Green One-pot Synthesis of α–aminonitriles by Nanocrystalline CeO2 as Heterogeneous Environmental Friendly Catalyst

Background: Despite the great attempts to modify the methodology for the synthesis of α-aminonitriles, a vast majority is associated with a variety of drawback. Therefore, the development of an environmentally friendly, inexpensive and effective procedure is still in demand. In order to reach these purposes, we decided to utilize CeO2 nanoparticles as catalyst in the synthesis of α-aminonitriles. Methods: In the present work, an attempt has been made to synthesize a simple method for the preparation of Cerium oxide nanoparticles that can be used as a green, heterogeneous and an effective catalyst for one-pot three component condensation of an amine, aldehyde and trimethylsilyl cyanide in solventless conditions for the expeditious synthesis of α-aminonitriles. Results: A wide range of α-aminonitriles were synthesized by using various aldehydes, ketones and amines with TMCN in the presence of CeO2 nanoparticles at room temperature and solvent free conditions. Ketones and substituted aldehydes with electron-donating and electron-withdrawing groups were efficiently transformed into desired α-aminonitriles. Heterocyclic aldehydes are converted to corresponding products in good yields. Also, the substituted amines reacted in good to excellent yield. In these reactions, separation and purification of products were very easy because CeO2 was not soluble in organic solvents. CeO2 nanoparticles could be recovered and reused for 8 runs without any significant loss of the catalytic activity. Conclusion: In conclusion, we have introduced CeO2 nanoparticles as efficient, mild and safe catalyst for the synthesis of α-aminonitriles by a one-pot three-component condensation of aldehydes or ketones and amines with trimethylsilyl cyanide. As a result, green reaction procedure, short reaction time, simple work-up procedure and high yield of the products are some of the advantages associated with this methodology.