Mackert, Peter J. ; Hafner, Klaus ; Nimmerfroh, Norbert ; Banert, Klaus (2023)
Synthesis, Structure and Reactivity of Cyclopenta-annulated 1,2,3,4-Tetrazines.
In: Chemische Berichte, 1994, 127 (8)
doi: 10.26083/tuprints-00022380
Artikel, Zweitveröffentlichung, Verlagsversion
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Kurzbeschreibung (Abstract)
The 2-aryl-2H-cyclopenta[e]-1,2,3,4-tetrazines 3a-n are formed by coupling of the diazocyclopentadienes 1a and 1b with arenediazonium salts and subsequent reversible electrocyclization of the primary coupling products 2a-n. From the solutions of the equilibrium mixtures of 2a ⇌ 3a - 2n ⇌ 3n the tetrazines 3a-d, h-k and the arylazo-diazocyclopentadienes 2e-g and 21-n crystallize. The 2-methyl-2H-cyclopenta[e]-1,2,3,4-tetrazines 3o and 3p are obtained by addition of methyllithium to 1a and 1b followed by a diazo transfer reaction and cyclization. In solutions of 3o and 3p the ring-opened isomers 2o and 2p could not be detected. X-ray analyses of 3h and 3p prove their bicyclic planar geometry in the solid state. ¹⁵N-NMR and temperature-dependent ¹H-NMR spectroscopy have enabled a detailed study of the reversible ring closure reaction in the case of 2d ⇌ 3d. Reaction of 2-phenyl-2H-cyclopenta[e]-1,2,3,4-tetrazine (3b) with tetrafluoroboric acid results in the formation of the protonated monocyclic salt 4. Furthermore 3b undergoes electrophilic substitution reactions preferably at C-7, as demonstrated by bromination, formylation, and trifluoroacetylation. Photolysis of solutions of 2i/3i, 2k/3k, and 21/31 leads to the ketene imines 11a-c. The structure of 11c has been determined by X-ray crystallography.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2023 |
| Autor(en): | Mackert, Peter J. ; Hafner, Klaus ; Nimmerfroh, Norbert ; Banert, Klaus |
| Art des Eintrags: | Zweitveröffentlichung |
| Titel: | Synthesis, Structure and Reactivity of Cyclopenta-annulated 1,2,3,4-Tetrazines |
| Sprache: | Englisch |
| Publikationsjahr: | 2023 |
| Ort: | Darmstadt |
| Publikationsdatum der Erstveröffentlichung: | 1994 |
| Verlag: | Wiley |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Chemische Berichte |
| Jahrgang/Volume einer Zeitschrift: | 127 |
| (Heft-)Nummer: | 8 |
| DOI: | 10.26083/tuprints-00022380 |
| URL / URN: | https://tuprints.ulb.tu-darmstadt.de/22380 |
| Zugehörige Links: | |
| Herkunft: | Zweitveröffentlichungsservice |
| Kurzbeschreibung (Abstract): | The 2-aryl-2H-cyclopenta[e]-1,2,3,4-tetrazines 3a-n are formed by coupling of the diazocyclopentadienes 1a and 1b with arenediazonium salts and subsequent reversible electrocyclization of the primary coupling products 2a-n. From the solutions of the equilibrium mixtures of 2a ⇌ 3a - 2n ⇌ 3n the tetrazines 3a-d, h-k and the arylazo-diazocyclopentadienes 2e-g and 21-n crystallize. The 2-methyl-2H-cyclopenta[e]-1,2,3,4-tetrazines 3o and 3p are obtained by addition of methyllithium to 1a and 1b followed by a diazo transfer reaction and cyclization. In solutions of 3o and 3p the ring-opened isomers 2o and 2p could not be detected. X-ray analyses of 3h and 3p prove their bicyclic planar geometry in the solid state. ¹⁵N-NMR and temperature-dependent ¹H-NMR spectroscopy have enabled a detailed study of the reversible ring closure reaction in the case of 2d ⇌ 3d. Reaction of 2-phenyl-2H-cyclopenta[e]-1,2,3,4-tetrazine (3b) with tetrafluoroboric acid results in the formation of the protonated monocyclic salt 4. Furthermore 3b undergoes electrophilic substitution reactions preferably at C-7, as demonstrated by bromination, formylation, and trifluoroacetylation. Photolysis of solutions of 2i/3i, 2k/3k, and 21/31 leads to the ketene imines 11a-c. The structure of 11c has been determined by X-ray crystallography. |
| Status: | Verlagsversion |
| URN: | urn:nbn:de:tuda-tuprints-223801 |
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 500 Naturwissenschaften und Mathematik > 540 Chemie |
| Fachbereich(e)/-gebiet(e): | 07 Fachbereich Chemie 07 Fachbereich Chemie > Clemens-Schöpf-Institut 07 Fachbereich Chemie > Clemens-Schöpf-Institut > Fachgebiet Organische Chemie |
| Hinterlegungsdatum: | 20 Mär 2023 11:29 |
| Letzte Änderung: | 02 Aug 2024 12:51 |
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| Suche nach Titel in: | TUfind oder in Google |
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- Synthesis, Structure and Reactivity of Cyclopenta-annulated 1,2,3,4-Tetrazines. (deposited 20 Mär 2023 11:29) [Gegenwärtig angezeigt]
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