Ir-Porphyrin-Based Metal-Organic Framework as a Dual Metallo- and Photocatalyst for Inert Alkyl C(sp3)-H Bond Activation and Direct Functionalization

The activation and transformation of inert alkyl C(sp(3))-H bonds to obtain high-value fine chemicals by sustainable solar energy are of great significance. Herein, by incorporating Ir-III-porphyrin into metal-organic frameworks (MOFs) to stabilize the highly active carbene, we reported a new approach to combining metallo- and photocatalysis to efficiently accelerate carbene migratory insertion and C-H bond activation via the radical coupling pathway for inert alkane functionalization. The in situ-formed carbene was restricted into the pores of MOFs to produce Ir-III-carbene, allowing the first-time isolation and structural characterization of the Ir-III-carbene intermediate which are not stabilized by a heteroatom. The product of the reaction, especially the cyclic ethers as substrates, suggested that the functionalization of the a position of the alkoxy group was favored. Additionally, the new approach could be extended to stabilize the metal carbene intermediates to realize C(sp(3))-H bond alkylation and arylation.

Automated summary

By stabilizing highly active carbenes in metal-organic frameworks, efficient acceleration of carbene migratory insertion and C-H bond activation was achieved, leading to inert alkane functionalization. The first-time isolation and structural characterization of Ir-III-carbene intermediates were successfully conducted.