Stereoselective Synthesis of Internal Alkenyl Iodides from Alkynes via Addition of Hydrogen Iodide Generatedin situfrom a Chlorotrimethylsilane/Sodium Iodide/Water System

Hydrogen iodide, cleanly generated in situ from chlorotrimethylsilane/sodium iodide/water in acetonitrile under mild conditions, was found to be an attractive reagent for the synthesis of alkenyl iodides. The hydrogen iodide thus generated added to both terminal and internal alkynes with complete cis-selectivity in a Markovnikov fashion to give the corresponding (E)-alkenyl iodides in fair to good yield.