The next-generation functional covalent organic frameworks (COFs) have been synthesized using Staudinger cycloaddition in post-synthetic modification, Hosomi-Sakurai allylation in multicomponent one-pot reaction, and Hantzsch pyridine synthesis in pre-synthetic approach as marking these well-known organic transformations first time usage in the COF synthesis. The newly obtained cis-β-lactam and β-thiolactam COFs are suitable adsorbents for Hg2+ removal due to strong interactions between Hg2+ and active sites including N, O, and S. The homoallylamine COFs are post-synthetically methylated to produce cationic COFs, which showed >98% adsorption efficiencies for the removal of long chained perfluoroalkyl substances (PFAS). The first generation 1,4-dihropyridine-linked COFs (DHP-COFs) have never been reported in the reticular chemistry yet. From the series of DHP-COFs, DHP-COF-3 is first synthesized in this work, showing a high crystalline hexagonal structure in an ABC stacking pattern. The DHP-COF-2 and DHP-COF-4 have currently been studied for their structure simulations. A newly formed DHP linkage introduces both hydrogen-bond acceptor sites and hydrophobic domains within the frameworks, enabling electrostatic and hydrophobic interactions with structurally diverse PFAS for water treatment.