Asymmetric synthesis of β-phosphono malonates via Fe2O3-mediated phospha-Michael addition to knoevenagel acceptors

[GRAPHICS] The first asymmetric P-C bond formation under heterogeneous conditions was achieved via a Fe2O3-mediated conjugate addition of a chiral phosphite to alkylidene malonates. The easy cleavage of the chiral auxiliary from the addition products leads to optically active beta -substituted, beta -phosphono malonates in good yields and high enantiomeric excesses.