Nickel/Nickel Oxide in Combination with a Photoredox Catalyst for the Reductive Carboxylation of Unsaturated Hydrocarbons with CO2 under Visible-Light Irradiation

Core-shell nickel/nickel oxide combined with ruthenium bipyridyl photoredox complex was found to be adept, reusable, and highly selective for the carboxylation of various aryl and olefinic compounds with carbon dioxide at ambient temperature under 20 W light-emitting diode light. The carboxylation of a range of aromatic hydrocarbons and olefins afforded excellent product yield under 1 atm pressure of carbon dioxide without adding any additive/cocatalyst. Importantly, in the case of styrenes, insertion of CO2 took place at the benzylic C-H, whereas in normal olefins it occurred at the terminal site selectively. Moreover, the developed photocatalyst was highly stable, which allowed it to be recycled successfully for subsequent runs with almost consistent efficiency.