Regio‐ and Stereoselective Hydrophosphorylation of Ynamides: A Facile Approach to (<i>Z</i>)‐<i>β</i>‐Phosphor‐Enamides

Abstract

Abstract The first trans ‐selective β ‐hydrophosphorylation of ynamides, which provides a facile approach to ( Z )‐ β ‐phosphor‐enamide derivatives in moderate to excellent yields and with excellent regio‐ and stereoselectivity, is described. This transition‐metal‐free reaction is featured with operationally simple procedure, mild reaction conditions, readily available starting materials, broad substrate scope and good functional‐group tolerance. It is noted that the ( Z )‐ β ‐phosphor (V)‐enamides can be prepared from the oxidation of the corresponding phosphine derivatives or the direct β ‐hydrophosphorylation of ynamides with diphenylphosphine oxide. In addition, cis‐trans isomerization of ( Z )‐ β ‐phosphor (V)‐enamides can be easily realized to furnish the corresponding ( E )‐ β ‐phosphor (V)‐enamides. This advantageous feature enables the preparation of ( Z )‐ β ‐phosphor (V)‐enamides as well as ( E )‐ β ‐phosphor (V)‐enamides from the same starting materials. magnified image