Asymmetric Transfer\nHydrogenation of <i>gem</i>-Difluorocyclopropenyl Ketones:\nThe Synthesis and Functionalization\nof Enantioenriched <i>cis gem</i>-Difluorocyclopropyl Ketones

The\nasymmetric transfer hydrogenation of <i>gem</i>-difluorocyclopropenyl\nketones, catalyzed by a Noyori–Ikariya ruthenium complex, was\ndeveloped to access substituted optically enriched <i>cis</i>-disubstituted <i>gem</i>-difluorocyclopropyl ketones,\nand the value of these latter building blocks was illustrated by the\nsynthesis of heterocycles fused to the difluorocyclopropyl moiety.