Nonsilyl bicyclic secondary amine catalyzed Michael addition of nitromethane to β,β-disubstituted α,β-unsaturated aldehydes

The asymmetric Michael addition of nitroalkanes to β,β-disubstituted α,β-unsaturated aldehydes is a useful method for the construction of all-carbon quaternary stereocenters. Nonsilyl bicyclic secondary amine organocatalysts were employed in reactions involving a wide range of β,β-disubstituted α,β-unsaturated aldehydes with nitroalkanes to achieve products with all-carbon quaternary stereocenters in up to 69% yield and 95% ee. The scalability of this methodology was demonstrated at the 5.1 mmol scale. The synthetic utility of this methodology is showcased through the concise asymmetric synthesis of methsuximide, an anticonvulsant drug.