Efficient Copper-Free PdCl₂(PCy₃)₂-Catalyzed Sonogashira Coupling of Aryl Chlorides with Terminal Alkynes

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 °C affording internal arylated alkynes in good to excellent yields.