Abstract
Utilizing CuxO nanoparticles supported on carbon nanotube as catalyst, visible-light could efficiently transform Glaser homo-coupling into Sonogashira cross-coupling. The isolated Sonogashira product yield is up to 0.58 mmol (sel. 97%) under visible-light irradiation while the Glaser product achieves 0.45 mmol (sel. 92%) in the dark for phenylacetylene and iodobenzene. We also discover that the active species under light irradiation is different from that in the dark. The visible light-driven adsorption of aromatic iodides on CuxO nanoparticles and light-excited copper(I) phenylacetylide intermediates together enables the high selectivity of Sonogashira product. The synergistic effect between Cu(II) and Cu(I) acetylide dimer complex enhances the Glaser product yield in the dark.
NSTL
Elsevier