Pyridinium-Fused 1,3-Selenazoles via Cyclizations of 2-Pyridylselenyl Chloride with Alkynes: Synthesis, Structures, and Antifungal Properties
Year: 2026
Type: article
Abstract: We report a straightforward and versatile synthetic route to pyridinium-fused 1,3-selenazoles via the electrophilic cyclization of 2-pyridylselenyl chloride with alkynes. The reaction proceeds efficiently under mild conditions with representative terminal and internal alkynes. While the cyclization exhibits high regioselectivity favoring the 3-substituted isomer for most substrates, reactions with 2-pyridyl- and 2-quinolylacetylenes yield regioisomeric mixtures. DFT calculations rationalize this divergence, revealing a competition between kinetic and thermodynamic control; the 3-isomer is kinetically favored, while the 2-isomer is thermodynamically stabilized by an ancillary chalcogen bond between the selenium atom and the pyridine nitrogen of the alkyne substituent. Molecular structures were confirmed by single-crystal X-ray diffraction, and the non-covalent interactions governing supramolecular assembly in the solid state were rigorously analyzed using MEP surfaces, the QTAIM, and NBO analysis. Antifungal evaluation identified several compounds with notable activity against phytopathogenic fungi, highlighting the potential of this novel heterocyclic scaffold in agrochemical applications.
DOI: 10.3390/ijms27062908
Institutions: Peoples' Friendship University of Russia, Russian Academy of Sciences, NS Kurnakova Institute of General and Inorganic Chemistry, A. N. Nesmeyanov Institute of Organoelement Compounds, N.D. Zelinsky Institute of Organic Chemistry, Nizhny Novgorod State Technical University, Wuhan University of Technology, State Key Laboratory of Advanced Technology For Materials Synthesis and Processing, Universitat de les Illes Balears, Xi'an Jiaotong University
Language: English
Subfield: Toxicology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,499
Award: G2594994207
OpenAlex ID: W7140128005