Reactions of Difluorocarbene with Organozinc Reagents

Reactions of difluorocarbene with benzyl and alkylzinc halides leading to fluorinated organozinc species have been described. The generated α-difluorinated organozinc reagents are reasonably stable in solution and can be quenched with external electrophiles (iodine, bromine, proton), affording compounds containing the CF₂ fragment

Nucleophilic Difluoromethylation Using (Bromo­difluoro­methyl)­trimethyl­silane

A combination of (bromodifluoro­methyl)­trimethyl­silane (Me₃SiCF₂Br), triphenyl­phosphine, and DMPU serves as a source of difluorinated phosphorus ylide Ph₃PCF₂ under mild conditions. The system was used to effect nucleophilic difluoromethylation of ketones and nitro alkenes. The reaction efficiency is believed to be associated with Lewis acidic activation of the substrates by a silylium species formed upon generation of the phosphorus ylide

Difluoromethylene Phosphabetaine as an Equivalent of Difluoromethyl Carbanion

A method for nucleophilic difluoromethylation of reactive Michael acceptors, aldehydes, and azomethines is described. The reaction is performed using the readily available and air-stable reagent difluoromethylene phosphabetaine. The process involves interaction of an electrophilic substrate with in situ generated difluorinated phosphonium ylide followed by hydrolysis of the carbon–phosphorus bond under mild conditions

Geminal Silicon/Zinc Reagent as an Equivalent of Difluoromethylene Bis-carbanion

A new difluorinated reagent, [difluoro­(trimethylsilyl)­methyl]­zinc bromide, bearing C–Zn and C–Si bonds is described. The reagent is conveniently prepared by cobalt-catalyzed halogen/zinc exchange. It can be coupled with two different C-electrophiles in a stepwise manner (with allylic halides for C–Zn bond and aldehydes for C–Si bond) affording products containing a difluoromethylene fragment