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.