An efficient palladium-catalyzed homocoupling of terminal alkynes using DABCO as the ligand has been developed. In the presence of Pd(OAc)2(2 mol% ) ,DABCO (4 mol% ), CuⅠ (2 mol% ) ,NaOAc (3 mmol), MeCN (5 mL) and air, a variety of terminal alkynes (1 mmol)undergo homocoupling reaction smoothly to afford the corresponding diynes in mode...