Transition-Metal Oxos as the Lewis Basic Component of Frustrated Lewis Pairs

摘要

The reaction of oxorhenium complexes that incorporate diamidopyridine (DAP) ligands with B(C_6F_5)_3 results in the formation of classical Lewis acid-base adducts. The adducts effectively catalyze the hydrogenation of a variety of unactivated olefins at 100 ℃. Control reactions with these complexes or B(C_6F_5)_3 alone did not yield any hydrogenated products under these conditions. Mechanistic studies suggest a frustrated Lewis pair is generated between the oxorhenium DAP complexes and B(C_6F_5)_3, which is effective at olefin hydrogenation. Thus, we demonstrate for the first time that the incorporation of a transition-metal oxo in a frustrated Lewis pair can have a synergistic effect and results in enhanced catalytic activity.