Synthesis of 1,4-diarylsubstituted 1,3-diynes through ligand-free copper-catalyzed oxidative decarboxylative homocoupling of aryl propiolic acids

摘要

An efficient method of ligand-free Cu-catalyzed oxidative decarboxylative homocoupling of aryl propiolic acids was developed. When CuI was employed as the catalyst and I_2 as the oxidant, the decarboxylative homocoupling reaction for C_(sp)-C_(sp) bond formation in DMSO underwent smoothly to afford the corresponding 1,4-disubstituted 1,3-dialkynes in good to excellent yields without any organic ligands. This catalytic system was applicable to aryl propiolic acids bearing different steric, electronic, and functional groups.