Sonogashira coupling reactions with ligand-free heterogeneous nanoporous Pd catalyst

Abstract

The Sonogashira coupling reaction is one of the most important protocols for the production of aryl alkynes. In order to solve the problems existing in Sonogashira cross-coupling reaction, according to the application of nanoporous palladium in Suzuki and Heck cross-coupling reactions, nanoporous palladium was used as the sustainable catalyst for the Sonogashira cross-coupling reaction. A sustainable catalyst system was tested and optimized without cuprous ion, phosphine ligand, or amine additives. Nanoporous palladium catalyst remained stable over five cycles without significant leaching or loss of catalytic activity, and the desired alkynes were obtained in high yields.