A phosphite ester or organophosphite is a type of chemical compound

Chemical compound

A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

 with the general structure P(OR)₃. Phosphite esters can be considered as ester

Ester

Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...

s of phosphorous acid

Phosphorous acid

Phosphorous acid is the compound described by the formula H3PO3. This acid is diprotic , not triprotic as might be suggested by this formula. Phosphorous acid is as an intermediate in the preparation of other phosphorus compounds.-Nomenclature and tautomerism:H3PO3 is more clearly described with...

, H₃PO₃. A simple phosphite ester is trimethylphosphite, P(OCH₃)₃. Phosphite esters can be prepared by reacting phosphorus trichloride

Phosphorus trichloride

Phosphorus trichloride is a chemical compound of phosphorus and chlorine, having chemical formula PCl3. Its shape is trigonal pyramidal. It is the most important of the three phosphorus chlorides. It is an important industrial chemical, being used for the manufacture of organophosphorus compounds...

 or phosphorus tribromide

Phosphorus tribromide

Phosphorus tribromide is a colourless liquid with the formula PBr3. It fumes in air due to hydrolysis and has a penetrating odour. It is widely used in the laboratory for the conversion of alcohols to alkyl bromides.-Preparation:...

 with an alcohol

Alcohol

In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....

 and a tertiary amine.

Phosphite esters are used in the Perkow reaction

Perkow reaction

The Perkow reaction is an organic reaction in which a trialkyl phosphite ester reacts with a haloketone to form a dialkyl vinyl phosphate and an alkyl halide....

 in the formation of vinyl phosphonates and in the Michaelis–Arbuzov reaction to form phosphonate

Phosphonate

Phosphonates or phosphonic acids are organic compounds containing C-PO2 or C-PO2 groups . Bisphosphonates were first synthesized in 1897 by Von Baeyer and Hofmann. An example of such a bisphosphonate is HEDP . Since the work of Schwarzenbach in 1949, phosphonic acids are known as effective...

s. One other particular use is that of reducing agent

Reducing agent

A reducing agent is the element or compound in a reduction-oxidation reaction that donates an electron to another species; however, since the reducer loses an electron we say it is "oxidized"...

. For example triethylphosphite is known to reduce certain hydroperoxides to alcohols formed by autoxidation

Autoxidation

Autoxidation is any oxidation that occurs in open air or in presence of oxygen and/or UV radiation and forms peroxides and hydroperoxides. A classic example of autoxidation is that of simple ethers like diethyl ether, whose peroxides can be dangerously explosive. It can be considered to be a slow,...

 (scheme 1). In this process the phosphite is converted to a phosphate ester.

This reaction type is also utilized in the Wender Taxol total synthesis

Wender Taxol total synthesis

The Wender Taxol total synthesis in organic chemistry describes a Taxol total synthesis by the group of Paul A. Wender at Stanford University published in 1997. This synthesis has much in common with the Holton Taxol total synthesis in that it is a linear synthesis starting from a naturally...

.

The compound trimethylolpropane phosphite

Trimethylolpropane phosphite

Trimethylolpropane phosphite, C2H5C3P, is a phosphite ester used as a ligand in organometallic chemistry. Trimethylolpropane phosphite is sometimes abbreviated to EtCage. Several EtCage complexes have been synthesised and studied to date, including [2Mo4], [Ir411] and RuCl2, shown below....

is a ligand used in organometallic chemistry.