Heterostructured Ti-MOF/g-C3N4 driven light assisted reductive carboxylation of aryl aldehydes with CO2 under ambient conditions

The present work described an efficient photoredox-mediated synthesis of α-hydroxy acids from reductive carboxylation of aryl aldehydes with CO2 using heterostructures made up of titanium-based MOF (MIL-125-NH2) and g-C3N4 under visible illuminance. The developed protocol worked well for a number of aryl aldehydes having electron-donating substituents and afforded moderate to higher yields of the desired carboxylated products. The substrates having electron-withdrawing groups remained inefficient for the present transformation. The key advantages of the developed methodology include the utilization of CO2 at room temperature, higher product selectivity, and a highly stable and recyclable photocatalyst. Moreover, blank experiments support that the reaction is truly photocatalytic and light irradiation played a crucial role.