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

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 CO 2 atmosphere. The reversible reaction of CO 2 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 CO 2 , thus resulting in facile post-processing.