Photoredox-Catalyzed Cascade Difluoroalkylation and Intramolecular Cyclization for Construction of Fluorinated γ‑Butyrolactones

A cascade
visible-light photocatalytic difluoroalkylation and intramolecular
cyclization reaction has been developed for the synthesis of difluoroalkylated
oxygen heterocycles. The reaction was carried out under very mild
conditions, affording fluorinated isobenzofuran-1-ones, lactone, and
cyclic ethers with up to 97% chemical yields. Furthermore, several
types of bromofluoroalkane precursors bearing ester, keto, amido,
and phosphate groups could all work very well in this reaction, which
provides an easy method for the preparation of functionalized difluoroalkylated
oxygen heterocycles.