Ionic Liquids and the Heck Coupling Reaction: An Update

In this review update we provide a critical analysis of recent results concerning the use of ionic liquids (ILs) as viable, effective, and environmental friendly media for the Heck reactions (HR). The examples selected illustrate the multifaceted action of ILs as nanoparticles stabilizers, promoters of ligand-assisted HR, promoters of phosphine-free HR, solvent for the Heck-Matsuda reactions employing arenediazonium salts, in the dehydrative Heck olefination, and as charged-tagged pre-catalysts. These selected reports aim at demonstrating the scope and the impact of Ils on new discoveries, as well as to illustrate the new opportunities and challenges they offer for those interested in catalysis and organic synthesis in general.