Nickel-Catalyzed Homologation of Vinylidene Difluoride (CH2=CF2): Selective beta-F vs beta-H Elimination

Hydrofluoroolefins (HFOs) constitute the newest generation of fluorocarbon refrigerants and foam-blowing agents due to their reduced global warming potential vs their saturated analogues. To identify new synthetic routes to HFOs, we show that reactions of bulky Ni(0) phosphine and -NHC complexes with vinylidene difluoride (VF2) afford mu-fluoro-1,1,3-trifluorobut-3-enyl Ni complexes. Moreover, addition of triisopropylsilane allows for reductive elimination of the reduced product-2,4,4-trifluoro-1-butene-demonstrating the Ni-catalyzed hydrodefluorodimerization of VF2. Accompanying DFT calculations identify the Tshaped nickelacyclopentane intermediate that spontaneously undergoes selective intramolecular beta-F (vs beta-H) elimination.

Automated summary

In this study, bulky metal catalysts were used to react with vinylidene difluoride, resulting in the synthesis of a new type of HFO compound, with the reaction mechanism identified through calculations.