Simplified Version of the Eschweiler-Clarke Reaction.

The traditional Eschweiler-Clarke reaction is a three-component process involving formaldehyde, amine, and formic acid. In this work, we showed that the reductive potential of formaldehyde was sufficient to provide methylation of secondary amines in the absence of acidic additives. Various acid-sensitive moieties remain intact under developed conditions. The scalability of the elaborated approach was shown for several products. Synthesis of the antifungal agent butenafine demonstrated the preparative utility of the developed approach.

Air-Stable Arene Manganese Complexes as Catalysts for the Syngas-Assisted Direct Reductive Amination, Cyanation of Aldehyde, and CO2 Fixation by Epoxide with High Functional Groups Tolerance.

Manganese complexes [(arene)Mn(CO)3]+ were prepared in one step from arenes and Mn(CO)5Br. They were found to be efficient catalysts in the carbonyl cyanation with TMSCN, CO2 fixation by epoxides, and direct reductive amination in the presence of syngas. The amination reaction tolerated various reducible functional groups. The synergy of carbon monoxide and hydrogen in syngas provides high efficiency of the catalytic system. The developed protocols do not require an inert atmosphere, and the catalysts can be handled in air.