Synthesis of rutaecarpine analogues by borrowing hydrogen strategy

A series of rutaecarpine analogues were synthesized in 11–90% yields via an iron (II) phthalocyanine‐catalyzed N‐alkylation reaction of 3‐hydroxyethyl quinazolinone‐linked indole. Mechanistic investigation revealed that the formation of C‐N bonds in the cyclization reaction occurs through intramolecular borrowing hydrogen annulation. The crucial intermediates in this process were verified by LC‐MS analysis and DFT calculations, further supporting the proposed mechanism. Furthermore, biological evaluation demonstrated that some of the synthesized rutaecarpine analogues exhibited good anti‐inflammatory activity.