Triggering and preventing cyclization of o-amino-guanidinobenzenes to 2-amino-benzimidazoles

Aromatic compounds in which a primary or secondary amino group is positioned next (in ortho position) to a guanidino group have been reported as intermediates in a variety of reactions, but are generally prone to cyclization to give 2-amino-imidazoles. Here, we present a comprehensive analysis, base...

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Hauptverfasser: Henel, Carmen L. M. (VerfasserIn) , Michel, Edwin (VerfasserIn) , Zeitler, Devin (VerfasserIn) , Hübner, Olaf (VerfasserIn) , Kaifer, Elisabeth (VerfasserIn) , Himmel, Hans-Jörg (VerfasserIn)
Dokumenttyp: Article (Journal)
Sprache:Englisch
Veröffentlicht: 9 January 2026
In: Chemistry - a European journal
Year: 2026, Jahrgang: 32, Heft: 2, Pages: 1-15
ISSN:1521-3765
DOI:10.1002/chem.202503147
Online-Zugang:Verlag, kostenfrei, Volltext: https://doi.org/10.1002/chem.202503147
Verlag, kostenfrei, Volltext: https://onlinelibrary.wiley.com/doi/abs/10.1002/chem.202503147
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Verfasserangaben:Carmen L.M. Henel, Edwin Michel, Devin Zeitler, Olaf Hübner, Elisabeth Kaifer, Hans-Jörg Himmel
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Zusammenfassung:Aromatic compounds in which a primary or secondary amino group is positioned next (in ortho position) to a guanidino group have been reported as intermediates in a variety of reactions, but are generally prone to cyclization to give 2-amino-imidazoles. Here, we present a comprehensive analysis, based on experiments and quantum-chemical calculations, of the stability and reactivity of these compounds. It is shown that cyclization reactions are triggered by Brønsted and Lewis acids. The analysis discloses strategies allowing to prevent cyclization by careful choice of the guanidino group and/or substituent at the amino group. The results of this analysis allowed the synthesis of first unsymmetrical diguanidinobenzene molecules and coordination compounds with o-amino-guanidinobenzene ligands, paving the way for the development of aromatic compounds with adjacent amino and guanidino groups as a versatile class of redox-active organic molecules.
Beschreibung:Zuerst veröffentlicht: 12. Dezember 2025
Gesehen am 05.02.2026
Beschreibung:Online Resource
ISSN:1521-3765
DOI:10.1002/chem.202503147