In organophosphorus chemistry, 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 (a hydrophosphonylation reaction).[1] The reaction is closely related to the three-component Kabachnik–Fields reaction, where an amine, phosphite, and an organic carbonyl compound are condensed,[2] which was reported independently by Martin Kabachnik[3] and Ellis Fields[4] in 1952. In the Pudovik reaction, a generic imine, RCH=NR', would react with a phosphorous reagent like diethylphosphite as follows:[5]

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, for instance, promote the enantioselective Pudovik reaction of aryl aldehydes.[6] Catalytic, enantioselective variants of the Pudovik reaction have been developed.[7]

References

  1. ↑ Engel, Robert (2004). "Phosphorus Addition at sp2 Carbon". Organic Reactions. 36 (2): 175–248. doi:10.1002/0471264180.or036.02. ISBN 0471264180.
  2. ↑ Keglevich, György; Bálint, Erika (2012). "The Kabachnik-Fields reaction: Mechanism and synthetic use". Molecules. 17 (11): 12821–12835. doi:10.3390/molecules171112821. PMC 6268146. PMID 23117425.
  3. ↑ Kabachnik, Martin I.; Medved, T. Ya. (1952). "Новый метод синтеза сс-аминофосфиновых кислот" [A new method for the synthesis of α-amino phosphoric acids]. Doklady Akademii Nauk SSSR (in Russian). 83: 689ff.
  4. ↑ Fields, Ellis K. (1952). "The synthesis of esters of substituted amino phosphonic acids". Journal of the American Chemical Society. 74 (6): 1528–1531. doi:10.1021/ja01126a054.
  5. ↑ Ali, Tarik E.; Abdel-Kariem, Somaia M. (2015). "Methods for the synthesis of α-heterocyclic/heteroaryl-α-aminophosphonic acids and their esters". Arkivoc. 2015 (6): 246–287. doi:10.3998/ark.5550190.p009.112. hdl:2027/spo.5550190.p009.112.
  6. ↑ Wynberg, H.; Smaardijk, A. (1983). "Asymmetric catalysis in carbon-phosphorus bond formation". Tetrahedron Lett. 24 (52): 5899. doi:10.1016/S0040-4039(00)94232-1.
  7. ↑ Abell, J.; Yamamoto, H. (2008). "Catalytic enantioselective Pudovik reaction of aldimines with tethered bis(8-quinolinato) (TBOx) aluminum complex". J. Am. Chem. Soc. 130 (32): 10521–3. doi:10.1021/ja803859p. PMID 18642910.
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