2,2-Difluoro-1,3-diketones as gem-Difluoroenolate Precusors for Asymmetric Aldol Addition with N-Benzylisatins

2,2-Difluoro-1,3-diketones are introduced as gem-difluoroenolate precursors for the first example of an organocatalytic asymmetric aldol addition with N-benzylisatins to form 3-difluoroalkyl-3-hydroxyoxindoles.