Selectfluor™-Mediated Tandem Fluorination and 1,3-Carbonyl Migration in ortho-Carbonyl Anilines: Charge-Transfer-Enabled ortho-Selectivity

An unprecedented tandem ortho-selective fluorination and 1,3-carbonyl migration in ortho-carbonyl anilines using selectfluor (TM) as the sole reagent is reported. The reaction is transition-metal free, does not require any pre-functionalization, takes place under ambient conditions, and yields ortho-fluoroanilide derivatives in moderate to good yields. Selectfluor (TM) serves the dual purpose of fluorine source and assists 1,3-carbonyl migration. The formation of proposed charge transfer (CT) complex between ortho-carbonyl aniline (donor) and selectfluor (TM) (acceptor), and its role in enabling the observed ortho-selectivity is supported by experimental and computational investigations. The single-electron-transfer (SET) in the complex results in the formation of (2-amino-3-fluorophenyl)(phenyl)methanone intermediate, which on subsequent 1,3-carbonyl migration forms ortho-fluoroanilide in presence of F+ or in-situ generated H+.