Activation of imide carbonyl group with trifluoromethanesulfonic acid facilitates the intramolecular cyclization of phenethylphthalimides to give a fused isoindoloisoquinolinone skeleton. The first one pot regioselective synthesis of isoindoloisoquinolinone alkaloid (±)-nuevamine has been successfully executed using this methodology.
isoindoloisoquinolinones, pyrroloisoquinolinones, and benzo[a]quinolizinones were successfully assembled from the corresponding imides by using a TfOH-mediated (TfOH = trifluoromethanesulfonic acid) imidecarbonylactivation and cyclization strategy. By employing this simple method, the isoquinoline alkaloids crispine A, trolline/oleracein E, and erythrinarbine were successfully synthesized in racemic form. The reaction