Mild Silver‐Mediated Geminal Difluorination of Styrenes Using an Air‐ and Moisture‐Stable Fluoroiodane Reagent

Abstract

An air-and moisture-stable fluoroiodane in the presence of AgBF 4 is suitable for selective geminal difluorination of styrenes under mild reaction conditions. One of the CÀF bonds is formed by transfer of electrophilic fluorine from the hypervalent iodine reagent, while the other one arises from the tetrafluoroborate counterion of silver. Deuterium-isotopelabelling experiments and rearrangement of methyl styrene substrates suggest that the reaction proceeds through a phenonium ion intermediate.

A Versatile Organocatalytic Approach for the Synthesis of Enantioenriched gem‐Difluorinated Compounds

“…Hypervalent iodine reagents have also been employed for the gem-difluorinationo fs tyrenes and dicarbonylc ompounds. [10] It is also worth mentioningt hat ad irect selectives ynthesiso f gem-difluorinated nitrogen-containingb uilding blocks in superacid media was reported. [11] The dramaticr ole of the chlorine atom in the reaction is shown by NMR experiments in situ and allows the involvement of an ovel superelectrophilic activationp rocess in superacid HF/SbF 5 to be postulated.…”

Nickel‐Catalyzed Reductive Cross‐Coupling of (Hetero)aryl Halides with 2‐Chloro‐1,1‐difluoroethane: Facile Access to 2,2‐Difluoroethylated Aromatics

“…One is nucleophilic fluorination of benzylic aldehydes and their derivatives, [6] or fluorination of styrenes derivatives via a λ 3iodane species. [7] However, the harsh reaction conditions limits the late-stage fluorination of complex molecules. Alternatively, the introduction of CF 2 H to benzylic compounds, [8] or direct incorporation of CH 2 CF 2 H into aromatic ring [9] is an attractive strategy for synthesis of such compounds via the formation of CÀ C bonds.…”