Dual Cofactor Co-Decorated Covalent Organic Framework as an Electron Transfer Regulator for Biomimetic Dioxygen Activation

Mimicking the synergy of multiple active sites of oxygenase to achieve selective O₂ activation for various oxidations is a very challenging but meaningful task. By introducing the reduced nicotinamide adenine dinucleotide (NADH) active site dihydropyridine amido (DHPA) moiety and heme, a dual cofactor co-decorated covalent organic framework (COF) was obtained to duplicate the synergistically catalytic function of the cytochrome P450 for biomimetic O₂ activation. Covalent co-decoration of dual cofactors in COFs ensures the rapid photogenerated electron transfer from DHPA to heme Fe^III to generate Fe^II, selectively activating O₂ to form Fe^III−O₂^•− resembling the cytochrome P450 for improving the performance of alcohol oxidation, avoiding conventionally complex multistep cofactor shuttling and regeneration. Control experiments of a COF analogue containing heme but not DHPA suggested that this dual cofactor construction strategy renders COFs excellent activity and selectivity for O₂ activation. As far as we know, this represents the first case of introducing dual cofactor into COFs to echo the cytochrome P450. The well-defined structural characters and the finely modified bioactive properties open a new avenue to develop novel COFs, which not only augment the diversity of the COF family but also broaden the application of COFs in the field of biomimetic catalysis.