Hyperconjugative Antiaromaticity Activates 4 H -Pyrazoles as Inverse-Electron-Demand Diels–Alder Dienes
The Diels-Alder reactivity of 4,4-difluoro-3,5-diphenyl-4H-pyrazole was investigated experimentally and computationally with endo-bicyclo[6.1.0]non-4-yne. The computationally predicted rate enhancement from hyperconjugative antiaromaticity induced by fluorination of cyclopentadienes at the 5-positio...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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American Chemical Society (ACS)
2020
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| Online Access: | https://hdl.handle.net/1721.1/128547 |
| _version_ | 1811077345550794752 |
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| author | Levandowski, Brian Abularrage, Nile S Houk, KN Raines, Ronald T |
| author2 | Massachusetts Institute of Technology. Department of Chemistry |
| author_facet | Massachusetts Institute of Technology. Department of Chemistry Levandowski, Brian Abularrage, Nile S Houk, KN Raines, Ronald T |
| author_sort | Levandowski, Brian |
| collection | MIT |
| description | The Diels-Alder reactivity of 4,4-difluoro-3,5-diphenyl-4H-pyrazole was investigated experimentally and computationally with endo-bicyclo[6.1.0]non-4-yne. The computationally predicted rate enhancement from hyperconjugative antiaromaticity induced by fluorination of cyclopentadienes at the 5-position extends to five-membered heterocyclic dienes containing a saturated center. 4,4-Difluoro-4H-pyrazoles are new electron-deficient dienes with rapid reactivities toward strained alkynes. |
| first_indexed | 2024-09-23T10:41:29Z |
| format | Article |
| id | mit-1721.1/128547 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T10:41:29Z |
| publishDate | 2020 |
| publisher | American Chemical Society (ACS) |
| record_format | dspace |
| spelling | mit-1721.1/1285472022-09-30T22:19:04Z Hyperconjugative Antiaromaticity Activates 4 H -Pyrazoles as Inverse-Electron-Demand Diels–Alder Dienes Levandowski, Brian Abularrage, Nile S Houk, KN Raines, Ronald T Massachusetts Institute of Technology. Department of Chemistry The Diels-Alder reactivity of 4,4-difluoro-3,5-diphenyl-4H-pyrazole was investigated experimentally and computationally with endo-bicyclo[6.1.0]non-4-yne. The computationally predicted rate enhancement from hyperconjugative antiaromaticity induced by fluorination of cyclopentadienes at the 5-position extends to five-membered heterocyclic dienes containing a saturated center. 4,4-Difluoro-4H-pyrazoles are new electron-deficient dienes with rapid reactivities toward strained alkynes. National Institutes of Health (Grant R01-GM044783) National Science Foundation (Grant CHE-1764328) 2020-11-20T18:37:43Z 2020-11-20T18:37:43Z 2019-10 2019-09 2020-11-19T17:45:41Z Article http://purl.org/eprint/type/JournalArticle 1523-7052 1523-7060 https://hdl.handle.net/1721.1/128547 Levandowski, Brian J. "Hyperconjugative Antiaromaticity Activates 4 H -Pyrazoles as Inverse-Electron-Demand Diels–Alder Dienes." Organic Letters 21, 20 (October 2019): 8492–8495 © 2019 American Chemical Society en http://dx.doi.org/10.1021/ACS.ORGLETT.9B03351 Organic Letters Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Chemical Society (ACS) PMC |
| spellingShingle | Levandowski, Brian Abularrage, Nile S Houk, KN Raines, Ronald T Hyperconjugative Antiaromaticity Activates 4 H -Pyrazoles as Inverse-Electron-Demand Diels–Alder Dienes |
| title | Hyperconjugative Antiaromaticity Activates 4 H -Pyrazoles as Inverse-Electron-Demand Diels–Alder Dienes |
| title_full | Hyperconjugative Antiaromaticity Activates 4 H -Pyrazoles as Inverse-Electron-Demand Diels–Alder Dienes |
| title_fullStr | Hyperconjugative Antiaromaticity Activates 4 H -Pyrazoles as Inverse-Electron-Demand Diels–Alder Dienes |
| title_full_unstemmed | Hyperconjugative Antiaromaticity Activates 4 H -Pyrazoles as Inverse-Electron-Demand Diels–Alder Dienes |
| title_short | Hyperconjugative Antiaromaticity Activates 4 H -Pyrazoles as Inverse-Electron-Demand Diels–Alder Dienes |
| title_sort | hyperconjugative antiaromaticity activates 4 h pyrazoles as inverse electron demand diels alder dienes |
| url | https://hdl.handle.net/1721.1/128547 |
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