Ruthenium(II) complexes bearing N-heterocyclic carbene ligands with wingtip groups and their catalytic activity in the transfer hydrogenation of ketones

•Silver and ruthenium-N-heterocyclic carbene complexes were synthesized and characterized.•The silver complexes were used as carbene-transfer agents to synthesize ruthenium(II) complexes.•These ruthenium complexes were tested as catalysts in the transfer hydrogenation of ketones.