A general method of synthesis of functionalized Z-vinylic tellurides starting from β-dicarbonyl compounds
作者:Rafael E Barrientos-Astigarraga、Priscila Castelani、Celso Y Sumida、Julio Zukerman-Schpector、João V Comasseto
DOI:10.1016/s0040-4020(01)01204-2
日期:2002.2
Z-Vinylic tellurides are prepared by stereoselective vinylic substitution on Z/E mixtures of enolphosphates, acetates, tosylates and triflates by organotellurolates. The reaction is sensitive to the nature of the organotellurolate; the aromatic derivatives react slower than the aliphatic ones. The reaction time is not influenced by the nature of the leaving group.
Vinylictellurides are precursors of important highly reactive vinylic organometallics (e.g. vinyl Li and Cu species). Herein we report that tri- and tetrasubstituted functionalized vinylictellurides can be prepared from enolphosphates through a vinylic substitution by lithium butyltellurolate. Starting from mixtures of Z- and E-enolphosphates, only the Z-vinylic telluride is formed.