Graphene–ZnO@SiO2 hybrid: An efficient and solid acid catalyst for synthesis of azlactones under ultrasound irradiation

Document Type: Articles


Material and Nuclear Fuel School, Nuclear Science and Technology Research Institute, End of North Karegar Ave. P.O. Box: 14399-51113, Tehran, Iran.


The central theme of this article is how to explore a novel route to fabricate graphene– ZnO@SiO2 hybrid by a covalent process. The synthesis procedure consists of three-steps: (1) synthesis of ZnO nanoparticles, (2) ZnO nanoparticles modification by tetraethyl orthosilicate and (3-aminopropyl) triethoxysilane after introduction of amino groups on its surface, (3) the covalent attachment of ZnO@SiO2 onto the graphene surface by the amidation reaction between amino group of ZnO@SiO2 and carboxylic group of graphene. This hybrid was then used as a catalyst for the synthesis of azlactones obtained by Erlenmeyer synthesis from aromatic aldehydes and hippuric acid under the ultrasonic irradiation. The protocol offers advantages in terms of higher yields, short reaction times, mild reaction conditions, and reusability of the catalyst.


[1] H. Moghanian, M. Shabanian, H. Jafari, C. R. Chim. 15 (2012) 346–349.
[2] B. Shafiee, L. Hadian, A.R. Khosropour, RSC Adv. 6 (2016) 19861–19866.
[3] T. Clearly, T. Rawalpally, N. Kennedy, F. Chavez, Tetrahedron Lett. 51 (2010) 1533-1536.
[4] K.A. Monk, D. Sarapa, R.S. Mohan, Synth. Commun. 30 (2000) 3167-3170.
[5] P.A. Conway, K. Devine, F. Paradise, Tetrahedron 65 (2009) 2935-2938.
[6] T. Clearly, J. Brice, N. Kennedy, L.F. Chavez, Tetrahedron Lett. 51 (2010) 625-628.
[7] S. Paul, P. Nanda, R. Gupta, A. Loupy, Tetrahedron Lett. 45 (2004) 425-427.
[8] S.G. Patil, R.R. Bagul, V.M. Kamble, V.A. Navale, J. Chem. Pharm. Res. 3 (2011) 285-290.
[9] F. He, J. Fan, D. Ma, L. Zhang, C. Leung, H.L. Chan, Carbon 48 (2010) 3139-3144.
[10] S. Sadjadi, S. Sadjadi, R. Hekmatshoar, Ultrason. Sonochem. 17 (2010) 764–767.
[11] M.M. Heravi, S. Sadjadi, S. Sadjadi, H.A. Oskooie, F.F. Bamoharram, Ultrason. Sonochem. 16 (2009) 708–710.
[12] A.M. Atta, H.A. Al-Lohedan, S.A. Al-Hussain, Int. J. Mol. Sci. 16 (2015) 6911-6931.
[13] Y. Si, E.T. Samulski, Nano Lett. 8 (2008) 1679–1682.
[14] N.L. Zhou, N. Meng, Y.C. Ma, X.M. Liao, J. Zhang, L. Li, Carbon 47 (2009) 1343–1350.
[15] Y.H. Deng, C.H. Deng, D. Yang, C.C. Wang, S.K. Fu, X.M. Zhang, Chem. Commun. 44 (2009) 5548–5550.
[16] Y.Y. Liang, L.M. Zhang, Biomacromolecules 8 (2007) 1480–1486.
[17] Y.W. Cao, J.C. Feng, P.Y. Wu, Carbon 48 (2010) 1683–1685.
[18] M.A. Pasha, V.P. Jayashankara, K.N. Venugopala, G. Krishna Rao, J. Pharmacol. Toxicol. 2 (2007) 264-270.
[19] A. Momeni Tikdari, S. Fozooni, H. Hamidian, Molecules 13 (2008) 3246-3252.