Primary Amine-Catalyzed Enantioselective Fluorination of α-Branched Aldehydes with Low Catalyst Loadings

β,β-diaryl-β-silyloxy diamines enable catalytic enantioselective fluorination of α-branched aldehydes with a broad substrate scope, even at low catalyst loadings (>90% ee, 1-3 mol %). Furthermore, as a synthetic application, the enantioselective syntheses of fluorine-containing biologically active pharmaceuticals─such as LY50340, α-fluorinated NSAIDs, and α-fluorinated reparixin─were successfully demonstrated. DFT calculations revealed that cumulative steric repulsions among the phenyl groups of NFSI, the enamine, and the catalyst are critical for achieving high enantioselectivity.