In
organophosphorus chemistry
Organophosphorus compounds are organic compounds containing phosphorus. They are used primarily in pest control as an alternative to chlorinated hydrocarbons that persist in the environment. Some organophosphorus compounds are highly effective ins ...
, the Pudovik reaction is a method for preparing
α-aminomethylphosphonates. Under basic conditions, the phosphorus–hydrogen bond of a
dialkylphosphite, (RO)
2P(O)H,
adds across the carbon–nitrogen double bond of an
imine
In organic chemistry, an imine ( or ) is a functional group or organic compound containing a carbon–nitrogen double bond (). The nitrogen atom can be attached to a hydrogen or an organic group (R). The carbon atom has two additional single bo ...
(a
hydrophosphonylation reaction). The reaction is closely related to the three-component
Kabachnik–Fields reaction In organophosphorus chemistry, the Kabachnik–Fields reaction is a three-component organic reaction forming aminophosphonate, α-aminomethylphosphonates from an amine, a carbonyl compound, and a phosphite ester, dialkyl phosphonate, (RO)2P(O)H (tha ...
, where an
amine
In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituen ...
, phosphite, and an organic
carbonyl compound
In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups. A compound containing a ...
are condensed, which was reported independently by Martin Kabachnik and Ellis Fields in 1952. In the Pudovik reaction, a generic imine, RCH=NR', would react with a phosphorous reagent like
diethylphosphite
Diethylphosphite is the organophosphorus compound with the formula (C2H5O)2P(O)H. It is a popular reagent for generating other organophosphorus compounds, exploiting the high reactivity of the P-H bond. Diethylphosphite is a colorless liquid. The ...
as follows:
:RCH=NR' + (EtO)
2P(O)H → (EtO)
2P(O)CHR-NHR'
In addition to the Lewis-acid catalyzed Pudovik reaction, the reaction may be carried out in the presence of chiral amine bases. Catalytic amounts of
quinine
Quinine is a medication used to treat malaria and babesiosis. This includes the treatment of malaria due to ''Plasmodium falciparum'' that is resistant to chloroquine when artesunate is not available. While sometimes used for nocturnal leg cr ...
, for instance, promote the enantioselective Pudovik reaction of aryl aldehydes.
Catalytic, enantioselective variants of the Pudovik reaction have been developed.
References
{{reflist, 35em
Name reactions