Substituted 2-Phenyl Imidazolidines: Synthetic Strategies, Biological Activities, Mechanistic Insights, and Nanocarrier-Based Advancements

Substituted 2-phenyl imidazolidines present a structurally diversified family of heterocycles with several medicinal potentials. Their significance is due mostly to the presence of the phenyl group at the C-2 position, which enhances lipophilicity, rigidity, electronic distribution, and molecular recognition. This review summarises the current advances in the synthesis, biological activity, mechanistic understanding, and nanocarrier-based administration of 2-phenyl imidazolidine derivatives. Amongst the most successful synthetic methodologies described are the classical cyclisation processes, condensation pathways, urea/thiourea-based procedures, green chemistry approaches, and nanocatalyst-assisted techniques. These protocols ensure that highly functionalized derivatives are easily accessible. The biological activities of phenyl imidazolidines encompass anticancer, antibacterial, anti-inflammatory, CNS-modulating, antioxidant, and enzyme-inhibitory properties. Accordingly, a mechanistic study shows these phytochemicals interact with major molecular targets like DNA, tubulin, and other enzymes, leading to cell cycle arrest, induction of apoptosis, regulation of reactive oxygen species, and enzyme inhibition. The computational techniques enhance the optimisation based on SAR through the explanation of electrical behaviour and binding interactions. Recent advances in nanotechnology have enabled the encapsulation of these derivatives within polymeric nanoparticles, lipid-based carriers, metal-doped nano-systems, and hybrid nano-structures. These platforms improve therapeutic effectiveness owing to an increase in solubility, stability, and targeted delivery. This review combines synthetic, biological, mechanistic, and formulation factors to serve as a backbone for logical drug design. It highlights the potential of 2-phenyl imidazolidines as attractive scaffolding in the development of new medicinal compounds.