In this study, copper and amine-free photosensitized Sonogashira-Hagihara coupling reaction using Pd(OAc)2 and p-nitrobenzophenone in N,N-dimethylformamide(DMF) under blue LED irradiation was reported. Effect of benzophenone, p-methoxybenzophenone and p-nitrobenzophenone as photosensitizers in Sonogashira-Hagihara reaction were studied in which higher yields were achieved using p-nitrobenzophenone. In situ preparation of palladium nanoparticles and the effect of p-nitrobenzophenone were confirmed using UV–Vis and dynamic light scattering (DLS).It was proposed that the DMF affected the formation and stabilization of palladium nanoparticles. Using this catalytic system, aryl iodides and bromides were reacted efficiently with alkynes between 25 and 60 °C.