Metal-organic frameworks (MOFs)-derived ZrOSO₄@C for photocatalytic synthesis of benzimidazole derivatives

Heterocyclic moieties, such as benzimidazole, are examples of important nuclei that have found widespread use in a variety of scientific subfields, such as medical and applied chemistry. In this study, we described the photocatalytic synthesis of numerous different benzimidazole derivatives using a solid-state acid composed of zirconium oxosulfate embedded into carbon (ZrOSO₄@C). A metal-organic framework (MOF), known as UiO-66, was used as a precursor for the synthesis of ZrOSO₄@C via carbonization in the presence of sulfuric acid. ZrOSO₄@C was able to catalyze the reaction effectively, allowing for a condensation and cyclization to take place in a single vessel, which resulted in a high yield (77–98%) of benzimidazoles that were of high purity with the byproducts of water, and hydrogen (H₂) gas. Our catalyst allowed for an improvement in the synthesis of many different benzimidazole derivatives by using a wide array of aromatic aldehydes including aryl and heterocycles that included electron-donating or -withdrawing groups.