Triethyl phosphite (TEP) is an

organophosphorus compound Organophosphorus chemistry is the scientific study of the synthesis and properties of organophosphorus compounds, which are organic compounds containing phosphorus. They are used primarily in pest control as an alternative to chlorinated hydrocarbo ...

, specifically a

phosphite ester file:Phosphite.svg, The general structure of a phosphite ester showing the lone pairs on the P In organic chemistry, a phosphite ester or organophosphite usually refers to an organophosphorous compound with the formula P(OR)3. They can be conside ...

, with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

P(OCH₂CH₃)₃, often abbreviated P(OEt)₃. It is a colorless, malodorous liquid. It is used as a

ligand In coordination chemistry, a ligand is an ion or molecule with a functional group that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's el ...

organometallic chemistry Organometallic chemistry is the study of organometallic compounds, chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal, including alkali, alkaline earth, and transition metals, and so ...

and as a reagent in

organic synthesis Organic synthesis is a branch of chemical synthesis concerned with the construction of organic compounds. Organic compounds are molecules consisting of combinations of covalently-linked hydrogen, carbon, oxygen, and nitrogen atoms. Within the gen ...

. The molecule features a pyramidal phosphorus(III) center bound to three ethoxide groups. Its ³¹P

NMR Nuclear magnetic resonance (NMR) is a physical phenomenon in which atomic nucleus, nuclei in a strong constant magnetic field are disturbed by a weak oscillating magnetic field (in the near and far field, near field) and respond by producing ...

spectrum features a signal at around +139 ppm vs phosphoric acid standard. Triethylphosphite is prepared by treating

phosphorus trichloride Phosphorus trichloride is an inorganic compound with the chemical formula PCl3. A colorless liquid when pure, it is an important industrial chemical, being used for the manufacture of phosphites and other organophosphorus compounds. It is toxic ...

with

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

in the presence of a base, typically a tertiary amine: :PCl₃ + 3 EtOH + 3 R₃N → P(OEt)₃ + 3 R₃NH + 3 Cl⁻ In the absence of the base, the reaction of ethanol and phosphorus trichloride affords diethylphosphite ((EtO)₂P(O)H). Of the many related compounds can be prepared similarly, triisopropyl phosphite is an example (b.p. 43.5 °C/1.0 mm; CAS# 116-17-6).

Reactions

Triethyl phosphite can react with electrophiles in a

Michaelis–Arbuzov reaction The Michaelis–Arbuzov reaction (also called the Arbuzov reaction) is the chemical reaction of a trivalent phosphorus ester with an alkyl halide to form a pentavalent phosphorus species and another alkyl halide. The picture below shows the most c ...

to produce organophosphonates. For example, the reaction between triethyl phosphite and

ethyl bromoacetate Ethyl bromoacetate is the chemical compound with the formula . It is the ethyl ester of bromoacetic acid and is prepared in two steps from acetic acid. It is a lachrymator and has a fruity, pungent odor. It is also a highly toxic alkylating agen ...

produces a phosphonate suitable for use in the

Horner–Wadsworth–Emmons reaction The Horner–Wadsworth–Emmons (HWE) reaction is a chemical reaction used in organic chemistry of stabilized phosphonate carbanions with aldehydes (or ketones) to produce predominantly E-alkenes. In 1958, Leopold Horner published a modifie ...

Reduction/deoxygenation of

hydroperoxide Hydroperoxides or peroxols are Chemical compound, compounds of the form ROOH, where R stands for any group, typically Organic compound, organic, which contain the hydroperoxy functional group (). Hydroperoxide also refers to the hydroperoxide anio ...

s to the alcohols can also be effected using triethyl phosphite. This approach can be utilized for carbonyl α-hydroxylation by reacting the enolate with oxygen, producing an α-hydroperoxide which can be reduced by triethyl phosphite to the alcohol. A proposed mechanism is shown below. Triethylphosphite_alpha-hydroxylation

Triethyl phosphite can also be used in the Corey–Winter olefin synthesis.

As a ligand

coordination chemistry A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of chemical bond, bound molecules or ions, that are in turn known as ' ...

and

homogeneous catalysis In chemistry, homogeneous catalysis is catalysis where the catalyst is in same phase as reactants, principally by a soluble catalyst in a solution. In contrast, heterogeneous catalysis describes processes where the catalysts and substrate are in d ...

, triethylphosphite finds use as a soft ligand. Its complexes are generally lipophilic and feature metals in low oxidation states. Examples include the colorless complexes FeH₂(P(OEt)₃)₄ and Ni(P(OEt)₃)₄ (m.p. 108 °C).{{cite book , last = Ittel , first = Steven D. , title = Inorganic Syntheses , year = 1990 , chapter = Complexes of Nickel(0) , series =

Inorganic Syntheses ''Inorganic Syntheses'' is a book series which aims to publish "detailed and foolproof" procedures for the synthesis of inorganic compounds.copper(I) iodide Copper(I) iodide is an inorganic compound with the chemical formula . It is also known as cuprous iodide. It is useful in a variety of applications ranging from organic synthesis to cloud seeding. Copper(I) iodide is white, but samples often appe ...

References

External links

Eastman triethyl phosphate (TEP)

WebBook page for C6H15PO3
Organophosphites Ethyl esters Foul-smelling chemicals