Recent Advances in the Application of Heterogeneous Nanocatalysts for Sonogashira Coupling Reactions

Sonogashira coupling reactions demonstrates an efficient and facile methodology for C(sp)-C(sp2) bond formations via transition-metal-catalyzed processes and have found applications in a wide variety of areas including medicinal chemistry, agrochemistry, materials, electronics and synthesis of natural products, biologically active molecules, heterocycles, dendrimers and conjugated polymers or nanostructures. In recent years, nanosized heterogeneous catalysts have been widely studied for the above reactions due to thermal stability, reusability and high catalytic activities. In this review, we present an introduction to the subject of carbon-carbon bond formations and recent efforts in the preparation and application of heterogeneous nanocatalysts for Sonogashira coupling reactions. The scope, limitations, and green aspects of the reactions, convenient methods of preparation of heterogeneous nanocatalysts and their characterization have also been highlighted. These include metal nanoparticles, nanoclusters and nanocrystals, bimetallic, trimetallic and core-shell nanoparticles, polymersupported metal nanoparticles, carbon- or graphene-supported metal/metal oxide nanohybrids and metal-organic frameworks Pd catalysts. Numerous examples demonstrated the use of effective supports such as silica, SBA-15, MCM-41, BaO, Smopex®, ZnO, celluloses, montmorillonite, Al²O³, chitosan and natural biomaterials in Sonogashira coupling reactions. This work is dedicated to the 45 years of frankly attempts of Professor Ali Akbar Entezami to the education and development of chemistry in Iran.