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.
Keywords:
Diamines
,Sesquiterpenes, Eudesmane
,Ketones
,Nitro Compounds
,Leucine
,Valine
,Molecular Structure
,Catalysis
,Stereoisomerism