S‐((Phenylsulfonyl)difluoromethyl)thiophenium Salts: Carbon‐Selective Electrophilic Difluoromethylation of β‐Ketoesters, β‐Diketones, and Dicyanoalkylidenes

Abstract

S‐((Phenylsulfonyl)difluoromethyl)thiophenium salts were designed and prepared by a triflic acid catalyzed intramolecular cyclization of ortho‐ethynyl aryldifluoromethyl sulfanes. The thiophenium salts were found to be efficient as electrophilic difluoromehtylating reagents for introduction of a CF2H group to sp3‐hybridized carbon nucleophiles such as of β‐ketoesters and dicyanoalkylidenes. The (phenylsulfonyl)difluoromethyl group can be readily transformed into CF2H under mild reaction conditions. Enantioselective electrophilic difluoromethylation was also achieved in the presence of bis(cinchona) alkaloids.

An Iminosemiquinone-Coordinated Oxidovanadium(V) Complex: A Combined Experimental and Computational Study

“…2,2′-Disulfanediyldianiline was synthesized according to a previous report. 10 Solvents were obtained from Merck (India). Mass spectra were measured in a HPLC-grade either acetonitrile or methanol solution.…”

Difluoromethylation of heterocyclesviaa radical process

“…Furthermore, when other types of radical difluoromethylation of heterocycles are concerned, the development of a suitable difluoromethylation reagent and catalytic system plays a crucial role. 87,88 Very recently, Fang and coworkers developed a reliable and efficient difluoromethylation of diverse quinoline and isoquinoline N-oxides via an electrochemical N-orthoselective process (Scheme 23). 89 Sodium difluoromethanesulfinate was chosen as the difluoromethyl source in this strategy, and a variety of N-ortho-selective difluoromethylated quinolines and isoquinoline N-oxides were successfully generated in good to excellent yields.…”