Nickel-catalyzed reductive defluorination of iodo allylic gem-difluorides: allenyl monofluoride synthesis

Abstract

As a potential fluorinated synthon, there have been only limited reports on fluorinated allene synthesis and applications due to concerns about their stability. Here, we developed a nickel-catalyzed reductive defluorination of iodo allyl gem-difluorides to afford allenyl monofluorides under mild conditions with good functional group tolerance, which were easily converted to other C–F bond compounds, such as alkyl and alkenyl fluorides. Preliminary mechanistic studies suggested that monofluoroallenes were yielded by β-F elimination of the alkenyl C–Ni intermediates from the oxidative addition of C–I bonds to a nickel(0) catalyst, while zinc regenerates the catalyst and closes the catalytic cycle.