Potassium-Ligand Cooperation Facilitated Chemical Bond Activation and Catalytic Hydrogenation.

Replacing conventional transition metals with main-group elements for chemical bond activation and catalysis is of increasing interest, yet alkali metals remain largely underexplored in this context. Herein, we introduce a new strategy for alkali metal-mediated catalysis based on metal-ligand cooperation (MLC) driven by dearomatization-aromatization of the ligand. Potassium pincer complexes bearing dearomatized picolyl ligands were synthesized and shown to activate a variety of molecules, including CO2, CS2, phenyl iso(thio)cyanates, ketones, and H2, thereby enabling the design of alkali metal catalysis. Notably, a dearomatized potassium complex efficiently catalyzed the hydrogenation of ketones and C─C multiple bonds, reactions that remain challenging in alkali metal catalysis. Density functional theory (DFT) calculations elucidated the electronic structures and bonding characteristics of the obtained complexes and provided mechanistic insight into the transformations. This work establishes a new paradigm in alkali metal chemistry and broadens the scope of MLC for bond activation and catalysis.