Catalytic Asymmetric Hydrophosphination of α,β-Unsaturated Aza-heteroarenes

Here we report a comprehensive investigation of the asymmetric addition of diarylphosphorus oxides to a wide range of α,β-unsaturated pyridines and other N-heterocyclic substrates, catalyzed by commercial chiral phosphoric acid, affording the corresponding products in up to 99% yield and 96% ee. The experimental studies and density functional theory calculation suggest the possible mechanism and the role of chiral phosphoric acid in the control of enantioselectivity.