In chemistry, phosphorochloridites are a class of organophosphorus compound with the formula (RO)<sub>2</sub>PCl (R = organic substituent). They are pyramidal in shape, akin to regular phosphites (P(OR)<sub>3</sub>). They are usually colorless and sensitive toward hydrolysis and, to some extent, oxidation to the corresponding phosphorochloridates ((RO)<sub>2</sub>P(O)Cl).
Phosphorochloridites are produced by partial alcoholysis of phosphorus trichloride, which proceeds stepwise:
These reactions are readily controlled with aromatic diols, such as binaphthol and 2,2'-biphenol.
Phosphorochloridites are precursors to diphosphite ligands. When combined with rhodium precursors such as Rh(acac)(CO)<sub>2</sub>, these diphosphite ligands afford catalysts that are used industrially for the hydroformylation of alkenes. it and related ligands have become popular in hydroformylation catalysis.