Synergized\nMolecular Oxygen Activation in an Enzyme-Mimicking\nMetal–Organic Framework for Boosted C–H Bond Oxidation

Metal–organic frameworks (MOFs)\nhave experienced\nsignificant\nprogress and advancement in recent decades due to the multifarious\nmodifications and functionalization of their inherent structures.\nHowever, the development of synergistic all-in-one MOF catalysts with\nfunctionalized organic linkers and metal nodes has posed formidable\nchallenges. Here we construct an isostructural MOF, <b>TJU-101-NHPI</b>, using traditional Cu(II) paddle-wheel nodes as catalytic open metal\nsites (OMSs) and <i>N</i>-hydroxyphthalimide (NHPI) covalently\nembedded ligands as organocatalytic sites (OCSs) in spatial proximity.\nThe <b>TJU-101-NHPI</b> catalyst, in combination with the cocatalyst <i>t</i>-butyl nitrite, can overcome the longstanding paradox to\nselectively oxidize primary alcohols to aldehydes or acids in a specific\ntime-dependent manner. Moreover, the single <b>TJU-101-NHPI</b> MOF can directly activate O<sub>2</sub> to oxidize alkylarenes,\nresembling biomimetic enzymatic oxidation. The established catalytic\nsystems use O<sub>2</sub> as the exclusive oxidant and yield H<sub>2</sub>O as the sole byproduct, achieving nearly complete conversion\nand 100% selectivity in the majority of the oxidations (62 examples).\nControl experiments and computational studies reveal that the synergistic\nactivation of molecular oxygen and facilitated hydrogen atom transfer\n(HAT) between the OMSs and the OCSs lead to the generation of critical\nphthalimido <i>N</i>-oxyl radicals on the pore surface,\nthereby boosting the oxidation under mild conditions. This research\noffers a new concept of leveraging MOF organic linkers as cofactors\nand inorganic nodes as metal sites to mimic enzymes for superior catalysis.