Mild Pd/Cu-Catalyzed Sila- Sonogashira Coupling of (Hetero)aryl Bromides with (Hetero)arylethynylsilanes under PTC Conditions

The palladium/copper cocatalyzed sila-Sonogashira reaction of (hetero)arylethynysilanes with (hetero) aryl bromides in toluene and water at 40 degrees C under PTC conditions gave the required di(hetero)arylethynes in moderate to high yields. Activated, deactivated and ortho-substituted (hetero) aryl bromides are well tolerated. This protocol also allowed the preparation of symmetrical diarylethynes by double arylation of 1,2-bis(trimethylsilyl)ethyne.