Aminophthalimide as a Protected Nitrogen Source for N-Insertion to Indenones

Nitrogen scanning is central to medicinal chemistry, yet N-positional variants and N–H analogues often require de novo synthesis. We report a nitrene-based, two-step one-pot formal N–H insertion into indenones to access isoquinolinones. N -Aminophthalimide, activated by PIDA, aziridinates the C═C bond and the resulting N-NPhth intermediate undergoes acid-promoted rearrangement in one pot. The method tolerates diverse substrates, including previously unreactive 2-alkyl and strongly electron-poor enones, and enables easy deprotection to N–H isoquinolinones.