Mild Stereoselective Hydrohalogenation Leading to (Z)-Halopropenamides at Room Temperature

Hydroiodination of 2-propynamides leading stereoselectively to (Z)-iodopropenamides was achieved under mild conditions at room temperature by the combined use of zinc iodide and tert-butyl iodide. Similarly, the use of zinc bromide in the presence of tert-butyl bromide enabled the synthesis of (Z)-bromopropenamides. (Z)-Halopropenoic esters were also prepared in high yields.