New approach to synthesis of tri(1-naphthyl)phosphine (Np ₃ P) and its application for design of new Pd(II) and Cu(I) complexes are reported. This phosphine has been prepared in 32% yield through exhaustive P–H arylation of РН ₃ with 1-chloronaphthalene in the superbasic t-BuOK/DMSO system at 70 °C. The Np ₃ P was found to readily reacts with chloro-bridged dimers, [(κ ² -C,N)Pd(μ-Cl)] ₂ (κ ² -C,N = PhCH ₂ NMe ₂ (2a) or FcCH ₂ NMe ₂ (2b), to give new mononuclear palladacycles [(κ ² -C,N)Pd(Np ₃ P)Cl] (3, 4), in which metal has a square-planar geometry. These complexes show good catalytic activity in the Sonogashira reaction under low catalyst loadings (2 mol% Pd) and relatively mild conditions. We also synthesized and characterized first Cu(I) complex with Np ₃ P, namely, [Cu(phen)(Np ₃ P)I], that exhibits red emission (λ _max = 650 nm) at room temperature.