Light-induced carboxylation of aryl derivatives with cooperative COF as an active photocatalyst and Ni(ii) co-catalyst

The photocatalytic carboxylation of aryl derivatives was demonstrated under CO2 at atmospheric pressure using a mesoporous covalent organic framework (COF) as the active photocatalyst with triethylamine (TEA) as a sacrificial electron source under visible light. A yield of greater than 91% of the isolated product was achieved with 5 mg of catalyst. The reaction cycle is dependent on the use of the Ni(dmg)2 co-catalyst and the sacrificial electron donor (TEA). The reaction does not occur in the absence of light (445 nm) even at elevated reaction temperature. We have also demonstrated that a yield of 32% of the isolated product could be obtained with the use of sunlight in the catalytic cycle. Additionally, this heterogeneous catalytic system was recyclable and reusable for several cycles.