Pd NCs@COFs offer several advantages for being a catalyst for C-C cross-coupling. The catalyst exhibits high catalytic activity with complete conversion. It can be used for a wide range of different substrates. The synthesis procedure for the palladium nanocrystals is straightforward. It requires the addition of the metal salts into the COFs materials that enable coordination to palladium (Pd 2+ ) ions before the in-situ reduction to Pd 0 . The presence of nitrogen into the COFs frameworks enhanced the stability of Pd NCs . Thus, there is no dramatic change in the catalyst performance for several runs. There is no observation for palladium leaching during the reaction.