Switchable iridium hydride catalysts for controlling selectivity of alcohol oxidation

Abstract

Novel pyridyl-triazolylidene iridium(III) hydride complexes have been synthesized through modification of the analogous iridium chloride complexes. The dehydration of alcohols was used to probe the catalytic potential of the iridium chloride compounds and the influence of the electronic modification on the pyridyl-triazolylidene ligand scaffolds. The incorporation of electron donor substituents on the triazolylidene heterocycle considerably enhanced the catalytic activity of the coordinated iridium center towards the catalytic dehydration of alcohols. Moreover, the iridium hydride compounds are switchable catalysts that perform either alcohol dehydration or dehydrogenation. Their selectivity was predictably triggered by the presence or absence of HPF6 in the catalytic reaction.