Highly enantioselective Simmons-Smith fluorocyclopropanation of allylic alcohols via the halogen scrambling strategy of zinc carbenoids.

Highly enantio- and diastereoenriched monofluorocyclopropanes were accessed via the Simmons-Smith fluorocyclopropanation of allylic alcohols using difluoroiodomethane and ethylzinc iodide as the substituted carbenoid precursors. The scrambling of halogens at the zinc carbenoid led to the formation of the fluorocyclopropanating agent (fluoroiodomethyl)zinc(II) fluoride. This strategy circumvented the ongoing limitation in Simmons-Smith fluorocyclopropanations relying on the use of the relatively inaccessible and expensive carbenoid precursor fluorodiiodomethane.