Visible Light-Driven CO2 Insertion on Phenylacetylene to Phenylpropiolic Acid Using Soft-Oxometalates

Abstract

The visible light-driven CO2 insertion from phenylacetylene to acetophenone using soft-oxometalates (SOMs) as a photocatalyst is an important step in the pursuit of C–H activation. We have demonstrated a synergistic combination of Cu-based SOMs and Cs2CO3 at ambient pressure and temperature to lower the activation energy barrier for CO2 insertion. The water in the medium acts as a source of proton and the reaction is driven by Cu(II)/Cu(I) couple. The reaction yields a good amount of phenylpropiolic acid under mild condition. We further believe this work could open up a new avenue for direct CO2 insertion under mild condition.