The Carboxylation of Organic Compounds by Carbon Dioxide

Abstract

The carboxylation of carbonyl, nitro, and nitrile compounds has been investigated in a dimethylformamide solution containing potassium phenoxide with special attention to the easiness of the reaction. Kinetic investigations carried out with the carboxylation of cyclohexanone at 0°led us to suggest that the carboxylation is initiated by the formation of a complex between potassium phenoxide and carbon dioxide (2 : 1) and that the transfer of carbon dioxide from the complex to the organic compounds to form carboxylates is the slow step. The latter step seems to be facilitated by the lower pK_a of the organic substrates.