The sonogashira reaction:: A booming methodology in synthetic organic chemistry

An overview is given of the developments in the Sonogashira cross-coupling reaction as well as applications of the methodology since 2003. Topics discussed include mechanistic considerations, catalysts and reaction conditions and applications. Under the catalysts and reaction conditions topic, emphasis is on palladium-phosphorus complexes, palladium-nitrogen complexes, palladium-P,N- and palladium-P,O complexes, N-heterocyclic carbene (NHC) palladium complexes, palladacycle catalysts, ligand-free palladium catalysts, palladium nanoparticles as catalysts and transition-metal-free reactions. As for applications, discussion focuses on (1) alkynylation of arenes and heterocycles and (2) synthesis of enynes and enediynes, ynones, carbocyclic systems, heterocyclic systems, natural products, electornic and electrooptical molecules and molecules for nanostructures.