Two step activation of Ru‐PN3P pincer catalysts for CO2 hydrogenation

Activation of homogeneous catalysts is an important step in ensuring efficient operation of any catalytic system as a whole. For the majority of pincer catalysts, the activation step leans heavily on the metal ligand cooperative chemistry that allows these complexes to react with small molecule substrates and engage in catalytic transformations. While the majority of such catalyst require a single activation event to become cooperative, herein we report an exception to this trend. Specifically we demonstrate that Ru‐PN3P aminopyridine pincer catalyst, that lacks conventional reactivity with hydrogen upon typical one‐fold activation, can engage in this reactivity when a sequential two‐step activation is performed. The resulting anionic complexes readily activate molecular hydrogen and react further with CO2 showing the previously unknown reactivity that is critical for CO2 hydrogenation catalyst. While active in CO2 hydrogenation, Ru‐PN3Ps are significantly more efficient in hydrogenation of bicarbonates – a likely consequence of the chemistry of these pincers requiring formation of anionic complexes for hydrogen activation.