Synthesis of the [11]Cyclacene Framework by Repetitive Diels–Alder Cycloadditions
The Diels–Alder cycloaddition between bisdienes and bisdienophile incorporating the 7-oxa-bicyclo[2.2.1]heptane unit are well known to show high diastereoselectivity that can be exploited for the synthesis of molecular belts. The related bisdiene 5,6,7,8-tetramethylidene-2-bicyclo[2.2.2]octene is a...
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MDPI AG
2021-05-01
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| author | John B. Bauer Fatima Diab Cäcilia Maichle-Mössmer Hartmut Schubert Holger F. Bettinger |
| author_facet | John B. Bauer Fatima Diab Cäcilia Maichle-Mössmer Hartmut Schubert Holger F. Bettinger |
| author_sort | John B. Bauer |
| collection | DOAJ |
| description | The Diels–Alder cycloaddition between bisdienes and bisdienophile incorporating the 7-oxa-bicyclo[2.2.1]heptane unit are well known to show high diastereoselectivity that can be exploited for the synthesis of molecular belts. The related bisdiene 5,6,7,8-tetramethylidene-2-bicyclo[2.2.2]octene is a valuable building block for the synthesis of photoprecursors for acenes, but it has not been employed for the synthesis of molecular belts. The present work investigates by computational means the Diels–Alder reaction between these bisdiene building blocks with <i>syn</i>-1,4,5,8-tetrahydro-1,4:5,8-diepoxyanthracene, which shows that the diastereoselectivity of the Diels–Alder reaction of the etheno-bridged bisdiene is lower than that of the epoxy-bridged bisdiene. The reaction of the etheno-bridged bisdiene and <i>syn</i>-1,4,5,8-tetrahydro-1,4:5,8-diepoxyanthracene in 2:1 ratio yields two diastereomers that differ in the orientation of the oxa and etheno bridges based on NMR and X-ray crystallography. The all-<i>syn</i> diastereomer can be transformed into a molecular belt by inter- and intramolecular Diels–Alder reactions with a bifunctional building block. The molecular belt could function as a synthetic intermediate <i>en route</i> to a [11]cyclacene photoprecursor. |
| first_indexed | 2024-03-10T11:14:02Z |
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| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-10T11:14:02Z |
| publishDate | 2021-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-3fba36f6f8e44cf9ba49bdcfe842ba8f2023-11-21T20:32:36ZengMDPI AGMolecules1420-30492021-05-012610304710.3390/molecules26103047Synthesis of the [11]Cyclacene Framework by Repetitive Diels–Alder CycloadditionsJohn B. Bauer0Fatima Diab1Cäcilia Maichle-Mössmer2Hartmut Schubert3Holger F. Bettinger4Institut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, GermanyInstitut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, GermanyInstitut für Anorganische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, GermanyInstitut für Anorganische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, GermanyInstitut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, GermanyThe Diels–Alder cycloaddition between bisdienes and bisdienophile incorporating the 7-oxa-bicyclo[2.2.1]heptane unit are well known to show high diastereoselectivity that can be exploited for the synthesis of molecular belts. The related bisdiene 5,6,7,8-tetramethylidene-2-bicyclo[2.2.2]octene is a valuable building block for the synthesis of photoprecursors for acenes, but it has not been employed for the synthesis of molecular belts. The present work investigates by computational means the Diels–Alder reaction between these bisdiene building blocks with <i>syn</i>-1,4,5,8-tetrahydro-1,4:5,8-diepoxyanthracene, which shows that the diastereoselectivity of the Diels–Alder reaction of the etheno-bridged bisdiene is lower than that of the epoxy-bridged bisdiene. The reaction of the etheno-bridged bisdiene and <i>syn</i>-1,4,5,8-tetrahydro-1,4:5,8-diepoxyanthracene in 2:1 ratio yields two diastereomers that differ in the orientation of the oxa and etheno bridges based on NMR and X-ray crystallography. The all-<i>syn</i> diastereomer can be transformed into a molecular belt by inter- and intramolecular Diels–Alder reactions with a bifunctional building block. The molecular belt could function as a synthetic intermediate <i>en route</i> to a [11]cyclacene photoprecursor.https://www.mdpi.com/1420-3049/26/10/3047Diels–Alder reactioncyclacenediastereoselectivityzigzag hydrocarbon beltdensity functional theorycycloaddition |
| spellingShingle | John B. Bauer Fatima Diab Cäcilia Maichle-Mössmer Hartmut Schubert Holger F. Bettinger Synthesis of the [11]Cyclacene Framework by Repetitive Diels–Alder Cycloadditions Molecules Diels–Alder reaction cyclacene diastereoselectivity zigzag hydrocarbon belt density functional theory cycloaddition |
| title | Synthesis of the [11]Cyclacene Framework by Repetitive Diels–Alder Cycloadditions |
| title_full | Synthesis of the [11]Cyclacene Framework by Repetitive Diels–Alder Cycloadditions |
| title_fullStr | Synthesis of the [11]Cyclacene Framework by Repetitive Diels–Alder Cycloadditions |
| title_full_unstemmed | Synthesis of the [11]Cyclacene Framework by Repetitive Diels–Alder Cycloadditions |
| title_short | Synthesis of the [11]Cyclacene Framework by Repetitive Diels–Alder Cycloadditions |
| title_sort | synthesis of the 11 cyclacene framework by repetitive diels alder cycloadditions |
| topic | Diels–Alder reaction cyclacene diastereoselectivity zigzag hydrocarbon belt density functional theory cycloaddition |
| url | https://www.mdpi.com/1420-3049/26/10/3047 |
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