Coordinated carbene and nitrene species were suggested as the key intermediates in hydrogen-transfer reduction of multiple bonds and reduction of nitroaromatics by CO catalysed with giant Pd-561 clusters as well as in the reaction of Pd (I) carbonylacetate cluster with nitrosobenzene. In the last reaction, a palladium complex with phenyl-o-nitrosophenylamide was obtained whose structure gives evidence for the intermediacy of nitrene ligands in Pd-catalysed reactions.