Celebrating 20 Years of SYNLETT - Special Essay: General Procedure for the Palladium-Catalyzed Selective Hydrophosphorylation of Alkynes

A novel catalytic system has been developed to accomplish the hydrophosphorylation of terminal and internal alkynes with high isolated yields (up to 96%) and excellent regio- and stereo-selectivity (>99:1). The key factor was to apply a low-ligated palladium/triphenylphosphane (1:2) catalytic system in the presence of a catalytic amount of trifluoroacetic acid. The catalytic system so developed has been applied successfully to permit the formation of diverse alkenylphosphonates utilizing a variety of available H-phosphonates and alkynes.