Pd/C catalyzed Sonogashira coupling reaction of phenylacetylene in TX10 microemulsion

In absence of ligand, copper or amine, Pd/C catalyzed Sonogashira reactions of aryl iodides and bromides with phenylacetylene were performed well in TX10 microemulsions at 70 °C. Aryl iodides and activated aryl bromides were converted to the corresponding diaryl-substituted alkynes quantitatively within 30–150 min and the reactivity in the microemulsion was higher than that in biphasic system. The aqueous phase concentration has positive effect on the conversion. Hot filtration indicated than that the “heterogeneously” catalyzed Sonogashira coupling reaction was due to the “dissolved Pd-species”.