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Abstract The thermal rearrangements of 1,2-dialkynylimidazoles have been shown to lead to trapping products of cyclopenta[b]pyrazine carbene intermediates. Here we show that a similar rearrangement also occurs in the case of 1,2-diethynyl-1H-pyrrole, and that trapping the intermediate cyclopenta[b]pyridine carbene with solvent THF affords an ylide that undergoes a Stevens rearrangement to a spirocyclic product. An analogous rearrangement and trapping is observed for thermolysis of 1,2-dialkynylimidazoles in THF or 1,4-dioxane.
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This content will become publicly available on December 5, 2025
Generation and interception of bicyclo[3.2.1]oct-2-yne: an experimental and theoretical mechanistic study
Bicyclo[3.2.1]oct-2-yne was generated from the Fritsch–Buttenberg–Wiechell rearrangement of 2-norbornylidene carbene. The rearrangement preferentially involves migration of a tertiary carbon over a secondary carbon, a trend that contrasts with rearrangements of acyclic carbenes and which may be attributable to hyperconjugative effects promoted by the bridged structure of the carbene.
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- Award ID(s):
- 2102579
- PAR ID:
- 10587115
- Publisher / Repository:
- RSC
- Date Published:
- Journal Name:
- Chemical Communications
- Volume:
- 60
- Issue:
- 98
- ISSN:
- 1359-7345
- Page Range / eLocation ID:
- 14573 to 14576
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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