A Metal-Organic Framework as a Multiphoton Excitation Regulator for the Activation of Inert C(sp3)-H Bonds and Oxygen

The activation and oxidization of inert C(sp(3))-H bonds into value-added chemicals affords attractively economic and ecological benefits as well as central challenge in modern chemistry. Inspired by the natural enzymatic transformation, herein, we report a new multiphoton excitation approach to activate the inert C(sp(3))-H bonds and oxygen by integrating the photoinduced electron transfer (PET), ligand-to-metal charge transfer (LMCT) and hydrogen atom transfer (HAT) events together into one metal-organic framework. The well-modified nicotinamide adenine dinucleotide (NAD(+)) mimics oxidized Ce-III-OEt moieties to generate Ce-IV-OEt chromophore and its reduced state mimics NADC via PET. The in situ formed Ce-IV-OEt moiety triggers a LMCT excitation to form the alkoxy radical EtO center dot, abstracts a hydrogen atom from the C(sp(3))-H bond, accompanying the recovery of Ce-III-OEt and the formation of alkyl radicals. The formed NAD(center dot) activates oxygen to regenerate the NAD(+) for next recycle, wherein, the activated oxygen species interacts with the intermediates for the oxidization functionalization, paving a catalytic avenue for developing scalable and sustainable synthetic strategy.

Automated summary

The article introduces a novel multiphoton excitation approach to activate inert C(sp(3))-H bonds and oxygen, which enables oxidation reactions and the development of sustainable synthetic strategies through integration of various events.