Expedited Proton Relay in Enzyme‐Inspired Cobaloximes Facilitate Organic Transformations

Abstract

Developing a water‐soluble, oxygen‐tolerant, and acid‐stable synthetic H2 production catalyst is vital for renewable energy infrastructure. To access such an effective catalyst, we strategically incorporated enzyme‐inspired, multicomponent outer coordination sphere elements around the cobaloxime (Cl–Co–X) core with suitable axial coordination (X). Our cobaloximes with axial imidazole or L‐histidine coordination in photocatalytic HAT including the construction of anilines via a non‐canonical cross‐coupling approach is found superior compared to commonly used cobaloxime catalysts. The reversible Co(II)/Co(I) process is influenced by the axial N ligand's nature. Imidazole/ L‐histidine with a higher pKa promptly produces H2 upon irradiation, leading to the improved reactivity compared to previously employed axial (di)chloride or pyridine analogue.