Regioselective Synthesis of <i>N</i>-Aminoisoindolones and Mono-<i>N</i>- and Di-<i>N,N</i>′-substituted Phthalazones Utilizing Hydrazine Nucleophiles in a Palladium-Catalyzed Three-Component Cascade Process

A palladium-catalyzed three-component cascade process for the synthesis of isoindolone and phthalazone derivatives is reported. The cascade process involves carbonylation of an aryl iodide/Michael acceptor to give an acylpalladium species which is intercepted by a hydrazine nucleophile. Intramolecular Michael addition follows to give either N-aminoisoindolones or mono-N- and di-N,N′-phthalazones depending on whether a monosubstituted or 1,2-disubstituted hydrazine nucleophile is used.