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Updated: Sep 19, 2025

Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization
Published on: November 29, 2018
Ring Cleavage for Ring Construction: Oxidative Heterocyclic Segregation toward Tribenzophenanthrolines
Takanori Suzuki1, Kota Asai1, Takeru Saito1
1Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan.
Abstract:
Intramolecular double C─N bond formation followed by deselenylation enables a one-pot skeletal editing of selenadiazole-fused naphthoquinodimethanes into previously unknown tribenzophenanthroline derivatives, which serve as precursors to fluorescent metal complexes. This transformation involves the disappearance of the original selenadiazole ring containing two nitrogen atoms and the concurrent formation of two new pyridine rings, each containing a single nitrogen atom. This "heterocyclic segregation (Het-Seg)" reaction is triggered by two-electron oxidation of sterically congested quinodimethane substrates with a folded geometry. The resulting twisted dicationic intermediates are crucial for driving the unique skeletal reorganization.
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