A highly efficient and recyclable CuI@UiO-67-bpy catalyst for direct sp2 C–H arylation of azoles†
Abstract
A CuI@UiO-67-bpy (MOF II) catalyst was successfully synthesized by immobilizing a small amount of CuI onto the zirconium-based MOF (UiO-67-bpy, MOF I). Copper-doped CuI@UiO-67-bpy has an isostructural nature with the parent UiO-67 framework and a large surface area of approximately 1285 m2 g−1. Moreover, the material was thoroughly characterized using SEM, PXRD, TGA, FTIR, and XPS methods. The as-synthesized CuI@UiO-67-bpy catalyst can be an efficient heterogeneous catalyst for promoting C–H arylation of 1,3,4-oxadiazoles with aryl iodides and benzoxazoles or benzothiazoles with diaryliodonium salts. Furthermore, the catalyst was recoverable and reusable, maintaining a high catalytic activity even after three cycles. The combination of the advantages of both homogeneous molecular CuI catalysts and solid MOF structures in this system may bring new opportunities for the development of highly active heterogeneous copper catalysts for a variety of Cu-catalyzed transformations.