Vanadium(V<sup>IV</sup>)–Porphyrin-Based Metal–Organic Frameworks for Synergistic Bimetallic Activation of Inert C(sp<sup>3</sup>)–H Bonds
Yefei Wang, Liang Zhao, Guanfeng Ji, Cheng He, Songtao Liu, Chunying Duan
Abstract
Activation and selective functionalization of inert C(sp3)–H bonds remain one of the most challenging tasks in current synthetic chemistry. Herein, by decorating vanadium(VIV)–porphyrin into metal–organic frameworks (MOFs) to stabilize the active tertbutyl peroxide radical, we reported a new approach to accomplish inert C(sp3)–H bond activation by a synergistic bimetallic strategy via a hydrogen atom transfer process under mild conditions. The stabilized peroxide radical by VIV–porphyrin-based MOFs abstracted a hydrogen atom from the inert C(sp3)–H bonds for direct oxidization transformation utilizing environmentally friendly oxygen. Taking advantage of the high stability of Zr6 clusters, the new Zr–MOF was recyclable six times without a conversion efficiency decrease. From this foundation, {Mn3(μ3-O)} cluster nodes with potential unsaturated coordinated sites were introduced into MOFs to replace Zr6 clusters, realizing the pre-activation of substrates through the interaction between Mn nodes and substrates. The synergistic bimetallic activation effect of VIV–porphyrin and Mn nodes dramatically promoted the conversion efficiency and product selectivity for inert C(sp3)–H bond functionalization.