Related Experiment Video
Updated: Jun 27, 2025

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts
Published on: February 24, 2015
Alkene 1,3-Difluorination via Transient Oxonium Intermediates
Alice C Dean1, E Harvey Randle1, Andrew J D Lacey1
1School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K.
Abstract:
The 1,3-difunctionalization of unactivated alkenes is an under-explored transformation that leads to moieties that are otherwise challenging to prepare. Herein, we report a hypervalent iodine-mediated 1,3-difluorination of homoallylic (aryl) ethers to give unreported 1,3-difluoro-4-oxy groups with moderate to excellent diastereoselectivity. The transformation proceeds through a different mode of reactivity for 1,3-difunctionalization, in which a regioselective addition of fluoride opens a transiently formed oxonium intermediate to rearrange an alkyl chain. The optimized protocol is scalable and shown to proceed well with a variety of functional groups and substitution on the alkenyl chain, hence providing ready access to this fluorinated, conformationally controlled moiety.
More Related Videos
08:43Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives
Published on: January 19, 2016
10:10Application of Elemental Lanthanides in the Selective C-F Activation of Trifluoromethylated Benzofulvenes Providing Access to Various Difluoroalkenes
Published on: July 28, 2018
Related Concept Videos
Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene
Acid-Catalyzed α-Halogenation of Aldehydes and Ketones
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an α-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the –OH group. Consequently, the double bond attacks an electrophilic halogen to form a...
Halogenation of Alkenes
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Hydroboration-Oxidation of Alkenes
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
α-Alkylation of Ketones via Enolate Ions