Fluorination of α‑Imino Gold Carbenes to Access C3‑Fluorinated Aza-Heterocycles

Reported herein is the fluorination of α-imino gold carbenes, generated in situ from azidoalkynes, to access substituted C3-fluorinated quinolones and indoles. The methodology has been applied for synthesizing C3-fluorinated quinolone- and quinoline-based natural products, including pseudanes (4 representative examples), chimanine A, and graveolinine. Mechanistic investigations, including NMR and SC-XRD analysis, reveal that NEt3·3HF reacts with the gold catalyst to generate a phosphine-ligated fluoride-bridged binuclear gold complex which then generates the active catalyst for this reaction.