Pd-Catalyzed Three-Component Synthesis of Isoindolones and Phthalazones

Significance

A Pd-catalyzed, three-component cascade process for the synthesis of isoindolones or phthalazones is reported. The process involves a carbonylation of an ortho-iodo styrene to give an acylpalladium species, which is intercepted by a hydrazine nucleophile which, after a Michael addition, affords the final products. The product depends on whether a mono- (isoindolone) or disubstituted (phthalazine) hydrazine derivative is used. The yields range between moderate and good and the substrate scope is well studied. It is clear that, for the synthesis of the phthalazones, the choice of reaction conditions is crucial, since for the eight examples three different reaction conditions were employed.