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  • Co-Catalyzed Hydrofluorination of Alkenes: Photocatalytic Method Development and Electroanalytical Mechanistic Investigation
Title: Co-Catalyzed Hydrofluorination of Alkenes: Photocatalytic Method Development and Electroanalytical Mechanistic Investigation
The hydrofluorination of alkenes represents an attractive strategy for the synthesis of aliphatic fluorides. This approach provides a direct means to form C(sp3)–F bonds selectively from readily available alkenes. Nonetheless, conducting hydrofluorination using nucleophilic fluorine sources poses significant challenges due to the low acidity and high toxicity associated with HF and poor nucleophilicity of fluoride. In this study, we present a new Co(salen)-catalyzed hydrofluorination of simple alkenes, utilizing Et3N·3HF as the sole source of both hydrogen and fluorine. This process operates via a polar- radical-polar crossover mechanism. We also demonstrated the versatility of this method by effectively converting a diverse array of simple and activated alkenes with varying degrees of substitution into hydrofluorinated products. Furthermore, we successfully applied this methodology to 18F-hydrofluorination reactions, enabling the introduction of 18F into potential radi- opharmaceuticals. Our mechanistic investigations, conducted using rotating disk electrode voltammetry and DFT calcula- tions, unveiled the involvement of both carbocation and CoIV–alkyl species as viable intermediates during the fluorination step, and the contribution of each pathway depends on the structure of the starting alkene.  more » « less
Award ID(s):
2055451
PAR ID:
10540449
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
American Chemical Society
Date Published:
Journal Name:
Journal of the American Chemical Society
Volume:
146
Issue:
7
ISSN:
0002-7863
Page Range / eLocation ID:
4380 to 4392
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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