Renewable Reagent for Nucleophilic Fluorination
| Autor: | Blaž Alič, Jan Petrovčič, Jan Jelen, Gašper Tavčar, Jernej Iskra |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Journal of organic chemistry, vol. 87, no. 9, pp. 5987-5993, 2022. |
| ISSN: | 1520-6904 0022-3263 |
| DOI: | 10.1021/acs.joc.2c00247 |
| Popis: | Herein, we report a study on the reactivity of three 1,3-diarylimidazolium-based fluoride reagents, with a general formula of [IPrH][F(HF)$_n$] (n = 0, 1, or 2), that tackle the challenges of limited solubility, hygroscopicity, instability, and laborious preparation procedures of nucleophilic fluoride reagents. Fluorination of 4-tert-butylbenzyl bromide reveals that trifluoride [IPrH][F(HF)$_2$] is the most selective reagent. Microwave-assisted activation coupled with the addition of sterically hindered amine DIPEA or alkali metal fluorides increases the rate of fluorination with [IPrH][F(HF)$_2$], making it an excellent reagent for the fluorination of various organic substrates. The scope of substrates includes benzyl bromides, iodides, chlorides, aliphatic halides, tosylates, mesylates, α-haloketones, a silyl chloride, acyl and sulfuryl chlorides, and a nitroarene. The exceptional stability of the air-stable and nonhygroscopic [IPrH][F(HF)$_2$] reagent is illustrated by its convenient synthesis and detailed experimental regeneration protocol using hydrofluoric acid without organic solvents. |
| Databáze: | OpenAIRE |
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