One pot synthesis of phenanthridines using a palladium-catalyzed cyclization of aromatic ketoximes with aryl iodides via Beckmann rearrangement

Abstract

The catalytic reaction of ketoximes with aryl iodides via a Beckmann rearrangement in the presence of a catalytic amount of Pd(OAc)₂, Ag₂O and ZnBr₂ gave substituted phenanthridines in good to excellent yield. In the reaction, aromatic ketoximes converted first to acetanilides in the presence of ZnBr₂/TFA via a Beckmann rearrangement followed by arylation in the presence of palladium complex. Furthermore, ortho-arylated acetanilides were converted to phenanthridine derivatives in the presence of a Hendrickson reagent.