To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

4,5
Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.
.
Leo
Newton
Brights
Milds

Gomberg–Bachmann reaction

From Wikipedia, the free encyclopedia

Gomberg–Bachmann reaction
Named after Moses Gomberg
Werner Emmanuel Bachmann
Reaction type Coupling reaction

The Gomberg–Bachmann reaction, named for the Russian-American chemist Moses Gomberg and the American chemist Werner Emmanuel Bachmann, is an aryl-aryl coupling reaction via a diazonium salt.[1][2][3]

Gomberg-Bachmann reaction

The arene compound (here benzene) is reacted with a diazonium salt in the presence of a base to provide the biaryl through an intermediate aryl radical. For example, p-bromobiphenyl may be prepared from 4-bromoaniline and benzene:[4]

BrC6H4NH2 + C6H6 → BrC6H4−C6H5

The reaction offers a wide scope for both diazonium component and arene component but yields are generally low following the original procedure (less than 40%), given the many side-reactions of diazonium salts. Several improvements have been suggested. One possibility is to employ diazonium tetrafluoroborates in arene solvent together with a phase-transfer catalyst,[5] another is to use 1-aryl-3,3-dialkyltriazenes.[6]

Pschorr reaction

One intramolecular variation which gives better results is the Pschorr cyclization:[7][8][9]

Pschorr reaction

The group Z can be CH2, CH2CH2, NH and CO (to fluorenone[10]) to name just a few.

See also

References

  1. ^ Gomberg, M.; Bachmann, W. E. (1924). "The Synthesis of Biaryl Compounds by Means of the Diazo Reaction". J. Am. Chem. Soc. 42 (10): 2339–2343. doi:10.1021/ja01675a026.
  2. ^ W. Pötsch. Lexikon bedeutender Chemiker (VEB Bibliographisches Institut Leipzig, 1989) (ISBN 3817110553)
  3. ^ Smith, Michael B.; March, Jerry (2007), Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (6th ed.), New York: Wiley-Interscience, ISBN 978-0-471-72091-1
  4. ^ M. Gomberg; W. E. Bachmann (1928). "p-Bromobiphenyl". Organic Syntheses. 8: 42. doi:10.15227/orgsyn.008.0042.; Collective Volume, vol. 1, p. 113
  5. ^ J. R. Beadle, S. H. Korzeniowski, D .E. Rosenberg, B. J. Garcia-Slanga, G. W. Gokel; Korzeniowski; Rosenberg; Garcia-Slanga; Gokel (1984). "Phase-transfer-catalyzed Gomberg-Bachmann synthesis of unsymmetrical biarenes: a survey of catalysts and substrates". J. Org. Chem. 49 (9): 1594–603. doi:10.1021/jo00183a021.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  6. ^ T. B. Patrick, R. P. Willaredt, D. J. DeGonia (1985). "Synthesis of biaryls from aryltriazenes". J. Org. Chem. 50 (13): 2232–2235. doi:10.1021/jo00213a007.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  7. ^ Pschorr, Robert (1896). "Neue Synthese des Phenanthrens und seiner Derivate" [New Synthesis of Phenanthrene and Its Derivatives]. Chem. Ber. (in German). 29 (1): 496–501. doi:10.1002/cber.18960290198.
  8. ^ March, Jerry (1985), Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 3rd edition, New York: Wiley, ISBN 9780471854722, OCLC 642506595
  9. ^ Laali, Kenneth K.; Shokouhimehr, Mohammadreza (2009). "The Pschorr Reaction, a Fresh Look at a Classical Transformation". Current Organic Synthesis. 6 (2): 193–202. doi:10.2174/157017909788167275.
  10. ^ Stephen A. Chandler; Peter Hanson; Alec B. Taylor; Paul H. Walton; Allan W. Timms (2001). "Sandmeyer reactions. Part 5.1 Estimation of the rates of 1,5-aryl/aryl radical translocation and cyclisation during Pschorr fluorenone synthesis with a comparative analysis of reaction energetics". J. Chem. Soc., Perkin Trans. 2 (2): 214–228. doi:10.1039/b006184k.
This page was last edited on 26 February 2022, at 11:13
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.