Different NMR techniques are used to test protein-ligand binding in drug screening. In this research we have addressed the use of ¹⁹F-NMR, a powerful and highly sensitive technique, to measure the binding between fluorinated ligands designed via dynamic combinatorial library and β-catenin as a promising target for antitumor drugs. Moreover, the same technique allowed us to illustrate the binding constant for one of the ligands by using a non-fluorinated competitor ligand.