Isoindoloisoquinalinone, pyrroloisoquinolinone and benzo[a]quinolizinone units are constructed via intramolecular cyclization of the methoxy substituted N-phenethylimides using BBr3.
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