Iridium-Catalyzed Hydrocarboxylation of Olefins with CO2 and H2.

CO2 is a greenhouse gas and a nontoxic, easily available and renewable C1 feedstock. H2 is a clean and cheap reductant that can be obtained from renewable energy. Olefins are platform chemicals that can be produced from a variety of raw materials such as petroleum, coal and renewable biomass. The production of carboxylic acids by combining olefins, CO2 and H2 is a sustainable and very promising protocol. However, only a few advances in this topic have been achieved because novel catalysts need to be developed. In this work, we demonstrate that a simple iridium-based catalyst could efficiently promote the synthesis of C2+ carboxylic acids via the reaction of olefins with CO2 and H2. The reaction was effectively accelerated by a simple iridium-based catalytic system at 170 °C, which may be applied to various olefin substrates. The catalytic mechanism was studied through a series of control experiments. The findings contribute to advancing the sustainable production of valuable products by the reaction of renewable CO2 and green H2 with platform chemicals.