Sustainable route to antiviral furano-chalcones via microwave-assisted solvent-free synthesis with recyclable MgO

The increasing demand for sustainable chemical processes has driven the search for renewable feedstocks, environmentally benign catalysts, and energy-efficient methodologies. In this context, we report a solvent-free protocol for the Claisen–Schmidt condensation between biomass-derived furanic aldehydes and acetophenone. Commercial magnesium oxide (MgO) was employed as a recyclable heterogeneous catalyst and subjected to physicochemical characterization and recycling tests to evaluate its stability and reusability. Microwave (MW) irradiation was integrated to ensure rapid and homogeneous heating, leading to enhanced reaction efficiency and reduced processing times. The sustainability of the proposed approach was preliminarily assessed through green chemistry metrics, which confirmed its advantages over conventional methods. The obtained furano-chalcones were investigated for their antiviral potential in in vitro cell-based models against common human pathogenic viruses, such as human herpes simplex virus, Zika virus, rhinovirus and influenza virus. Their activity was specifically targeted against HSV type 2, highlighting their relevance as pharmacologically active scaffolds and warranting further optimization and investigation. Overall, this work combines renewable resources, recyclable catalysis, and energy-efficient techniques, offering a greener and versatile strategy for the synthesis of high-value bioactive compounds.