Phosphorochloridite
# Phosphorochloridite

In chemistry, phosphorochloridites are a class of organophosphorus compound with the formula $(RO)_2PCl$ (R = organic substituent). They are pyramidal in shape, akin to regular phosphites $(P(OR)_3).$ They are usually colorless and sensitive toward hydrolysis and, to some extent, oxidation to the corresponding phosphorochloridates $((RO)_2P(O)Cl).$

## Synthesis and reactions

Phosphorochloridites are produced by partial alcoholysis of phosphorus trichloride, which proceeds stepwise:

    $PCl_3$ + ROH → HCl + $(RO)PCl_2$ (phosphochloridite)
    $(RO)PCl_2$ + ROH → HCl + $(RO)_2PCl$ (phosphodichloridite)
    $(RO)_2PCl$ + ROH → HCl + $(RO)_3P$ (phosphite)

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 $Rh(acac)(CO)_2,$ these diphosphite ligands afford catalysts that are used industrially for the hydroformylation of alkenes. it and related ligands have become popular in hydroformylation catalysis.

