Formation of [5.5]cyclopentadienidophanes by macrocyclization of [3-(methylammonio)propyl]cyclopentadienides under Mannich conditions
In: Tetrahedron, Jg. 65 (2009-07-18), Heft 29/30, S. 5733-5738
academicJournal
Zugriff:
Abstract: 2-Acyl-1,4-bis(methoxycarbonyl)-3-[3-(methylammonio)propyl]cyclopentadienides 1 and aqueous formaldehyde can undergo a double Mannich reaction leading to the bisbetainic 2,12-diazonia-[5,5](1,3)cyclopentadienidophanes 2. The success of this macrocyclization reaction seems to depend on the length of the ω-ammonioalkyl chain and the individual acyl substituent. In the cases of ω-(methylammonio)butyl and ω-(methylammonio)pentyl chains, as well as with ω-ammoniopropyl derivatives bearing particularly electron-rich 4-methoxybenzoyl or 2-furoyl substituents, a mixture of oligomers is formed. On the other hand, DCC-assisted cyclocondensation of 1b,d (acyl=4-methoxybenzoyl and thiophene-2-carbonyl, respectively) occurs only intramolecularly, leading to the bicyclic 6-aminopentafulvenes 4b,d in good yields. [Copyright &y& Elsevier]
Titel: |
Formation of [5.5]cyclopentadienidophanes by macrocyclization of [3-(methylammonio)propyl]cyclopentadienides under Mannich conditions
|
---|---|
Autor/in / Beteiligte Person: | Maas, Gerhard ; Müller, Andreas ; Endres, Andreas ; Schatz, Jürgen |
Link: | |
Zeitschrift: | Tetrahedron, Jg. 65 (2009-07-18), Heft 29/30, S. 5733-5738 |
Veröffentlichung: | 2009 |
Medientyp: | academicJournal |
ISSN: | 0040-4020 (print) |
DOI: | 10.1016/j.tet.2009.05.014 |
Schlagwort: |
|
Sonstiges: |
|