phosphonite

A phosphonite is a functional group or compound containing a phosphorus atom bonded to one alkyl or aryl group and two alkoxy or aryloxy groups. The general formula for phosphonites can be represented as P(OR)2R', where R is an organic group and R' is also an organic group. Phosphonites are a class of organophosphorus compounds. They are related to phosphites, which have the general formula P(OR)3, and phosphinates, which have the general formula P(O)(OR)R'2. Phosphonites themselves do not contain a phosphorus-oxygen double bond; this distinguishes them from phosphonates and phosphinates.

These compounds can be synthesized through various methods, often involving the reaction of phosphorus trihalides with alcohols or phenols, followed by reaction with organometallic reagents or Grignard reagents. For example, the reaction of phosphorus trichloride with an alcohol followed by treatment with a Grignard reagent can yield a phosphonite. Phosphonites are typically liquids or solids at room temperature and can be sensitive to oxidation and hydrolysis. Their reactivity is often exploited in organic synthesis, particularly as ligands in transition metal catalysis and as intermediates in the synthesis of other organophosphorus compounds. The P-C bond in phosphonites is generally stable, but the P-O bonds can be cleaved under certain conditions.