A General, Scalable, Organocatalytic Nitro-Michael Addition to Enones: Enantioselective Access to All-Carbon Quaternary Stereocenters

A tert-leucine-derived chiral diamine catalyzes
the asymmetric Michael addition of nitromethane to five-, six-, and
seven-membered β-substituted cyclic enones with excellent enantioselectivity,
offering scalable, asymmetric access to all-carbon quaternary stereocenters.
The reaction scope can be expanded to include linear acyclic enones,
and excellent levels of enantioselectivity are also observed. Furthermore,
this organocatalytic, asymmetric nitro-Michael reaction is amenable
to multigram scale-up and applications in the construction of an eudesmane
sesquiterpenoid skeleton.