Abstract: N-oxyphthalimides are stable and easily accessible compounds that can produce oxygen radicals upon 1-electron reduction. We present a systematic study of electrochemical properties of N-oxyphthalimide derivatives (PI-ORs) in DMF by cyclic voltammetry. In all cases, electron transfer to the substrate leads to decomposition of the intermediate radical anion via the N―O bond cleavage. In the case of benzyloxyphthalimide or its derivatives containing electron-donating substituents, reductive electron transfer induces the chain decomposition of the substrate to phthalimide (PI) radical-anion and the corresponding carbonyl compound. The PI radical-anion product is a powerful reductant that can transfer an electron to the reactant PI-OR, thus establishing a catalytic cycle for reductive N―O scission. This self-catalytic process is reflected in a considerable decrease in the reduction current for the substrate (<1e-/molecule). By contrast, reductive fragmentations of benzyl derivatives containing electron-withdrawing substituents in the aromatic ring or at the benzylic position, as well as tosyl and alkyl derivatives, occur via a 1-electron mechanism. A sequence of N―O and C―C scissions was engineered to support the intermediacy of O-centered radicals in these processes.

Cite: Syroeshkin M.A. , Krylov I.B. , Hughes A.M. , Alabugin I.V. , Nasybullina D.V. , Sharipov M.Y. , Gultyai V.P. , Terent'ev A.O.
Electrochemical behavior of N -oxyphthalimides: Cascades initiating self-sustaining catalytic reductive N ―O bond cleavage
Journal of Physical Organic Chemistry. 2017. V.30. N9. e3744 . DOI: 10.1002/poc.3744 WOS Scopus OpenAlex

Identifiers:

Web of science:	WOS:000409339500016
Scopus:	2-s2.0-85026650442
OpenAlex:	W2740319353

Citing:

DB	Citing
OpenAlex	49
Web of science	44
Scopus	42

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