Computational and Experimental Studies on Dual Bridged Bimetallic Catalyst Enabled by the Synergistic Effect of Lewis Acid and eg Orbital Interaction

Unravelling the catalytic reaction mechanism is a long-term challenge for developing efficient catalysts. Recently, the blooming bimetallic catalyst have enabled to activate inert bonds and realize complex C-C formations. However, lack of catalytic mechanism and uncertain active catalyst led to hard efforts of trial and error. Herein, we theoretically discover a dual bridged Ni-Al hetero-bimetallic species that firstly verified by NMR experiments. This complex can be an active catalyst not only for nickel-catalyzed asymmetric cycloaddition via C-C activation, but also for more catalytic C-C formations through C-H activation. And an unprecedented tandem redox dehydrogenation mechanism was revealed to play an important role for the formation of active species. In contrast to the well-accepted mono-phosphinito complex, the advance of dual-complex relies on the synergistic effect of Lewis acid and eg orbital interaction with d_(z^2 ) orbital reoccupation and d_(x^2-y^2 ) orbital recombination, displaying the redox properties for accelerating both metal-H reductive dehydrogenation and C-C reductive elimination.