Graphene quantum dots incorporated ZIF-67 for stabilization of Au nanoparticles: Efficient catalyst for A3-coupling and nitroarenes reduction reactions

Zeolitic imidazolate framework-67 (ZIF-67) functionalized with graphene quantum dots was prepared and utilized for the reduction of Au (III) and stabilization of Au nanoparticles. This newly prepared ZIF-67/GQD@Au was characterized with different techniques and employed as a capable heterogeneous catalyst for reduction of aromatic nitro compounds and A1-coupling reaction of alkynes, amines, and aldehydes in water solvent. Experiments indicate that this catalyst is able to reduce nitroarenes in short reaction times (10–20 min) in water at room temperature and corresponding amines were obtained in excellent yields (90–100%). Also, reactions of structurally different alkynes, amines, and aldehydes in the presence of this catalyst proceed effectively at 60°C and desired propargylic amine achieved in good to very good yields (76–88%) in water during 1 day. This catalyst displayed excellent stability and recyclability in both reactions and recycled for six runs with a small decrease in the activity.