Selective anodic fluorination of electrophilic alkenes

3D Printed Reactionware for Synthetic Electrochemistry with Hydrogen Fluoride Reagents

“…These organic basic HF sources are readily soluble in organic solvent, and these solutions are sufficiently conductive that supporting electrolyte is often not required due to their (partial) ionic nature. Thus, the combination of anodic oxidation and hydrogen fluoride has been used for the fluorination of alkenes, [7,[17][18][19][20][21][22][23][24][25] alkynes, [18] aromatic rings, [26][27][28][29] esters, [30][31][32] ketones [16,33] and thioketals, [34][35][36][37][38] among others, Figure 1A. Warning: Extreme care should always still be used in handling these materials; handle only in a fume hood, wear safety goggles or a face shield, and wear appropriate impermeable clothing.…”

Electrochemical strategies for C–H functionalization and C–N bond formation

“…334,335 Moreover, regioselective electrochemical monofluorination has also been reported for a collection of oxygen-containing heterocycles, including carbonates, 336,337 chroman-4-ones, [338][339][340] esters, 337 ethers 336,337 and lactones. 336,337 Additionally, electrochemical protocols for accomplishing fluorodesulfurization, [341][342][343][344][345][346][347][348][349] difluorination, 350,351 fluoro-selenylation, 352 iodofluorination 353 and thiofluorination 354 of electron-deficient olefins as well as partial fluorination of conjugated dienes 355 have been devised. 356 In contrast to the electrochemical fluorination strategies, the anodic oxidation protocols involving chlorides, bromides and iodides typically proceed via generation of the corresponding electrophilic molecular counterpart (X 2 ) due to the relatively low oxidation potentials of these halogen ions.…”

Renewable Electricity Enables Green Routes to Fine Chemicals and Pharmaceuticals

“…Another thought‐provoking research topic is asymmetric electro‐carboxylation via CO 2 [116–188] . The notable point is that, in the production of new chiral centres, both the carbon and oxygen atoms of CO 2 might be involved.…”

“…These organic HF sources are readily soluble in organic solvents, and so the need for supporting electrolytes is eliminated since these solutions are appropriately conductive due to their ionic nature. As for the fluorination of aromatic rings, [169][170][171][172] alkenes, [173][174][175][176][177][178][179] alkynes, [180] esters, [181][182][183] thioketals [184][185][186][187][188] and ketones, [189] the combination of HF and anodic oxidation has been successfully employed. However, Lennox et al reported the electrochemical cells that has been 3D printed and it is a cost effective, facile technique, efficient to handle the harsh reaction conditions integral in the use of HF in organic reactions.…”

“…The electrochemical partial fluorination (ECPF) of some electrophilic alkenes (alkenes conjugated with electron withdrawing species) may take place via anodic fluorination, using such precursors as cinnamonitrile, α,β-unsaturated ketones (phenyl 3,5-di-t-butyl-4-hydroxystyryl ketone, phenyl styryl ketone and t-butyl styryl ketones) and α,β-unsaturated esters (ethyl cinnamates), as reported by Andrés, Dinoiu and coworkers. [192,193] The fluorine sources and supporting electrolytes used in these reactions were Et 4 NF • nHF (n = 2,4) and Et 3 N • nHF (n = 3,5), respectively, and CH 2 CI 2 was used as electrolytic solvent. An attractive fluorination took place once phenyl 3,5-di-t-butyl-hydroxystyryl ketones (a chalcone) 62 experienced anodic fluorination using Et 4 NF • 2HF as both supporting electrolyte and fluorine source, while CH 2 CI 2 was employed as an electrolytic solvent, which lead to the formation of two monofluoro adducts 63 and 64, each in 30 % yield in a 1 : 1 ratio.…”