Synthesis of symmetrical diarylalkyne from palladium-catalyzed decarboxylative couplings of propiolic acid and aryl bromides under water

Symmetric diarylalkynes were obtained from the decarboxylative coupling reactions of aryl bromides and propiolic acid in water solvent condition. In the presence of phase transfer surfactant C18H37N(CH3)3Cl, the catalytic system of both Pd(PPh3)2Cl2/dppb and Pd(TPPMS)2Cl2/TPPMS afforded the desired coupled products in good yields.