Tandem one pot synthesis of 1,5-benzodiazocine-2-one by isocyanide based Ugi multicomponent reaction

We have developed an efficient one-pot, two-step reaction protocol for the synthesis of eight-membered 1,5-benzodiazocine-2-ones by Ugi four-center three-component coupling reaction (U-4C-3CR) and subsequent reductive cyclization using Fe/NH4Cl in protic solvent.