Phosphinite

Not to be confused with phosphonite (formula P(OR)₂R) .

In organic chemistry, 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

Preparation

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.

Reactions

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]