Palladium-catalyzed Sonogashira coupling of amides: access to ynones via C-N bond cleavage.

The first palladium-catalyzed Sonogashira coupling of amides has been developed, which proceeds via a selective cleavage of the N-acylsaccharin C-N bond. Notably, the new approach employs N-acylsaccharins as coupling partners to give ynones in good to excellent yield. This protocol can be efficiently utilized in the synthesis of a broad array of ynones under low catalyst loading and Cu-free conditions.