Repurposing the Ligand Framework through a PCET Process to Bypass the Alkoxide Trap in N-Alkylation

The N-alkylation of amines with alcohols is a cornerstone transformation for synthesizing valuable chemicals, yet its catalysis with earth-abundant 3d metals is crippled by the “alkoxide trap”─a deep thermodynamic sink that kinetically blocks the catalytic cycle. Here, we demonstrate a powerful strategy that completely bypasses this conventional high-barrier pathway by repurposing the catalyst’s ligand framework into an active hydrogen shuttle. This concept is realized in a cobalt single-atom catalyst where coordination engineering via controlled pyrolysis forges a tailored asymmetric Co–N2C2 structure. Instead of forming a stable metal-alkoxide, the reaction proceeds through a designed base-initiated proton-coupled electron transfer (PCET) mechanism where the ligand itself mediates the critical hydrogen transfer steps. The catalyst achieves moderate to high yields and broad scope in the N-alkylation of diverse arylamines and alcohols under mild conditions. This work establishes ligand-framework participation as a powerful design principle for catalyst development, offering a generalizable blueprint for overcoming fundamental thermodynamic constraints in catalysis and unlocking the potential of earth-abundant metals.