Design and Introducing Quaternary Ammonium Hydroxide-Functionalized Graphene Oxide Quantum Dots as an Efficient Pseudo-Homogeneous Catalyst for Epoxidation of α,β-Unsaturated Ketones

In present work, design and synthesis of a novel pseudo-homogeneous catalyst is described. For this purpose, amine-functionalized graphene oxide quantum dots (N-GOQDs) were prepared from graphene oxide (GO) by a facile one-step oxidative fragmentation approach. The prepared N-GOQDs were then decorated with quaternary ammonium hydroxide groups. Various characterization techniques clearly revealed that the quaternary ammonium hydroxide‐functionalized GOQDs (N-GOQDs/OH) have been successfully synthesized. TEM image revealed that the GOQDs particles are almost regularly spherical in shape and mono-dispersed with particle sizes <10 nm. The utility of the catalyst demonstrated toward epoxidation of α,β -unsaturated ketones in the presence of aqueous H 2 O 2 as an oxidant at room temperature. The corresponding epoxide products were obtained in good to high yields. These procedure has the advantages of a green oxidant, high yields, involvement of non-toxic reagents and reusability of the catalyst without discernible loss in activity.