Electrochemical fluorination of aliphatic aldehydes and cyclic ketones using Et3N-5HF electrolyte

The Influence of Fluoride Media and CH3CN on the Voltammetric Behavior of Ferrocene, Quinhydrone, and Methyl Phenyl Sulfide on Pt and Carbon Electrodes

“…This type of processes may probably be responsible for the difference in the properties of tetraethylammonium¯uorides [20,21] and triethylammonium¯uorides [18,19]. The anodic peak potential for ferrocene in TEA.3HF=CH 3 CN medium is shifted in the negative direction by around 60 mV on all the three electrodes (Table 1).…”

“…In pyridinium-HF medium, substantially higher oxidation of electrode surface as well as direct oxidation of pyridine were noticed when pyridine content exceeded 5 % [17]. In triethylamine-3HF [18], triethylamine-5HF [19], and tetraalkylammonium¯uoride media, considerably higher background currents are noticed. However, distinct voltammetric responses could be obtained for organic compounds when higher reactant concentrations are employed [18±21].…”

Elektrifizierung der organischen Synthese

“…Therefore,the substrate scope could be broadened by using the neat ionic liquid containing 4o r5equiv of HF. [19] Furthermore,t he fluoride salt can tune the selectivity of the reaction (e.g., a-fluorination vs.f luorodesulfurization) as ar esult of different amounts of free amine base present in the electrolyte.The selectivity can also be tuned by changing the solvent system and thus stabilizing or destabilizing the initially formed radical cations (Scheme 1). [20,21] Initially,e lectrochemical fluorination was performed in aprotic solvents.However, significant anode passivation and, in the case of CH 3 CN,c oncurring acetamidation were observed.…”

Electrolytic Reactions

“…However, such film formation is reduced considerably when the new supporting fluoride salts are used. Yoneda and Fukuhara also investigated the electrochemical stability (potential window) of ionic liquid Et 3 N ÁnHF (n ¼ 3-5) by cyclic voltammetry [23]. Their anodic stability increases with an increase of HF content (n) in the fluoride salts while the cathodic stability shows the reverse tendency.…”

“…The potential window of Et 4 NF Á4HF is almost same as that of Et 3 N Á5HF, as shown in Figure 8.5. Thus the selective anodic fluorination of cyclic ketones and cyclic unsaturated esters in Et 3 N Á5HF was successfully carried out to provide ring-opening and ring-expansion fluorinated products, respectively, as shown in Schemes 8.7 and 8.8 [23,24].…”