Electrolytic partial fluorination of organic compounds. Part 60: Highly regioselective anodic fluorination of aryl propargyl sulfides

Aryl propargyl sulfides were subjected to electrochemical fluorination in dimethoxyethane (DME) containing various fluoride supporting electrolytes using an undivided cell to provide the corresponding alpha-monofluorinated or alpha,alpha-difluorinated sulfides selectively as main products in good yields depending on the amount of electricity passed. The alpha,alpha-difluorinated sulfides were stable enough to be isolated while the alpha-monofluorinated ones were very unstable. The alpha-monofluorinated sulfides were readily converted into the corresponding stable alpha-monofluoroallenyl sulfides in good yields. Furthermore, synthetic utility of alpha-monofluoroallenyl sulfides was also investigated. (C) 2002 Elsevier Science Ltd. All fights reserved.