Stereoselective formation of 1,2-diiodoalkenes and their application in the stereoselective synthesis of highly functionalised alkenes via Suzuki and Stille coupling reactions

Treatment of an alkyne with iodine monochloride and sodium iodide at room temperature results in the formation of the thermodynamic (E)-diiodoalkene. The corresponding (Z)-diiodoalkene can also be produced, by treatment of the alkyne with iodine monochloride at -78 degrees C in the presence of tetraethylammonium iodide. Such 1,2-diiodoalkenes are useful for the synthesis of more functionalised alkenes by using either Stille or Suzuki cross-coupling protocols.