Electrolytic partial fluorination of organic compounds. Part 34. Regioselective anodic fluorination of benzyl thiocyanate and its derivatives

Electrochemical partial fluorination of organic compounds: 81. Regioselective anodic fluorination of O-methyl S-aralkyl thiocarbonates

“…Their oxidation potentials together with the oxidation potentials of benzyl acetate (6) [15] and benzyl thioacetate (7) [15] are listed in Fig. 1.…”

“…These facts suggest that the initial electron-transfer of 1a-1c may take place at the sulfur atom instead of the benzene ring although it is known that the initial oxidation of 4, 6, and 7 occurs at the benzene ring [15].…”

“…We also successfully carried out anodic a-fluorination of benzyl thiocyanates and benzyl acetate (Scheme 3) and it was disclosed that the initial electron-transfer takes place at the benzene ring instead of the thiocyanate and acetate moieties [15].…”

The selective electrochemical fluorination of S-alkyl benzothioate and its derivatives

“…On the other hand, Simonet and co-workers reported the anodic fluorination of alkyl phenyl sulfides having an EWG on the phenyl group in Et 3 N·3HF/MeCN to provide α-monofluorinated products in moderate yields [ 20 ]. We also achieved the anodic fluorination of benzyl and ethyl thiocyanates as well as O -methyl S -aralkyl thiocarbonates by using the anodically stable Et 3 N·5HF and Et 4 NF·4HF [ 21 – 22 ]. In both cases, an EWG attached to the phenyl group and the electron-withdrawing SCN group both contribute to the generation of the cation resulting in a regioselective α-fluorination.…”

Electrolytic fluorination of organic compounds

“…Benzyl thiocyanates. Benzyl thiocyanates 72 were also fluorinated, using Et 4 NF·4HF, at the benzylic carbon to give the corresponding a-fluorothiocyanates 73 in moderate yields (Scheme 23) 65. …”