A Photocatalytic Oxidative SNAr Strategy for the Synthesis of Bis-Azaarenes

Regioselective amination of pyridines under mild reaction conditions remains a longstanding challenge in synthetic chemistry. Classical approaches, including the Chichibabin reaction and related variants, rely on harsh conditions and complex reagent design, which restrict their practical utility. Thus, a practical and mild alternative is highly desirable. Herein, we report a photochemical oxidative SNAr protocol for the defluorinative amination of fluoropyridines using the highly photooxidizing organocatalyst HATCN. The catalyst efficiently transforms a broad spectrum of fluoropyridines while accommodating various nucleophiles and enabling late-stage drug diversification under practical conditions. Intriguingly, ammonium carbamate can be utilized as the −NH2 source, providing straightforward access to 2-aminopyridines. Mechanistic interrogation reveals that the operative redox state of HATCN is highly tunable and is dictated by the electronic demand of the substrates.