Stereoselective synthesis of E-2-halovinyl tellanes, ditellanes and selenides based on tellurium tetrahalides, selenium dihalides and internal alkynes.

The reactions of selenium dihalides, tellurium tetrachloride and tetrabromide with 3-hexyne and 4-octyne proceed in a stereoselective manner as anti-addition to afford products of E-stereochemistry. First examples of bis-adduct synthesis from tellurium tetrachloride and disubstituted acetylenes as well as of the addition of tellurium tetrabromide to disubstituted acetylenes were described. Reaction conditions for efficient stereoselective synthesis of E-2-halovinyl tellanes, ditellanes and selenides were developed. [ABSTRACT FROM AUTHOR]