Claisen rearrangement

The Claisen rearrangement (not to be confused with the Claisen condensation) is a powerful carbon–carbon bond-forming chemical reaction discovered by Rainer Ludwig Claisen. The heating of an allyl vinyl ether will initiate a [3,3]-sigmatropic rearrangement to give a γ,δ-unsaturated carbonyl.

Discovered in 1912, the Claisen rearrangement is the first recorded example of a [3,3]-sigmatropic rearrangement.[1][2][3]

Many reviews have been written.[4][5][6][7]

Mechanism

The Claisen rearrangement is an exothermic (about 84 kJ mol−1), concerted pericyclic reaction which according to the Woodward–Hoffmann rules shows a suprafacial reaction pathway. Crossover experiments eliminate the possibility of the rearrangement occurring via an intermolecular reaction mechanism and are consistent with an intramolecular process, now understood as a [3,3]-electrocyclic reaction.[8][9]

There are substantial solvent effects in the Claisen reactions. More polar solvents tend to accelerate the reaction to a greater extent. Hydrogen-bonding solvents gave the highest rate constants. For example, ethanol/water solvent mixtures give rate constants 10-fold higher than sulfolane.[1][2]

Trivalent organoaluminium reagents, such as trimethylaluminium, have been shown to accelerate this reaction.[10][11]

Variations

Aromatic Claisen rearrangement

The aromatic variation of the Claisen rearrangement is the [3,3]-sigmatropic rearrangement of an allyl phenyl ether to an intermediate which quickly tautomerizes to an ortho-substituted phenol.

Meta-substitution affects the regioselectivity of the ortho rearrangement.[12][13] With the meta constituent in the 3rd position, electron withdrawing functional groups, such as bromide, move the side-chain to the 2nd position (71% of products) while electron donating groups, such as methoxy, shift it to the 6th position (69% of products). If ortho-position is substituted then reaction goes to para position with retention in configuration.[14]

Additionally if an aldehyde or carboxylic acid occupies the substituted position the allyl side-chain displaces the group, releasing it quantitatively as carbon monoxide or carbon dioxide respectively.[15][16]

Bellus–Claisen rearrangement

The Bellus–Claisen rearrangement is the reaction of allylic ethers, amines, and thioethers with ketenes to give γ,δ-unsaturated esters, amides, and thioesters.[17][18][19]

Eschenmoser–Claisen rearrangement

The Eschenmoser–Claisen rearrangement proceeds from an allylic alcohol to a γ,δ-unsaturated amide, and was developed by Albert Eschenmoser in 1964.[20][21]

Mechanism:[14]

Ireland–Claisen rearrangement

The Ireland–Claisen rearrangement is the reaction of an allylic acetate with strong base (such as Lithium diisopropylamide) to give a γ,δ-unsaturated carboxylic acid.[22][23][24] The actual rearrangement occurs from the enolate of the ester—this is the structural analog of the simple alkene in the original Claisen rearrangement.

Mechanism:[14]

Johnson–Claisen rearrangement

The Johnson–Claisen rearrangement is the reaction of an allylic alcohol with an orthoester containing a deprotonatable alpha carbon (e.g. triethyl orthoacetate) to give an γ,δ-unsaturated ester.[25]

Mechanism:[14]

Photo-Claisen rearrangement

The photo-Claisen rearrangement is closely related to the photo-Fries rearrangement, proceeding by a similar mechanism. Aryl ethers undergo the photo-Claisen, while the photo-Fries is experiences by aryl esters.[26]

Hetero-Claisens

Aza–Claisen

An iminium can serve as one of the pi-bonded moieties in the rearrangement.[27]

Chromium oxidation

Chromium can oxidize allylic alcohols to alpha-beta unsaturated ketones on the opposite side of the unsaturated bond from the alcohol. This is via a concerted hetero-Claisen reaction, although there are mechanistic differences since the chromium atom has access to d- shell orbitals which allow the reaction under a less constrained set of geometries.[28][29]

Chen–Mapp reaction

The Chen–Mapp reaction also known as the [3,3]-Phosphorimidate Rearrangement or Staudinger–Claisen Reaction installs a phosphite in the place of an alcohol and takes advantage of the Staudinger reduction to convert this to an imine. The subsequent Claisen is driven by the fact that a P=O double bond is more energetically favorable than a P=N double bond.[30]

Overman rearrangement

Main article: Overman rearrangement

The Overman rearrangement (named after Larry Overman) is a Claisen rearrangement of allylic trichloroacetimidates to allylic trichloroacetamides.[31][32][33]

Overman rearrangement is applicable to synthesis of vicinol diamino comp from 1,2 vicinal allylic diol.

