Fritsch–Buttenberg–Wiechell rearrangement
Chemical reaction series
From Wikipedia, the free encyclopedia
The Fritsch–Buttenberg–Wiechell rearrangement, named for Paul Ernst Moritz Fritsch (1859–1913), 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]
| Fritsch–Buttenberg–Wiechell rearrangement | |
|---|---|
| Named after | Paul Ernst Moritz Fritsch Wilhelm Paul Buttenberg Heinrich G. Wiechell |
| Reaction type | Rearrangement reaction |
| Identifiers | |
| RSC ontology ID | RXNO:0000250 |
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 1,2-diaryl-alkyne product. The mechanism of the FBW rearrangement was a subject of on-surface studies where the vinyl radical was visualised with sub-atomic resolution.[6]
