Manganese-Catalyzed Multicomponent Synthesis of Tetrasubstituted Propargylamines: System Development and Theoretical Study

Herein, we report a catalytic system based on the earth-abundant manganese for the ketone, amine, alkyne (KA(2)) reaction. The efficiency of manganese manifests at relatively high temperatures, combined with sustainable reaction conditions, and provides a tool for accessing propargylamines from structurally diverse starting materials, including synthetically relevant and bioactive molecules. Our efforts were also aimed at shedding light on the catalytic mode of action of manganese in this transformation, in order to explain its temperature-related behavior. The use of computational methods reveals mechanistic aspects of this reaction indicating important points regarding the reactivity of both manganese and ketones.