Direct use of dioxygen as an oxygen source: catalytic oxidative synthesis of amides.

The first transition-metal-catalyzed direct oxidative synthesis of amides by using dioxygen as an oxygen source has been developed under mild conditions, in which DBU was used as the key additive. The present methodology, which utilizes dioxygen as an oxidant and oxygen source and cheap copper salts as catalysts, opens up an interesting and attractive avenue for the synthesis of amide functionality.