Phosphinites are organophosphorus compounds with the formula P(OR)R2. They are used as ligands in homogeneous catalysis and coordination chemistry.[1]

Structural formula of a generic phosphinite, R represents a side chain.
Skeletal formula of methyl diphenylphosphinite


Phosphinites are prepared by alcoholysis of organophosphinous chlorides. For example, treatment of chlorodiphenylphosphine with methanol and base gives methyl diphenylphosphinite:

ClPPh2 + CH3OH → CH3OPPh2 + HCl

Although they are esters of phosphinous acids (R2POH), phosphinites are not made via such intermediates.


Oxidation of phosphinites gives phosphinates:

2 P(OR)R2 + O2 → 2 OP(OR)R2

Phosphinites are ligands, giving derivatives similar to metal phosphine complexes. They are stronger pi-acceptors than typical phosphine ligands.[2]


  1. ^ D. E. C. Corbridge (1995). Phosphorus: An Outline of its Chemistry, Biochemistry, and Technology (5th ed.). Amsterdam: Elsevier. ISBN 0-444-89307-5.
  2. ^ Rajanbabu, T. V. Babu (2012). "Phosphinite and Phosphonite Ligands". Phosphorus(III) Ligands in Homogeneous Catalysis: Design and Synthesis. pp. 159–232. doi:10.1002/9781118299715.ch5. ISBN 9781118299715.

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