MONO ET DIFLUORATION ELECTROCHIMIQUES DE GROUPES BENZYLIQUES

Article abstract of DOI:10.1016/S0040-4020(01)89079-7

Anodic oxidation of benzylic compounds 1 using CH3CN as a solvent and Et3N,3HF as a fluorinating reagent allowed to introduce a fluorine atom in α position of electron withdrawing group via carbocation 1+ (EC_BEC_N mechanism).Whatever the E group, monofluorides 2 are obtained in good yields from paramethoxy derivatives 1 (R=p-OCH3).In this case, by raising the potential of working electrode after the monofluorination step, gem difluorides 3 can be directly prepared from 1.When the substituent of the phenyl ring is different of a methoxy group, a mixture of fluoride 2 and acetamide 4 is generally obtained and the ratio of these two compounds is related to cation stability.