Copper‐Catalyzed [3+2] Annulation of Pyridinium Ylides with α‐CF3 Ketones: Synthesis of Functionalized 2‐Fluoroindolizines

Abstract A copper‐catalyzed [3+2] annulation of the in situ generated pyridinium ylides with α‐CF 3 ketones was realized, in which α‐CF 3 ketones first acted as the synthetic equivalents of unstable fluoroalkynones. With this protocol, a series of functionalized 2‐fluoroindolizines were afforded in moderate to good yields under ambient conditions with air as the oxidant.