Ligand- and Base-Free Synthesis of 1,3-Diynes Catalyzed by Low Loading of Heterogeneous Pd/C and CuI

Abstract

A facile and environmentally friendly synthetic method for a variety of symmetrical 1,3-diyne derivatives based on the Pd/C-CuI-catalyzed homocoupling reaction of terminal alkynes has been developed. The reaction was efficiently catalyzed by the -extremely low loading (0.01-0.03 mol%) of Pd/C and CuI (3 mol%) in the presence of molecular oxygen (O 2) as an oxidant without any phosphine ligands and bases.