Chemistry:Wurtz–Fittig reaction

From HandWiki
Short description: Chemical reaction
Wurtz–Fittig reaction
Named after Charles Adolphe Wurtz
Wilhelm Rudolph Fittig
Reaction type Coupling reaction
Identifiers
Organic Chemistry Portal wurtz-fittig-reaction

The Wurtz–Fittig reaction is the chemical reaction of an aryl halide, alkyl halides, and sodium metal to give substituted aromatic compounds.[1] Following the work of Charles Adolphe Wurtz on the sodium-induced coupling of alkyl halides (the Wurtz reaction), Wilhelm Rudolph Fittig extended the approach to the coupling of an alkyl halide with an aryl halide.Cite error: Closing </ref> missing for <ref> tag Typically the reaction is used for the alkylation of aryl halides. With the use of ultrasound sodium reacts with some aryl halides to produce biphenyl compounds.[2]

Mechanism

The mechanism of the Wurtz–Fittig reaction has not been the subject of modern investigations. The process was once proposed to involve the combination of an alkyl and aryl radicals.[3][4] Another mechanistic proposal invoked the generation of organosodium intermediates.[5] The reaction of sodium and chlorobenzene produces triphenylene, which supports a role for radicals.[5] A role for organosodium compounds is supported by indirect evidence.[4][3] For example, addition of carbon dioxide to a mixture of sodium and isobutyl bromide results in the formation of 3-methylbutanoic acid after acid workup. [6][7]

Use of other metals

The Wurtz–Fittig reaction can be conducted using metals other than sodium. Some examples include potassium, iron, copper, and lithium.[8] When lithium is used, the reaction occurs with appreciable yield only under ultrasound.[9] Ultrasound is known to cleave halogen atoms from aryl and alkyl halides through a free-radical mechanism[10]

Applications

The Wurtz–Fittig reaction has limited applicability, because it is plagued by side reactions including rearrangements and eliminations.[8] The reaction has been applied to the laboratory synthesis of some organosilicon compounds.[11] One example is the conversion of tetraethyl orthosilicate to the mono-tert-butoxy derivative in 40% yield as summarized in this idealized equation:[12]

Si(OC
2H
5)
4 + 2 Na + (CH
3)
3CCl → Si(OC
2H
5)
3OC(CH
3)
3 + NaCl + C
2H
5ONa

Molten sodium was used.

Other organosilicon compounds synthesized using the Wurtz–Fittig reaction include silylated calixarenes[13] and vinylsilanes.[14]

See also

References

  1. ↑ Wang, Zerong (2010). "Wurtz–Fittig Reaction". Comprehensive Organic Name Reactions and Reagents. 686. pp. 3100–3104. doi:10.1002/9780470638859.conrr686. ISBN 9780470638859. 
  2. ↑ Laue, Thomas; Plagens, Andreas (2005). Named Organic Reactions (2nd ed.). Wolfsburg, Germany: John Wiley & Sons. p. 305. ISBN 9780470010402. https://archive.org/details/namedorganicreac00laue_814. 
  3. ↑ 3.0 3.1 Wooster, Charles Bushnell (1932). "Organo-alkali Compounds". Chemical Reviews 11 (1): 1–91. doi:10.1021/cr60038a001. ISSN 0009-2665. 
  4. ↑ 4.0 4.1 Gilman, Henry; Wright, George F. (1933). "The Mechanism of the Wurtz—Fittig Reaction. The Direct Preparation of an Organosodium (Potassium) Compound from an RX Compound". Journal of the American Chemical Society 55 (7): 2893–2896. doi:10.1021/ja01334a044. ISSN 0002-7863. 
  5. ↑ 5.0 5.1 Bachmann, W. E.; Clarke, H. T. (1927). "The Mechanism of the Wurtz–Fittig Reaction". Journal of the American Chemical Society 49 (8): 2089–2098. doi:10.1021/ja01407a038. ISSN 0002-7863. 
  6. ↑ Schorigin, Paul (1908). "Synthesen mittels Natrium und Halogenalkylen". Berichte der Deutschen Chemischen Gesellschaft 41 (2): 2711–2717. doi:10.1002/cber.190804102208. https://zenodo.org/record/1426291. 
  7. ↑ Schorigin, Paul (1910). "Über die Natriumalkyle und über ihre Reaktion mit den Äthern". Berichte der Deutschen Chemischen Gesellschaft 43 (2): 1931–1938. doi:10.1002/cber.191004302128. https://zenodo.org/record/1794645. 
  8. ↑ 8.0 8.1 Smith, Michael; March, Jerry (2007). March's advanced organic chemistry: Reactions, mechanisms, and structure. (6th ed.). Hoboken, N.J.: Wiley-Interscience. ISBN 978-0471720911. OCLC 69020965. 
  9. ↑ Han, Byung Hee; Boudjouk, Philip (1981). "Organic sonochemistry. Ultrasound-promoted coupling of organic halides in the presence of lithium wire". Tetrahedron Letters 22 (29): 2757–2758. doi:10.1016/S0040-4039(01)90544-1. ISSN 0040-4039. 
  10. ↑ Prakash, S.; Pandey, J. D. (1965). "Sonocleavage of halogens from aliphatic chains and aromatic rings". Tetrahedron 21 (4): 903–908. doi:10.1016/0040-4020(65)80026-6. ISSN 0040-4020. 
  11. ↑ Bassett, E. A.; Emblem, H. G.; Frankel, M.; Ridge, D. (1948). "The use of the Wurtz–Fittig reaction in the preparation of organo-substituted silanes". Journal of the Society of Chemical Industry 67 (5): 177–179. doi:10.1002/jctb.5000670503. ISSN 0368-4075. 
  12. ↑ Chappelow, C. C.; Elliott, R. L.; Goodwin, J. T. (1962). "Synthesis of t-Butylsilicon Compounds by the Wurtz–Fitting Reaction". The Journal of Organic Chemistry 27 (4): 1409–1414. doi:10.1021/jo01051a069. ISSN 0022-3263. 
  13. ↑ Hudrlik, Paul F.; Arasho, Wondwossen D.; Hudrlik, Anne M. (2007). "The Wurtz–Fittig Reaction in the Preparation of C-Silylated Calixarenes". The Journal of Organic Chemistry 72 (21): 8107–8110. doi:10.1021/jo070660n. ISSN 0022-3263. PMID 17850095. 
  14. ↑ Adam, Waldemar; Richter, Markus J. (1994). "One-Pot Synthesis of α-Trimethylsilyl Enones from Vinylsilanes". Synthesis 1994 (2): 176–180. doi:10.1055/s-1994-25433. ISSN 0039-7881. 



Retrieved from "https://handwiki.org/wiki/index.php?title=Chemistry:Wurtz–Fittig_reaction&oldid=3331599"