The superiority of non-frustrated over frustrated Lewis pairs in the copper-catalyzed hydrogenation of CO2 to formate

Bertrand and we had found that typical frustrated Lewis pairs (FLPs), well-known to activate H2, were less efficient than non-frustrated Lewis Pairs (n-FLPs) for the hydrogenation of CO2 to formate in the presence of a copper hydride. Herein, through experimental and computational studies, a possible mechanism was proposed. We show that moderately bulky bases, which formed n-FLPs with tris(pentafluorophenyl)borane (BCF), are also able to activate H2 and serve as catalyst for the hydrogenation of CO2 to formate. Though FLPs are super active for H2 activation, it prevents the formation of active Cu-H. Thus, FLPs were less efficient for the hydrogenation of CO2 to formate. We expect these results to inspire and act as a guiding principle toward the development of novel Lewis pair catalyzed reactions.