Efficient copper-free PdCl2(PCy3)2-catalyzed Sonogashira coupling of aryl chlorides with terminal alkynes

[GRAPHICS] Under copper-free conditions and with Cs2CO3 as a base, PdCl2(PCy3)(2) showed high catalytic activity for cross-coupling of electron-rich, electron-neutral, and electron-deficient aryl chlorides with a variety of terminal alkynes in DMSO at 100-120 degrees C affording internal arylated alkynes in good to excellent yields.