Cu₂O–phthalate coordination composite catalyzed synthesis of dihydropyrimidinone derivatives: Structural characterization, antimicrobial evaluation and molecular docking studies

A series of dihydropyrimidinone (DHPM) derivatives was synthesised via a one-pot Biginelli multicomponent reaction using a Cu₂O–Phthalate Coordination Composite (Cu-CC) as an efficient heterogeneous catalyst at room temperature. The Cu-CC catalyst was thoroughly characterized by FTIR, XRD, SEM, EDS, TGA, and BET analyses, suggesting a hybrid copper–carboxylate composite with rod-like morphology, thermal stability up to ∼250 °C, and a BET surface area of 4.41 m²g⁻¹ . Five DHPM derivatives (SD-001, SD-004, SD-008, SD-010, and SD-011) were obtained in good yields (≈87–94%) and evaluated for antimicrobial activity using the agar well diffusion method. Halogen-substituted derivatives (SD-001, SD-008, and SD-011) exhibited moderate antibacterial activity, producing inhibition zones of up to 18 mm against Escherichia coli and 15 mm against Staphylococcus aureus at 100 µL concentration, while SD-010 displayed selective antifungal activity against Candida albicans (13 mm). Molecular docking studies against seven microbial protein targets revealed favourable binding affinities (−7.1 to −7.9 kcal mol⁻¹), particularly for halogenated compounds toward dihydrofolate reductase and DNA gyrase B, closely approaching native ligand scores. The combined experimental and computational findings suggest preliminary structure–activity trends and underscore the utility of Cu-CC catalysis for accessing bioactive DHPM scaffolds.