Abstract: The photochemical behavior of terarylenes bearing allomaltol and 2-aminooxazole fragments has been investigated, providing the basis for an efficient strategy toward substituted cyclopenta[b]quinoxalines. Upon irradiation of starting compounds with 400 nm visible light, the allomaltol moiety undergoes selectively ESIPT-induced contraction of the pyranone ring, affording highly reactive α-hydroxycyclopentene-1,2-dione intermediates, as evidenced by 1H NMR monitoring. Notably, the free amino group does not inhibit the photorearrangement, in contrast to related amino-substituted terarylenes. In situ trapping with 1,2-phenylenediamines affords cyclopenta[b]quinoxaline derivatives in yields of up to 87%, while phenylhydrazine gives separable E/Z hydrazones. The one-pot protocol proceeds under mild, metal- and base-free conditions.

Cite: Migulin A.V. , Migulin V.A. , Milyutin C.V. , Komogortsev A.N.
Photochemical Approach to Fused Quinoxaline Derivatives From Allomaltol‐Containing Terarylenes With 2‐Aminooxazole Bridge Fragment via Trapping of Unstable Cyclopentene‐1,2‐Dione Intermediates
Journal of Heterocyclic Chemistry. 2026. DOI: 10.1002/jhet.70232 WOS Scopus OpenAlex

Dates:

Submitted:	Jun 4, 2026
Accepted:	Aug 7, 2026
Published print:	Aug 20, 2026
Published online:	Aug 20, 2026

Identifiers:

≡ Web of science:	WOS:001853300600001
≡ Scopus:	2-s2.0-105047716979
≡ OpenAlex:	W7203763191

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