Utilization of Oxidovanadium(IV) Porphyrin as a Catalyst for One-Pot, Four-Component Synthesis of Bioactive Pyranopyrazoles and its Anticancer Potential

The novel β-functionalized porphyrin ligand 2-(1H-imidazo[4,5-<i>f</i>][1,10]phenanthroline-2-yl)-5,7,8,10,15,17,18,20-octaphenylporphyrin (H₂OPP(Phen)) and its vanadyl(IV) complex, 2-(1H-imidazo[4,5-<i>f</i>][1,10]phenanthroline-2-yl)-5,7,8,10,15,17,18,20-octaphenylporphyrinatooxidovanadium(IV) (VOOPP(Phen)), were synthesized in high yields (84-90%) and fully characterized by UV-Vis, NMR, EPR, MALDI-MS, and elemental analysis. The catalytic performance of VOOPP(Phen) was investigated in a one-pot four-component synthesis of bioactive pyranopyrazole derivatives using ethanol as a green solvent. The protocol afforded products in good yields (up to 94%) without chromatographic purification. The catalyst exhibited remarkable efficiency, with high turnover numbers (409-467) and turnover frequencies (545-622 h^-1), outperforming previously reported systems. VOOPP(Phen) was readily recyclable and retained its activity over seven consecutive cycles. A plausible reaction mechanism was proposed and supported by the isolation and characterization of key intermediates. Furthermore, cytotoxicity studies against MCF-7 breast cancer cells revealed that VOOPP(Phen) induced significant apoptosis, reducing cell viability by over 50% at 40 μM, whereas H₂OPP(Phen) showed lower activity. Fluorescence and morphological analyses confirmed concentration-dependent apoptotic cell death.