Palladium-Catalyzed Synthesis of 4-Aminophthalazin-1(2H)-ones by Isocyanide Insertion

Palladium-catalyzed cross-coupling of a wide range of substituted o-(pseudo)halobenzoates and hydrazines with isocyanide insertion followed by lactamization efficiently affords 4-aminophthalazin-1(2H)-ones that are difficult to obtain regioselectively by classical methods.