Catalytic Asymmetric Synthesis of α,β-Disubstituted α,γ-Diaminophosphonic Acid Precursors by Michael Addition of α-Substituted Nitrophosphonates to Nitroolefins
various nitroolefins are shown to proceed with high diastereo- and enantioselectivity when catalyzed by a quinine-derived thiourea-tertiary amine bifunctional catalyst and generate α,γ-diaminophosphonic acidprecursors with contiguous quaternary and tertiary stereocenters.