Air-stable CpPd(NHC)Cl (NHC = N-heterocyclic carbene) complexes as highly active precatalysts for Kumada–Tamao–Corriu coupling of aryl and heteroaryl chlorides

A very straightforward one-pot method has been developed for preparation of air-stable CpPd(NHC)Cl complexes 1a–d. This new class of well-defined NHC–Pd complexes exhibits high catalytic activity in Kumada–Tamao–Corriu cross-coupling reaction involving various aryl and heteroaryl chlorides. Notably, the less sterically encumbered NHC ligand around Pd centre showed higher catalytic activity.