Copper-Catalyzed Decarboxylative C–P Cross-Coupling of Alkynyl Acids with H-Phosphine Oxides: A Facile and Selective Synthesis of (E)-1-Alkenylphosphine Oxides

A novel and efficient copper-catalyzed decarboxylative cross-coupling of alkynyl acids for the stereoselective synthesis of E-alkenylphosphine oxides has been developed. In the presence of 10 mol % of CuCl without added ligand, base, and additive, various alkynyl acids reacted with H-phosphine oxides to afford E-alkenylphosphine oxides with operational simplicity, broad substrate scope, and the stereoselectivity for E-isomers.