Precisely Replicating Di‐Iron Active Sites of Monooxygenases Within COFs for Dioxygen Activation Independent of External Energy Under Ambient Conditions

Despite significant progress, designing artificial enzymes that can precisely replicate the active sites and functions of natural enzymes remains a significant challenge. Herein, we report a covalent organic framework (COF)-based artificial monooxygenase that mimic the [FeIII(µ₂-OH)]₂ active center of natural di-iron monooxygenase. The adjacent bipyridyl (bpy) linkers in COFs can precisely regulate to construct the [FeIII(µ₂-OH)]₂ active sites via hydrogen bonding interactions. The COF-based artificial monooxygenase effectively catalyzed C(sp³)─H bond oxidative transformations with > 99% selectivity, using O₂ as the only oxidant, which exhibited at least three times higher catalytic activity than the highest values reported for related systems without external energy under ambient conditions. Control experiments using a COF analogue with a different di-iron distance compared to that in natural monooxygenase verified the critical role of precisely formed [FeIII(µ₂-OH)]₂ active sites in achieving superior catalytic performance, which indicates the successful replication of the active sites and functions of natural monooxygenases in COFs. To our knowledge, this represents the first example of precisely replicating [FeIII(µ₂-OH)]₂ active sites into COFs to echo natural di-iron monooxygenase. This strategy not only expands the diversity for designing artificial enzyme catalysts but also opens new avenues for sustainable oxidation catalysis without external energy under ambient conditions.