Carbon dioxide promoted reductive amination of aldehydes in water mediated by iron powder and catalytic palladium on activated carbon

•Pd/C/Fe mixture has been revealed to be an efficient system for the reductive amination.•With the promotion of CO2, water serves as solvent and terminal hydrogen source.•Various amine products are obtained in good to excellent yields.•This developed transfer hydrogenation system is controllable.•The work-up process could be inherently neutralized by simple depressurization.

A mixture of iron powder and catalytic palladium on activated carbon has been developed for reductive amination of various aromatic aldehydes, including 2-pyridinecarboxaldehyde, in water under CO2 atmosphere. The reversible reaction of CO2 with water could form carbonic acid and hydrogen transfer from water to Pd(0) took place with the presence of iron powder, leading to formation of high-active Pd hydrides for the reductive amination process. On the other hand, the reaction system could be inherently neutralized by ready removal of CO2, thus resulting in facile post-processing.

Graphical abstractA Pd/C/Fe mixture with water was developed to be an efficient transfer hydrogenation system for the reductive amination of various aromatic aldehydes under CO2 atmosphere.Figure optionsDownload full-size imageDownload high-quality image (93 K)Download as PowerPoint slide