A Sc(OTf)₃ catalyzed Mukaiyama-Mannich reaction of difluoroenoxysilanes with unactivated ketimines

An efficient Mukaiyama-Mannich reaction of difluoroenoxysilanes with unactivated ketimines enabled by 5 mol% of Sc(OTf)₃ is reported here. This protocol provides expedient access to a series of α,α-difluoro-β-amino ketones possessing a tetrasubstituted carbon center in moderate to high yields (up to 89% yield). Moreover, the Mannich adducts could be easily converted into diversified gem-difluorinated compounds.