Phosphine-catalyzed γ-addition of nitroacetates to allenoates for enantioselective creation of α,α-disubstituted α-amino acid precursors

Abstract

Enantioselective γ-addition of readily available α-substituted nitroacetates to allenoates has been achieved. This protocol provides a straightforward asymmetric synthesis of optically enriched α,α-disubstituted α-amino acid precursors, a class of molecular architectures that are of great importance in biological sciences. In the presence of amino acid-derived phosphine catalysts, the γ-addition proceeded efficiently, forming products containing a tetra-substituted stereogenic center in high yields with good to excellent enantioselectivities.