Tri-1-naphthylphosphine is primarily used as a ligand in coordination chemistry and catalysis. Its bulky structure makes it effective in stabilizing metal complexes, particularly in transition metal-catalyzed reactions. It is often employed in cross-coupling reactions, such as Suzuki-Miyaura and Heck reactions, where it enhances selectivity and efficiency. Additionally, it finds applications in the synthesis of organic compounds, including pharmaceuticals and fine chemicals, due to its ability to facilitate challenging transformations. Its use in asymmetric catalysis is also notable, as it can induce chirality in the resulting products.