One-pot synthesis of 1,4-diarylsubstituted 1,3-diynes from the sequential coupling reactions of aryl iodides and propiolic acid

1,4-Disubstituted 1,3-dialkynes were obtained from the one-pot palladium/copper-catalyzed coupling reactions of aryl iodide and propiolic acid. The optimized catalytic system consisted of 5.0 mol % Pd(PPh3)2Cl2, 10 mol % dppb, 10 mol % CuI, 2.4 equiv of DBU, and 1.2 equiv of K2CO3. The coupling reaction was carried out at 30 °C for 6 h and subsequently at 80 °C for 3 h.