N-Fluoropyridinium Salts Radical Fluorination for Preparing Alkyl Fluorides

Introduction

N-Fluoropyridinium salts with different fluorination power are well known as quite effective electrophilic fluorinating reagents which can introduce fluorine into various nucleophilic substrates as described in the chapters “N-Fluoropyridinium Salt Electrophilic Fluorination for Preparing Alkyl Fluorides” and “N-Fluoropyridinium Salt Fluorination for Preparing Aryl Fluorides” [1,2,3,4]. In many cases, mechanistic aspect was explained by the single electron transfer from the nucleophilic substrate to the electrophilic N-fluoropyridinium salt followed by the homolytic cleavage of N–F bond to generate fluorine radical and the radical or radical cation species of the substrate, which then combine each other to give the fluorinated product [3].

Recently, as a new radical fluorination, a cobalt-catalyzed hydrofluorination reaction of unactivated olefins with N-fluoropyridinium salt, was reported. As shown in Scheme 1, it was proposed that this reaction involved the carbon...