Iron‐Doped Hydrotalcite: A Heterogeneous Catalyst for the Selective Synthesis of 2‐Substituted Benzimidazoles and Benzothiazoles Using Alcohols and Solvent‐Free Reaction Conditions

Abstract

A heterogeneous iron‐anchored calcium aluminum hydrotalcite is prepared and characterized appropriately using powder X‐Ray diffraction, scanning electron microscope, energy dispersive X‐Ray, transmission electron microscope, ourier‐transform infrared, and thermogravimetric analysis. Further, X‐Ray photoelectron spectroscopy confirms the presence of Fe in +3 oxidation state. The prepared heterogeneous catalyst is applied to the selective synthesis of 2‐substituted benzimidazole and benzothiazole derivatives using alcohols and under solvent‐free reaction conditions. The developed protocol is applicable to a broad range of substrates, including difficult aliphatic substrates. The Fe/CaAl hydrotalcite catalyst can also be recycled and reused effectively for two catalytic cycles. Furthermore, control experiments reveal the role of the catalyst and the plausible mechanistic pathway of the reaction.