ZnO Nanoparticles Embedded on a Reduced Graphene Oxide Nanosheet (ZnO−NPs@r‐GO) as a Proficient Heterogeneous Catalyst for a One‐Pot A<sup>3</sup>‐Coupling Reaction
Dikin Patel, Chetan K. Modi, Prafulla K. Jha, Himanshu Srivastava, S. R. Kane
Abstract
Abstract This study reports a simple and facile route for the synthesis of ZnO nanoparticles (ZnO−NPs) decorated on reduced graphene oxide nanosheet (ZnO−NPs@r‐GO) as a heterogeneous catalyst and tested over multicomponent one‐pot A 3 ‐coupling reaction. The reduction of graphene oxide with the anchoring of ZnO−NPs on the r‐GO nanosheet was observed through the X‐ray diffraction patterns, Raman, FTIR, and XPS results of the ZnO−NPs@r‐GO sample. ZnO−NPs (average particle size of 3.4±1.5 nm) with uniform size distribution over r‐GO nanosheet were substantiated through HRTEM analysis. Impressively, ZnO−NPs@r‐GO significantly used for A 3 ‐coupling reaction with different aromatic aldehydes, active methylene compounds, and urea and under the optimized reaction conditions gave exceptional activity to produce synthetically valuable 3,4‐dihydropyrimidinones products (possessing diverse therapeutic and pharmacological properties) i. e. 97 % isolated yield of the product. In addition, excellent reusability up to 4 repeated cycles are the key advantages of the present catalyst used for this multicomponent A 3 ‐coupling reaction.