Scheme 1 C-C coupling via Heck's reaction. 1 H NMR spectra show no presence of any reactants indicating the complete conversion (Figure ). The peak assignments are suitable matches with the expected NMR signals. The highest peak corresponds to the solvent peak, i.e., DMSO. The active functional groups such as formyl show no side reactions such as oxidation (i.e., COOH) or reduction (i.e.,-CH2OH), indicating that the reaction condition is mild for substrates with active functional groups. The presence of electrondonating groups (e.g., NH2, OH) or electron-withdrawing groups in the substrate significantly affects the catalyst's conversion. This observation indicates that Pd NCs@COFs catalysts can be further used for a wide range of different substrates.