Palladium‐Catalyzed [3+3] Annulation of Vinyl Chromium(0) Carbene Complexes through Carbene Migratory Insertion/Tsuji–Trost Reaction

Vinyl chromium(0) Fischer carbene complexes were employed as the source of π‐allylic palladium species for catalytic 3+3] annulation under palladium catalysis. Mechanistically, this transformation is proposed to involve carbene migratory insertion and intramolecular Tsuji–Trost reaction as the key steps. Substituted six‐membered heterocyclic flavonones and quinolines are obtained, depending on the nucleophilic functional group on the coupling partners.