An Efficient and Selective Synthesis of Chalcones via Claisen-Schmidt Condensation Reaction Catalyzed by CuO@rGO Nano Catalyst

Abstract

The formation of carbon-carbon bonds is a fundamental approach in organic synthesis for deriving complex molecular architectures. The Claisen-Schmidt condensation is one of the most essential and efficient broad-spectrum reactions. The synthesis of α,β-unsaturated carbonyl compounds, particularly chalcones, by reductive addition relies heavily on this method. Herein we reported a highly efficient and selective method for synthesizing chalcones through the Claisen–Schmidt condensation reaction using a CuO@rGO (copper oxide supported on reduced graphene oxide) nano-catalyst. The CuO@rGO catalyst was synthesized via a solution combustion method and thoroughly characterized to assess its structural, morphological, and surface properties. The catalyst exhibited fascinating morphological characteristics and enhanced catalytic performance due to the presence of CuO nanoparticles supported on the reduced graphene oxide matrix. Under mild and environmentally friendly conditions, CuO@rGO significantly improved the reaction rate and yielded chalcones with excellent selectivity and yields reaching up to 96%. Systematic optimization of key reaction parameters, including reaction time, temperature, solvent, and catalyst loading, confirmed the robustness and versatility of the prepared catalyst across a range of substituted substrates, converting them into the desired product. Furthermore, mechanistic insights revealed that the active sites of Cu²⁺ supported on rGO promote an effective path for the formation of the desired product. Reusability tests confirmed the catalyst retained high activity over multiple cycles with negligible performance loss. Further analysis of the reused catalyst also showed no alteration in its physicochemical characteristics. This study highlights CuO@rGO as a promising and sustainable heterogeneous catalyst for the synthesis of α,β-unsaturated carbonyl compounds.

Graphical Abstract

A highly efficient CuO@rGO nano-catalyst was developed for the selective synthesis of chalcones via Claisen-Schmidt condensation. The catalyst demonstrated excellent activity under mild conditions, achieving up to 96% yield with high selectivity. Its reusability and green synthesis approach make it a promising candidate for sustainable organic transformations.