Carbonylation processes and couplings catalyzed by transition metals
have advanced significantly in the production of practical materials and in
commercial applications. Choosing the right ligand is very important in these
reactions. Even though this field has developed a lot in recent years, most
commonly used ligands are phosphine-based compounds that have many
problems such as difficult synthesis, harmful effects, high cost, and the poor
stability under air or moisture conditions. On the other hand, there are many
numerous benefits with N-heterocyclic carbene (NHC) ligands synthesis. These
include lower cost, strong sigma doner, and easy to synthesize. Also, NHCs can
be created from many N-heterocyclic rings, their stability toward air and moisture
and lack of toxicity make them a useful ligand precursor. An overview of using
NHC as donor ligands with palladium to aid the catalyzing of different coupling and carbonylation reactions that can be used in production
of bioactive compounds and other medications
