Cu(OTf)2 Enhanced Intramolecular Nucleophilic N-Arylation of 2-Amino-3-arylquinolines

In the presence of Cu(OTf)(2) (5 mol %) andKO( t )Bu, a synergistic effect of the N-arylation process on 2-amino-3-arylquinolines is observed.Within4 h, this method provides a wide variety of norneocryptolepine analogueswith good to excellent yields. Overall, a double heteroannulationstrategy for the synthesis of indoloquinoline alkaloids from nonheterocyclicprecursors is demonstrated. Mechanistic investigations establish thatthe reaction proceeds via the SNAr pathway. Despite moderateyields, the one-pot, two-step double heteroannulation illustratesthat this procedure is highly atom-efficient. Neocryptolepine, a naturalproduct, is also synthesized from indoloquinoline. A brief study ofthe photophysical properties of selected norneocryptolepine analoguesis also discussed.

Automated summary

In the presence of Cu(OTf)(2) (5 mol %) and KO(t)Bu, a synergistic effect of the N-arylation process on 2-amino-3-arylquinolines is observed. This method provides a wide variety of norneocryptolepine analogues with good to excellent yields within 4 hours. The reaction proceeds via the SNAr pathway and the one-pot, two-step double heteroannulation procedure is highly atom-efficient.