Synthesis of Carboxylic Acids via Reaction of Ketones/Aldehydes with CO2 and H2

Synthesis of basic C2+ chemicals using CO2 and H2 is very promising. Herein, we present a protocol for the synthesis of different carboxylic acids by the reaction of ketones or aldehydes with CO2 and H2. The catalytic system consisted of the IrCl3 catalyst, LiI promoter, and acetic acid solvent. The yield can reach 52.9% based on the cyclohexanone substrate which can be derived from biomass. Various Cn ketones and aldehydes could be used as a substrate in the reaction, where the corresponding Cn+1 carboxylic acids were obtained. According to the mechanistic study, the reaction involved substrate conversion, reverse water–gas shift (RWGS) reaction, and carbonylation. This strategy provides an optional way of carboxylic acid production and CO2 utilization.