The first highly enantioselective aminocatalytic activation of α-substituted α,β-unsaturated aldehydes is presented. The chiral primary amine 1 selectively activates α-branched enals toward a well-defined iminium ion/enamine reaction sequence for both Friedel-Crafts/amination and sulfa-Michael/amination cascades. The valuable multifunctional products, having two contiguous sterocenters, are isolated in high enantiomeric purity.
Asymmetric organocatalytic cascade reactions with α-substituted α,β-unsaturated aldehydes
Angew. Chem. Int. Ed. 2009, 48, 7892-7894.
Highlighted in Synfact 2009, 1278