An interesting ring-closing/ring-opening cascade reaction selectively induced by aliphatic primary amine for the synthesis of functionalized aminomaleimides is described. This work features phenolic hydroxyl as a traceless directing group that forms a critical six-membered intermediate and then a lactone ammonolysis/intramolecular amidation sequence. This two-step, one-pot practical protocol has broad substrate scope (39 examples) and delivers structurally diverse aminomaleimides in good to excellent yields.
Key words
aminomaleimides - ring-closing/ring-opening reaction - aliphatic primary amines - phenolic hydroxyl - directing group