From diaryl ditellurides by extrusion of a tellurium atom

6 From diaryl ditellurides by extrusion of a tellurium atom 

Diaryl ditellurides are relatively thermolabile compounds and eliminate one tellurium atom by heating at 300°C. ° In the presence of copper metal, however, the extrusion of tellurium is achieved during reflux with toluene or dioxane.  

Ar = p-MeCgl-l4, /n-MeOCel-14, p-FCgl-l4, /n-BrCgH4, p-N02CgH4, p-Me3SiCgH4, 4-biphenyl, [2-(2-quinolylphenyl)] 

6-trimethylphenyl) telluride (typical procedure). A solution of bis(2,4, 6-trimethylphenyl) ditelluride (4.94 g, 10 mmol) in toluene (150 mL) is refluxed in the presence of electrolytic Cu (1.40 g, 22 mmol) for 12 h. The mixture is filtered and the filtrate evaporated to give the pure telluride (m.p. 123-125°C). 

On the basis that bis-organyl tellurides undergo Te/Li exchange by treatment with an organolithium reagent, if a thermodynamically more stable organolithium moiety is released,bis-(phenylethynyl) telluride has been employed as starting material for the synthesis of diaryl tellurides.  

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