Bieniek JC, Grünewald M, Winter J, Schollmeyer D, Waldvogel SR.
Electrochemical Synthesis of
N
,
N
’‑
Disubstituted Indazolin-3-ones via Intramolecular Anodic DehydrogenativeN-NCoupling Reaction.
Chem Sci 2022;
13:8180-8186. [PMID:
35919432 PMCID:
PMC9278119 DOI:
10.1039/d2sc01827f]
[Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 06/10/2022] [Indexed: 11/30/2022] Open
Abstract
The use of electricity as a traceless oxidant enables a sustainable and novel approach to N,N′-disubstituted indazolin-3-ones by an intramolecular anodic dehydrogenative N–N coupling reaction. This method is characterized by mild reaction conditions, an easy experimental setup, excellent scalability, and a high atom economy. It was used to synthesize various indazolin-3-one derivatives in yields up to 78%, applying inexpensive and sustainable electrode materials and a low supporting electrolyte concentration. Mechanistic studies, based on cyclic voltammetry experiments, revealed a biradical pathway. Furthermore, the access to single 2-aryl substituted indazolin-3-ones by cleavage of the protecting group could be demonstrated.
A novel sustainable electrochemical synthetic route to N,N′-disubstituted indazolin-3-ones by direct anodic oxidation with mild reaction conditions, a simple galvanostatic setup, broad scope and excellent scalability is established.![]()
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