Styryl tellurides

Styryl tellurides are also detellurated on treatment with lithium chloropalladate (2 equiv), giving stereoisomeric mixtures of the homocoupled 1,3-butadienes. 

Method a. (ji-Styryl) phenyl telluride. To a solution of methyltriphenylphosphonium iodide (0.405 g, 1 mmol) in dry THF (4 mL) at room temperature was added dropwise n-BuLi (2 mmol). After stirring at room temperature for 20 min the solution was cooled to -78°C and a solution of PhTeBr (0.28 g, 1 mmol in 2 mL THF) was added, followed by benzaldehyde (0.16 g, 1.5 mmol). The temperature was raised to room temperature and stirred for 3 h. The solvent was removed under vacuum and the residue incorporated on Si02 and purified by flash column chromatography (Si02/hexane) giving an oil. Yield 0.185 g (60%). E/Z=2. 

On treatment with Pd(II) acetate, distyryl telluride fnmishes styryl acetate ... 

Vinylic and divinylic tellnrides react with alkenes in MeOH in the presence of a combination of catalytic amounts of PdCl2 together with AgOAc and EtjN to afford the corresponding vinyl-substituted alkenes The products result respectively from the coupling of the styryl and phenyl moieties of the starting telluride with retention of its double-bond stereochemistry. 

Method a. (fl-Styryl) phenyl telluride. To a solution of methyltriphenylphosphonium iodide (0.405 g, 1 mmol) in dry THF (4 mL) at room temperature was added dropwise n-BuLi (2 mmol). After stirring at room temperature for 20 min the solution was cooled to... 

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