Zwitterionic Claisen rearrangement

Unlike typical Claisen rearrangements which require heating, zwitterionic Claisen rearrangements take place at or below room temperature. The acyl ammonium ions are highly selective for Z-enolates under mild conditions.[34][35]

Claisen rearrangement in nature

The enzyme Chorismate mutase (EC 5.4.99.5) catalyzes the Claisen rearrangement of chorismate ion to prephenate ion, a key intermediate in the shikimic acid pathway (the biosynthetic pathway towards the synthesis of phenylalanine and tyrosine).[36]

References

  1. ↑ 1.0 1.1 Claisen, L. (1912). "Über Umlagerung von Phenol-allyläthern inC-Allyl-phenole". Chemische Berichte 45 (3): 3157. doi:10.1002/cber.19120450348.
  2. ↑ 2.0 2.1 Claisen, L.; Tietze, E. (1925). "Über den Mechanismus der Umlagerung der Phenol-allyläther". Chemische Berichte 58 (2): 275. doi:10.1002/cber.19250580207.
  3. ↑ Claisen, L.; Tietze, E. (1926). "Über den Mechanismus der Umlagerung der Phenol-allyläther. (2. Mitteilung)". Chemische Berichte 59 (9): 2344. doi:10.1002/cber.19260590927.
  4. ↑ Hiersemann, M.; Nubbemeyer, U. (2007) The Claisen Rearrangement. Wiley-VCH. ISBN 3-527-30825-3
  5. ↑ Rhoads, S. J.; Raulins, N. R. (1975). "The Claisen and Cope Rearrangements". Org. React. 22: 1–252. doi:10.1002/0471264180.or022.01. ISBN 0471264180.
  6. ↑ Ziegler, F. E. (1988). "The thermal, aliphatic Claisen rearrangement". Chem. Rev. 88 (8): 1423–1452. doi:10.1021/cr00090a001.
  7. ↑ Wipf, P. (1991). "Claisen Rearrangements". Comp. Org. Syn. 5: 827–873. doi:10.1016/B978-0-08-052349-1.00140-2. ISBN 978-0-08-052349-1.
  8. ↑ Hurd, C. D.; Schmerling, L. (1937). "Observations on the Rearrangement of Allyl Aryl Ethers". J. Am. Chem. Soc. 59: 107. doi:10.1021/ja01280a024.
  9. ↑ Francis A. Carey; Richard J. Sundberg (2007). Advanced Organic Chemistry: Part A: Structure and Mechanisms. Springer. pp. 934–935. ISBN 978-0-387-44897-8.
  10. ↑ Goering, H. L.; Jacobson, R. R. (1958). "A Kinetic Study of the ortho-Claisen Rearrangement1". J. Am. Chem. Soc. 80 (13): 3277. doi:10.1021/ja01546a024.
  11. ↑ White, W. N.; Wolfarth, E. F. (1970). "The o-Claisen rearrangement. VIII. Solvent effects". J. Org. Chem. 35 (7): 2196. doi:10.1021/jo00832a019.
  12. ↑ White, William; and Slater, Carl, William N.; Slater, Carl D. (1961). "The ortho-Claisen Rearrangement. V. The Products of Rearrangement of Allyl m-X-Phenyl Ethers". The Journal of Organic Chemistry 26 (10): 3631–3638. doi:10.1021/jo01068a004.
  13. ↑ Gozzo, Fábio; Fernandes, Sergio; Rodrigues, Denise; Eberlin, Marcos; and Marsaioli, Anita, Fábio Cesar; Fernandes, Sergio Antonio; Rodrigues, Denise Cristina; Eberlin, Marcos Nogueira; Marsaioli, Anita Jocelyne (2003). "Regioselectivity in Aromatic Claisen Rearrangements". The Journal of Organic Chemistry 68 (14): 5493–5499. doi:10.1021/jo026385g. PMID 12839439.
  14. ↑ 14.0 14.1 14.2 14.3 László Kürti; Barbara Czakó (2005). Strategic Applications Of Named Reactions In Organic Synthesis: Background And Detailed Mechanics: 250 Named Reactions. Academic Press. ISBN 978-0-12-429785-2. Retrieved 27 March 2013.
  15. ↑ Adams, Rodger (1944). Organic Reactions, Volume II. Newyork: John Wiley & Sons, Inc. pp. 11–12.
  16. ↑ Claisen, L.; Eisleb, O. (1913). "Über die Umlagerung von Phenolallyläthern in die isomeren Allylphenole". Justus Liebigs Annalen der Chemie 401 (1): p. 90. doi:10.1002/jlac.19134010103.
  17. ↑ Malherbe, R.; Bellus, D. (1978). "A New Type of Claisen Rearrangement Involving 1,3-Dipolar Intermediates. Preliminary communication". Helv. Chim. Acta 61 (8): 3096–3099. doi:10.1002/hlca.19780610836.
  18. ↑ Malherbe, R.; Rist, G.; Bellus, D. (1983). "Reactions of haloketenes with allyl ethers and thioethers: A new type of Claisen rearrangement". J. Org. Chem. 48 (6): 860–869. doi:10.1021/jo00154a023.
