Hypervalent λ3-Fluoro Iodane Triggered Semipinacol Rearrange-ments: Efficient Synthesis of Quaternary α-Fluoro Ketones

Hypervalent λ3-fluoro iodanes have emerged as versatile reagents, providing unusual fluorination selectivities under mild reac-tion conditions. Here, we report on adding a semipinacol rearrangement to the fluorination, aryl migration cascade reaction of styrene derivatives. Thus, various cyclopentanones became accessible in up to 96% yield all bearing quaternary C,F-carbon center adjacent to the ketone group. Such fluorinated structural motifs are difficult to build with previously established meth-ods. Preliminary experiments on enantioselective processes validated that asymmetric transformations are likewise feasible.