Catalytic Asymmetric Diarylphosphine Addition to α‑Diazoesters for the Synthesis of P‑Stereogenic Phosphinates via P*N Bond Formation

The
asymmetric catalytic P–H addition of racemic secondary
phosphines to electrophilic α-diazoesters via P*N bond
formation is disclosed for the first time. Interaction between the
diazoester and the palladium catalyst resulted in the unusually enhanced
electrophilic ability of the terminal nitrogen in the diazo functionality,
as opposed to the commonly expected formation of a metal carbene by
nitrogen elimination. Further derivatization of the generated phosphinic
hydrazones provided access to enantioenriched P-stereogenic diarylphosphinates
via a simple transformation.