A Green Approach for Copper-Free Sonogashira Reaction of Aryl Halides with Phenylacetylene in the Presence of Nano-Pd/Phosphorylated Silica (SDPP/Pd0)

Abstract

Silicadiphenyl phosphinite (SDPP) is used as the solid support for the generation of nano SDPP/Pd(0) from PdII as pre-catalyst. This nano catalyst was used for the efficient copper-free Sonogashira reaction of aryl halides in PEG-200 as a solvent. The nano Pd(0) that can be used as pre-prepared or as in situ-generated catalyst exhibited excellent reactivity and stability in the Sonogashira cross-coupling reactions with different aryl iodides, bromides, and also chlorides. This heterogeneous catalyst can be easily recovered and reused in several runs. The use of PEG as solvent and K2CO3 as inorganic base together with the heterogeneous nature of the reaction can be considered as green conditions for this reaction.