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 5.0mol% Pd(PPh3)2Cl2, 10mol% dppb, 10mol% CuI, 2.4equiv of DBU, and 1.2equiv of K2CO3. The coupling reaction was carried out at 30°C for 6h and subsequently at 80°C for 3h.