A polysalen based on polyacylamide stabilized palladium nanoparticle catalyst for efficient carbonylative Sonogashira reaction in aqueous media

Abstract

A highly cross-linked polymer matrix polysalen based on acrylamide and N,N'-methylene-bisacrylamide (NNMBA) was successfully prepared. It has been proved that this type of polysalen is an effective support for immobilizing palladium complex. The polysalen may provide coordination sites for conjugation with a palladium catalyst to produce polysalen-Pd catalyst. The polysalen-Pd was firstly applied in phosphine-free carbonylative Sonogashira coupling reactions of aryl iodides with terminal alkynes to produce α,β-alkynyl ketones in 81-95% yields in aqueous media, which was much higher than that of homogeneous Pd-salen in 52% yield. Furthermore, the catalyst showed excellent recyclability without any significant loss in its activity.