“…These catalysts work as oxidants. Plentiful N-heterocyclic carbene catalysts based on various metal complexes, such as Pd, 27,28 Pt, 29 Rh, 30 Ir, 31 Ru, 32 Co, 33 Fe, 34 Ni, 35 Cu, 36 Ag, 37 and Au, 38 have been used for the C–H bond functionalization reaction. Although palladium NHC complexes have strong electron donor and flexible steric bulkiness properties compared to phosphine and N-donor ligands, they also have hydrolytic instability, due to which their application in cross-coupling reactions has not been prominent.…”