Difluoromethylating Reagents

Difluoromethylated compounds have been widely used as building blocks for pharmaceuticals or agrochemicals, thus, various kinds of difluoromethylating reagents have been developed. For example, difluoromethyl phenyl sulfone (1), a difluoromethyl anion equivalent, reacts with primary alkyl halides to afford the corresponding difluoromethylated products through a nucleophilic substitution – reductive desulfonylation.¹⁾

Moreover, the difluoromethylation methods using diethyl (bromodifluoromethyl)phosphonate (2) or trimethylsilyl difluoro(fluorosulfonyl)acetate (3) as difluorocarbene (:CF₂) precursors also have been reported.　　2 and 3 generate :CF₂ in the presence of KOH and NHC catalysts, respectively, to afford the corresponding aryl difluoromethyl ethers.