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Updated: Jan 13, 2026

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Published on: July 17, 2020

ヒドロキノン/キノンサイクルによる還元的光触媒変換

Iida Alanko¹, Anna Lenarda¹, Xinyu Bao¹

¹Department of Chemistry, University of Helsinki, 00014 Helsinki, Finland.

Organic letters

|January 8, 2026

Abstract:

Phenanthrenehydroquinones (H₂PQs), generated in situ from phenanthrenequinones under visible light using alcohols as hydrogen sources, act as catalytic organic photoreductants. They deoxygenate efficiently diverse N-heterocyclic N-oxides, including substrates having more negative reduction potentials than the H₂PQ excited-state reduction potential ( $E_{H_{2} {P Q}^{+ \cdot} / H_{2} {P Q}^{*}}$ = -2.10 V vs SCE), suggesting hydrogen bonding assisted electron transfer. TD-DFT calculations indicate H₂PQs act as both photoacids and photoreductants. This work demonstrates the harnessing of the hydroquinone/quinone cycle in visible-light-driven reductions.

キーワード:

光還元脱酸素化 N-オキシドヒドロキノンキノン光触媒有機化学フェナントレン

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