Iridium-Catalyzed Selective Hydrogenation of 3‑Hydroxy­pyridinium Salts: A Facile Synthesis of Piperidin-3-ones

The selective hydrogenation of 3-hydroxy­pyridinium salts has been achieved using a homogeneous iridium catalyst, providing a direct access to 2- and 4-substituted piperidin-3-one derivatives with high yields, which are important organic synthetic intermediates and the prevalent structural motifs in pharmaceutical agents. Mild reaction conditions, high chemoselectivity, and easy scalability make this reaction highly practical for the synthesis of piperidin-3-ones.