Dual Non-C1 Synthon Role of CO2 in Controlled Electrochemical Defluorination.

The dual role of carbon dioxide (CO2) as a non-C1 synthon in controlled electrochemical defluorination has been exploited to produce monofluorinated or difluorinated products. In defluorination, CO2 may fulfill two functions. First, serving as an electron-electron transfer mediator, it expedites the initial one-electron reduction. Second, acting as an electrophilic reagent, it reacts with the radical anion, diminishing its reduction potential and consequently facilitating the second one-electron reduction.