From organyl tellurols or tellurolates and terminal acetylenes

2 From organyl tellurols or tellurolates and terminal acetylenes 

Alkyl- and aryltellurols generated in situ by the well-established reduction of ditellurides with NaBH /EtOH add to terminal acetylenes, giving (Z)-vinylic tellurides.  

The addition of the tellurium occurs exclusively at the terminal carbon of phenylacety-lene, whereas a minor amount (11-28%) of the 2,2-disubstituted adduct (RTeR C=CH2) is formed in addition to alkylacetylenes. 

The above-described hydrotelluration have been successfully applied to conjugated enines and dimes, functionalized alkynes and diines. providing a useful method for the synthesis of organoteUuro 1,3-butadienes, organotelluro 1,3-enines and functionalized vinylic tellurides with the Z configuration at the newly formed C=C bond. 

Noteworthy is that by treating tellurothioalkene with n-BuLi, the phenylthio group remains untouched, showing the greater reactivity of vinyltelUuride towards vinylsulphide (eq. (4)). 

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