Synthesis of Azulenopyridinones through Palladium‐Catalyzed Oxidative [4+2] Cyclization Reactions of N‐Methoxyazulene‐1‐ and 2‐carboxamides with Alkynes

Palladium‐catalyzed oxidative [4+2] cyclization reactions were developed from the C−H activation reaction of N‐methoxyazulene‐1‐ and 2‐carboxamides with symmetrical and unsymmetrical alkynes under a molecular oxygen atmosphere, producing azulenopyridinone derivatives with novel azulene skeletons in good to excellent yields with a wide substrate scope and excellent functional group tolerance.