Spontaneous α‐C−H Carboxylation of Ketones by Gaseous CO<sub>2</sub> at the Air‐water Interface of Aqueous Microdroplets
Pallab Basuri, Sinchan Mukhopadhyay, K. Satish Reddy, Keerthana Unni, B. K. Spoorthi, Jenifer Shantha Kumar, Sharma S. R. K. C. Yamijala, Thalappil Pradeep
Abstract
Abstract We present a catalyst‐free route for the reduction of carbon dioxide integrated with the formation of a carbon‐carbon bond at the air/water interface of negatively charged aqueous microdroplets, at ambient temperature. The reactions proceed through carbanion generation at the α‐carbon of a ketone followed by nucleophilic addition to CO 2 . Online mass spectrometry reveals that the product is an β‐ketoacid. Several factors, such as the concentration of the reagents, pressure of CO 2 gas, and distance traveled by the droplets, control the kinetics of the reaction. Theoretical calculations suggest that water in the microdroplets facilitates this unusual chemistry. Furthermore, such a microdroplet strategy has been extended to seven different ketones. This work demonstrates a green pathway for the reduction of CO 2 to useful carboxylated organic products.