carbon atom, and stereospecific as demonstrated by the anti addition to cyeloalkenes. By the first procedure the trichloride is reduced without isolation to the corresponding ditelluride (see Section 3.2.3.2). 

---