Efficient Silica-OSO₃H (SSA)-Catalyzed One-Pot Multicomponent Synthesis of 1,2,4,5-Tetrasubstituted 1H-Imidazoles: Molecular Docking, Antibacterial Activity, and Plausible Mechanism

A series of polysubstituted imidazoles were synthesized in good yields by employing stable and active silica-OSO₃H catalyst via a one-pot four-component approach. This new protocol has the advantages of inexpensive, nontoxic, and heterogeneous catalyst along with mild reaction conditions, short reaction times, and easy workup and purification procedures, which enhance its practicality. The synthesized imidazoles were subjected to molecular docking with some bacterial target enzymes (PDB IDs: 1KZN, 1BAG, 1D7U, 2XCT). Compounds 1k, 1e, 1o, and 1i showed the best docking scores on selected targets, –8.2, –8.4, –8.5, and –9.3 kcal/mol, respectively. Antibacterial evaluation of the synthesized compounds against S. aureus, B. subtilis, E. coli, and K. pneumoniae revealed their potential activity with MIC values of 64 to 100 µg/mL. Imidazoles containing another heterocyclic unit such as pyridyl or thienyl (1d, 1f, 1h, and 1m) showed better antibacterial activity than other analogues.