The Biomimetic Synthesis of Polyarylated Fluorenes, Relevant to Selaginellaceae Polyphenols, Leading to the Spontaneous Formation of Stable Radicals

0583092 - ÚOCHB 2025 RIV US eng J - Journal Article
Nallappan, S. - Lapinskaite, R. - Hájíček, J. - Kunák, D. - Čambal, P. - Nečas, D. - Císařová, I. - Atalay, H. N. - Tumer, T. B. - Tarábek, Ján - Schwarzová-Pecková, K. - Rycek, L.
The Biomimetic Synthesis of Polyarylated Fluorenes, Relevant to Selaginellaceae Polyphenols, Leading to the Spontaneous Formation of Stable Radicals.
ChemPlusChem. Roč. 89, č. 4 (2024), č. článku e202300410. ISSN 2192-6506. E-ISSN 2192-6506
Institutional support: RVO:61388963
Keywords : selaginellacea polyphenols * biomimetic synthesis * radicals * spin density distribution * cytotoxicity
Impact factor: 3.4, year: 2022
Method of publishing: Open access
https://doi.org/10.1002/cplu.202300410

This work reports a biomimetic synthesis of polyarylated fluorene derivatives. The molecules are formed via intramolecular electrophilic aromatic substitution, resembling a cyclization leading towards the natural selaginpulvilins from selaginellins. The scope of the reaction was investigated, and the products were obtained in 60-95 % yields. Some of the compounds decompose to a stable radical. We investigated the nature and the origin of the radical using experimental methods, including EPR or electrochemical measurements, as well as theoretical methods, such as DFT calculations. Based on our observations, we hypothesize, that phenoxy radicals are formed in the first instance, which however undergo internal rearrangement to thermodynamically more stable carbon-centered radicals. The preliminary data also show the cytotoxic properties of some of the molecules.
Permanent Link: https://hdl.handle.net/11104/0351088