Molecular Design, Synthesis, and Asymmetric Catalysis of a Hexacoordinated Chiral Phosphate Ion

We describe the design, synthesis,
and characterization of a chiral
hexacoordinated phosphate ion that features an octahedral P­(V) core
consisting of two N,N,O-tridentate backbones. We further demonstrate that the corresponding
hydrogen phosphate acts as an effective catalyst for a highly enantioselective
Pictet–Spengler-type reaction, wherein the relationship between
the structure of the chiral phosphate ion and its ability to dictate
the absolute stereochemistry is revealed in conjunction with precise
structural elucidation of the phosphate ion.