NHC-Catalyzed Oxidation of Aromatic Aldehydes to Acids with CO₂

Significance

An efficient NHC-mediated transformation of aromatic aldehydes to carboxylic ­acids with carbon dioxide is reported by the authors. Using 15 mol% of the NHC catalyst together with 20 mol% DBU, various aromatic aldehydes can be oxidized to the corresponding carboxylic acids in good yields within ten minutes, while carbon dioxide is reduced to carbon monoxide. The authors found that the reaction worked more efficiently when a slow stream of carbon dioxide was passed through the reaction mixtures, cutting the reaction time from hours to minutes.