Palladium-catalyzed cascade imidoylative Heck annulation of functionalized isocyanides for the construction of 1,4-diazepinones.

Abstract

A palladium-catalyzed cascade imidoylative/Heck annulation of functionalized isocyanides is reported, providing convenient and efficient access to 1,4-diazepinones bearing an exocyclic alkene. Using readily available alkene-tethered isocyanides and aryl iodides as starting materials, this protocol delivers a range of seven-membered N-heterocycles in moderate to excellent yields (up to 92%). The reaction features a sequential insertion of isocyanide and alkene into the aryl-Pd intermediate, which enables the formation of two C-C bonds in a single operation. This strategy not only offers a practical route to medium-sized diazepinone frameworks but also significantly broadens the synthetic utility of imidoylative annulation chemistry.