Enantioselective [4+2] cycloaddition reaction of α,β-unsaturated imine and methyl vinyl ketone catalyzed by chiral phosphine

Abstract New bifunctional phosphines were prepared as chiral organocatalysts for the enantioselective [4+2] cycloaddition between α,β-unsaturated imines and methyl vinyl ketone. In the presence of 10 mol % of amide-phosphine, the [4+2] cycloaddition reaction was achieved in good-to-excellent yields (up to 95%) and diastereoselectivities (up to 99:1 dr ) with moderate-to-good enantioselectivities (up to 82% ee ). This methodology establishes a new protocol for the asymmetric construction of functionalized tetrahydropyridines.