Volume 2013, Issue 28 p. 6310-6316
Full Paper

Redox-Active Triazolium-Derived Ligands in Nucleophilic Fe-Catalysis – Reactivity Profile and Development of a Regioselective O-Allylation

Johannes E. M. N. Klein

Johannes E. M. N. Klein

Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany

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Michael S. Holzwarth

Michael S. Holzwarth

Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany

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Stephan Hohloch

Stephan Hohloch

Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34–36, 14195 Berlin, Germany

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Biprajit Sarkar

Biprajit Sarkar

Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34–36, 14195 Berlin, Germany

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Bernd Plietker

Bernd Plietker

Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany

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First published: 08 August 2013
Citations: 29

Graphical Abstract

Triazolium-derived N-heterocyclic carbene ligands, generated by deprotonation of corresponding triazolium salts, are versatile ligands in diverse allylic substitution reactions. The corresponding triazolium salts are zwitterionic in their liberated form and act as strong redox-active σ-donor ligands thus enabling an unprecedented Fe-catalyzed regioselective aryloxylation of allylic carbonates.

Abstract

Triazolium-derived N-heterocyclic carbene (aNHC) ligands, which are readily accessible by deprotonation of the corresponding triazolium salts, proved to be versatile ligands in diverse allylic substitution reactions. The corresponding triazolium salts are formed from azides and alkynes through the application of 1,3-dipolar cycloaddition and N-alkylation reactions. The unique property of these ligands is to be zwitterionic in their liberated form and to act as strong redox-active σ-donor ligands. By virtue of these qualities, these ligands enable the development of an unprecedented Fe-catalyzed regioselective aryloxylation of allylic carbonates.