A naphthalene-based heterobimetallic triazolylidene Ir/Pd complex: regioselective to regiospecific C-H activation, tandem catalysis and a copper-free Sonogashira reaction.

Heterobimetallic complexes featuring mesoionic carbene (MIC) donor ligands are gaining enormous popularity in tandem catalysis owing to the combined action of two different metal centers during catalysis. A rare version of the heterobimetallic Pd/Ir complex possessing a cyclometalated mesoionic carbene (MIC) ligand is presented along with the analogous homodinuclear Pd complex. A sterically controlled regiospecific cyclometalation towards the formation of a six-membered ring complex over a five-membered ring complex has been performed using a naphthalene-based bis-MIC ligand platform.