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Synthetic Routes to Novel Fluorogenic Pyronins and Silicon Analogs with Far-Red Spectral Properties and Enhanced Aqueous Stability

submitted on 31.03.2020 and posted on 02.04.2020 by Garance Dejouy, Kévin RENAULT, Ibai E. Valverde, Anthony ROMIEU
Fluorogenic detection of reactive (bio)analytes is often achieved with "smart" probes, whose activation mechanism causes the release of aniline-based fluorophores. Indeed, the protection-deprotection of their primary amino is the simplest way to induce dramatic and valuable changes in spectral features of the fluorogenic reporter. In this context, and due to their small size and intrinsic hydrophilicity, we focused on pyronin dyes and related heteroatom analogs (i.e., formal derivatives of 3-imino-3H-xanthen-6-amine and its silicon analog) for their use as optically tunable aniline-based fluorophores. To overcome some severe limitations associated with the use of such fluorogenic scaffolds (i.e., poor aqueous stability and spectral features only in the green-yellow spectral range), the synthesis of novel unsymmetrical derivatives of (Si)-pyronins bearing a single bulky tertiary aniline (i.e., N-methylindoline and julolidine) was explored and presented in this Article. This structural alteration has been found to be beneficial to dramatically lower electrophilicity of the meso-position and to reach attractive fluorescence properties within the far-red spectral region.


Butyrylcholinesterase-based fluorescent and/or colorimetric detection of organophosphorus nerve agents – DetectOP_BChE

Agence Nationale de la Recherche

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Email Address of Submitting Author


Univ. Bourgogne Franche-Comté



ORCID For Submitting Author


Declaration of Conflict of Interest

No conflict of interest

Version Notes

Version 1 31.03.2020