Fritsch–Buttenberg–Wiechell rearrangement
The Fritsch–Buttenberg–Wiechell rearrangement, named for Paul Ernst Moritz Fritsch, Wilhelm Paul Buttenberg, and Heinrich G. Wiechell, is a chemical reaction whereby a 1,1-diaryl-2-bromo-alkene rearranges to a 1,2-diaryl-alkyne by reaction with a strong base such as an alkoxide.[1][2][3] [4]
This rearrangement is also possible with alkyl substituents.[5]
Reaction Mechanism
The strong base deprotonates the vinylic hydrogen, which after alpha-elimination forms a vinyl carbene. A 1,2-aryl migration forms the desired product, the 1,2-diaryl-alkyne.
Scope
One study explored this reaction for the synthesis of novel polyynes:[6][7]
References
- ^ Paul Fritsch (1894). "Ueber die Darstellung von Diphenylacetaldehyd und eine neue Synthese von Tolanderivaten". Justus Liebig's Annalen der Chemie. 279 (3): 319–323. doi:10.1002/jlac.18942790310.
- ^ Buttenberg, W. P. (1894). "Condensation des Dichloracetals mit Phenol und Toluol". Justus Liebig's Annalen der Chemie. 279 (3): 324–337. doi:10.1002/jlac.18942790311.
- ^ Wiechell, H. (1894). "Condensation des Dichloracetals mit Anisol und Phenetol". Justus Liebig's Annalen der Chemie. 279 (3): 337–344. doi:10.1002/jlac.18942790312.
- ^ Köbrich, G. (1965). "Eliminations from Olefins". Angewandte Chemie International Edition. 4: 49–68. doi:10.1002/anie.196500491.
- ^ Rezaei, H.; Yamanoi, S.; Chemla, F.; Normant, J. F. (2000). "Fritsch-Buttenberg-Wiechell Rearrangement in the Aliphatic Series". Org. Lett. 2 (4): 419–421. doi:10.1021/ol991117z.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ One-Pot Formation and Derivatization of Di- and Triynes Based on the Fritsch-Buttenberg-Wiechell Rearrangement Thanh Luu, Yasuhiro Morisaki, Nina Cunningham, and Rik R. Tykwinski J. Org. Chem. 2007, 72, 9622–9629 doi:10.1021/jo701810g
- ^ The metal acetylide intermediate is captured by electrophile methyl iodide. The reaction product is a biomolecule found in for instance Bidens pilosa
1. Darses, B.; Milet, A.; Philouze, C.; Greene, A. E.; Poisson, J.-F. o., Ynol Ethers from Dichloroenol Ethers: Mechanistic Elucidation Through 35Cl Labeling. Organic Letters 2008, 10 (20), 4445-4447.