An Amine‐, Copper‐ and Phosphine‐Free Sonogashira Coupling Reaction Catalyzed by Immobilization of Palladium in Organic–Inorganic Hybrid Materials

An immobilization of palladium in organic‐inorganic hybrid materials‐catalyzed Sonogashira coupling reaction has been described. Terminal alkynes reacted with aryl iodides and aryl bromides only in the presence of a 3‐(2‐aminoethylamino)propyl‐functionalized, silica gel‐immobilized palladium catalyst under amine‐, copper‐ and phosphine‐free reaction conditions. The reaction generates the corresponding cross‐coupling products in excellent yields. Furthermore, the silica‐supported palladium can be recovered and recycled by a simple filtration of the reaction solution and used for 30 consecutive trials without any decreases in activity.