First example of the <Emphasis Type="Italic">anti</Emphasis>-Markownikoff addition of tellurium tetrachloride to terminal acetylene,trimethyl ethynyl silane

(μ₂-Oxo)-bisdichloro(Z-2-chloro-1-trimethylsilylethenyl)tellurium(IV)] (III) was prepared by electrophilic addition of TeCl₄ to trimethylethynylsilane in CHCl₃ at room temperature. The reaction is the first example of the anti-Markownikoff type addition of TeCl₄ to terminal acetylenes affording as an intermediate the 1:1 adduct Z-1-(trimethylsilyl)-2-chlorovinyl]tellurium trichloride (II). The latter is converted into III by a sequence of successive reactions of hydrolysis and dehydration. The structure of compound III was proved by the of multinuclear (¹H, ¹³C, ²⁹Si, ¹²⁵Te) NMR spectroscopy and XRD analysis. Compound III is the first example of structurally characterized C-TeCl₂-O fragment.