  19. ↑ Gonda, J. (2004). "The Belluš–Claisen Rearrangement". Angew. Chem. Int. Ed. 43 (27): 3516–3524. doi:10.1002/anie.200301718.
  20. ↑ Wick, A. E.; Felix, D.; Steen, K.; Eschenmoser, A. (1964). "CLAISEN'sche Umlagerungen bei Allyl- und Benzylalkoholen mit Hilfe von Acetalen des N, N-Dimethylacetamids. Vorläufige Mitteilung". Helv. Chim. Acta 47 (8): 2425–2429. doi:10.1002/hlca.19640470835.
  21. ↑ Wick, A. E.; Felix, D.; Gschwend-Steen, K.; Eschenmoser, A. (1969). "CLAISEN'sche Umlagerungen bei Allyl- und Benzylalkoholen mit 1-Dimethylamino-1-methoxy-äthen". Helv. Chim. Acta 52 (4): 1030–1042. doi:10.1002/hlca.19690520418.
  22. ↑ Ireland, R. E.; Mueller, R. H. (1972). "Claisen rearrangement of allyl esters". Journal of the American Chemical Society 94 (16): 5897. doi:10.1021/ja00771a062.
  23. ↑ Ireland, R. E.; Willard, A. K. (1975). "The stereoselective generation of ester enolates". Tetrahedron Lett. 16 (46): 3975–3978. doi:10.1016/S0040-4039(00)91213-9.
  24. ↑ Ireland, R. E.; Mueller, R. H.; Willard, A. K. (1976). "The ester enolate Claisen rearrangement. Stereochemical control through stereoselective enolate formation". Journal of the American Chemical Society 98 (10): 2868. doi:10.1021/ja00426a033.
  25. ↑ Johnson, W. S. et al. (1970). "Simple stereoselective version of the Claisen rearrangement leading to trans-trisubstituted olefinic bonds. Synthesis of squalene". J. Am. Chem. Soc. 92 (3): 741. doi:10.1021/ja00706a074. |first3= missing |last3= in Authors list (help); |first4= missing |last4= in Authors list (help); |first5= missing |last5= in Authors list (help); |first6= missing |last6= in Authors list (help); |first7= missing |last7= in Authors list (help)
  26. ↑ IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006–) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. doi:10.1351/goldbook
  27. ↑ Kurth, M. J.; Decker, O. H. W. (1985). "Enantioselective preparation of 3-substituted 4-pentenoic acids via the Claisen rearrangement". J. Org. Chem. 50 (26): 5769–5775. doi:10.1021/jo00350a067.
  28. ↑ Dauben, W. G.; Michno, D. M. (1977). "Direct oxidation of tertiary allylic alcohols. A simple and effective method for alkylative carbonyl transposition". J. Org. Chem. 42 (4): 682. doi:10.1021/jo00424a023.
  29. ↑ "(R)-(+)-3,4-Dimethylcyclohex-2-en-1-one ((R)-(+)-3,4-Dimethyl-2-cyclohexen-1-one)". Org. Synth. 82: 108. 2005.
  30. ↑ Chen, B.; Mapp, A. (2005). "Thermal and catalyzed 3,3-phosphorimidate rearrangements". Journal of the American Chemical Society 127 (18): 6712–6718. doi:10.1021/ja050759g. PMID 15869293.
  31. ↑ Overman, L. E. (1974). "Thermal and mercuric ion catalyzed [3,3]-sigmatropic rearrangement of allylic trichloroacetimidates. 1,3 Transposition of alcohol and amine functions". Journal of the American Chemical Society 96 (2): 597–599. doi:10.1021/ja00809a054.
  32. ↑ Overman, L. E. (1976). "A general method for the synthesis of amines by the rearrangement of allylic trichloroacetimidates. 1,3 Transposition of alcohol and amine functions". Journal of the American Chemical Society 98 (10): 2901–2910. doi:10.1021/ja00426a038.
  33. ↑ Organic Syntheses, Coll. Vol. 6, p.507; Vol. 58, p.4 (Article)
  34. ↑ Yu, C.-M.; Choi, H.-S.; Lee, J.; Jung, W.-H.; Kim, H.-J. (1996). "Self-regulated molecular rearrangement: Diastereoselective zwitterionic aza-Claisen protocol". J. Chem. Soc., Perkin Trans. 1 (2): 115–116. doi:10.1039/p19960000115.
  35. ↑ Nubbemeyer, U. (1995). "1,2-Asymmetric Induction in the Zwitterionic Claisen Rearrangement of Allylamines". J. Org. Chem. 60 (12): 3773–3780. doi:10.1021/jo00117a032.
  36. ↑ Ganem, B. (1996). "The Mechanism of the Claisen Rearrangement: Déjà Vu All over Again". Angew. Chem. Int. Ed. Engl. 35 (9): 936–945. doi:10.1002/anie.199609361.

See also