A Chiral Pentafluorinated Isopropyl Group via Iodine(I)/(III) Catalysis
Stephanie Meyer, Joel Häfliger, Michael Schäfer, John J. Molloy, Constantin G. Daniliuc, Ryan Gilmour
Abstract
Abstract An I(I)/(III) catalysis strategy to construct an enantioenriched fluorinated isostere of the i Pr group is reported. The difluorination of readily accessible α‐CF 3 ‐styrenes is enabled by the in situ generation of a chiral ArIF 2 species to forge a stereocentre with the substituents F, CH 2 F and CF 3 (up to 95 %, >20:1 vicinal:geminal difluorination). The replacement of the metabolically labile benzylic proton results in a highly preorganised scaffold as was determined by X‐ray crystallography (π→σ* and stereoelectronic gauche σ→σ* interactions). A process of catalyst editing is disclosed in which preliminary validation of enantioselectivity is placed on a structural foundation.