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RESEARCH PRODUCT

Insights into the Mechanism of Anodic N–N Bond Formation by Dehydrogenative Coupling

Siegfried R. WaldvogelKevin D. MoellerTile GieshoffTile GieshoffDieter SchollmeyerAnton Kehl

subject

010405 organic chemistryDiradicalChemistryCationic polymerizationGeneral ChemistryBond formationBenzoxazole010402 general chemistryElectrochemistry01 natural sciencesBiochemistryCombinatorial chemistryCatalysis0104 chemical sciencesAnodechemistry.chemical_compoundColloid and Surface ChemistryOrganic chemistry

description

The electrochemical synthesis of pyrazolidine-3,5-diones and benzoxazoles by N-N bond formation and C,O linkage, respectively, represents an easy access to medicinally relevant structures. Electrochemistry as a key technology ensures a safe and sustainable approach. We gained insights in the mechanism of these reactions by combining cyclovoltammetric and synthetic studies. The electron-transfer behavior of anilides and dianilides was studied and led to the following conclusion: The N-N bond formation involves a diradical as intermediate, whereas the benzoxazole formation is based on a cationic mechanism. Besides these studies, we developed a synthetic route to mixed dianilides as starting materials for the N-N coupling. The compatibility with valuable functionalities like triflates and mesylates for follow-up reactions as well as the comparison of different electrochemical set-ups also enhanced the applicability of this method.

https://doi.org/10.1021/jacs.7b07488