Phosphine and Copper-free Sonogashira coupling reaction catalyzed by lignin supported palladium nanoparticles

Lignin supported palladium nanoparticles (lignin@Pd-NPs) with an average size of 1-5 nm synthesized by green procedure was successfully explored in phosphine and copper-free Sonogashira C-C coupling reaction of various aryl halides with phenyl acetylene under aerobic conditions. It was found that the catalyst exhibited a high activity resulting desired products in 90-95 % yields. The catalyst was heterogeneous and was recovered by filtration and then recycled up to 3 consecutive reactions of the iodobenzene and phenyl acetylene under similar conditions resulting 93 to 88 % yields of diphenylacetylene. (C) 2018 Elsevier Ltd. All rights reserved.