Copper-catalyzed addition of H-phosphine oxides to alkynes forming alkenylphosphine oxides

We have developed efficient copper-catalyzed additions of P(O)H compounds to alkynes, and the reactions provided the regio- and stereoselective E-alkenylphosphine oxides under catalysis of the commercially available and inexpensive copper catalyst system CuI/ethylenediamine. This finding is the first example of copper-catalyzed hydrophosphinylation of alkynes to synthesize alkenylphosphine oxides.