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

Abstract

The activation and transformation of inert alkyl C(sp3)-H bonds to obtain high-value fine chemicals by sustainable solar energy are of great significance. Herein, by incorporating IrIII-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 IrIII-carbene, allowing the first-time isolation and structural characterization of the IrIII-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 α position of the alkoxy group was favored. Additionally, the new approach could be extended to stabilize the metal carbene intermediates to realize C(sp3)-H bond alkylation and arylation.