Related Experiment Video
Updated: Aug 16, 2025

Synthesis and Purification of Iodoaziridines Involving Quantitative Selection of the Optimal Stationary Phase for Chromatography
Published on: May 16, 2014
Synthesis of azafluoranthenes by iridium-catalyzed [2 + 2 + 2] cycloaddition and evaluation of their fluorescence
Takahiro Sawano1, Kaho Takamura1, Tomoka Yoshikawa1
1Department of Chemistry and Biological Science, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5258, Japan. takeuchi@chem.aoyama.ac.jp.
Abstract:
We report a method for the synthesis of azafluoranthenes under neutral reaction conditions in a highly atom-economical manner by the iridium-catalyzed [2 + 2 + 2] cycloaddition of 1,8-dialkynylnaphthalenes with nitriles. A variety of nitriles react with methyl- or phenyl-substituted 1,8-dialkynylnaphthalenes to give a wide range of azafluoranthenes. Azafluoranthenes bearing an amino group show intense fluorescence at around 500 nm. Comparison of the fluorescence properties of amine-substituted azafluoranthenes with related compounds revealed the importance of the amine moiety for obtaining a high fluorescence quantum yield. The choice of the solvent affected the emission maxima and the fluorescence quantum yield. Azafluoranthenes bearing pyrrolidine exhibited blue-shifted emission bands in a non-polar solvent and gave a fluorescence quantum yield of 0.76 in toluene. A Lippert-Mataga plot and computational studies provide insight into the origin of the fluorescence of azafluoranthenes. Furthermore, cellular experiments using human breast adenocarcinoma cells SK-BR-3 demonstrated the feasibility of using azafluoranthenes as fluorescent probes.
Related Concept Videos
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
Cycloaddition Reactions: Overview
Variables Affecting Phosphorescence and Fluorescence
Atomic Fluorescence Spectroscopy

![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)