Diverse Cyclization Pathways Between Nitriles with Active α-Methylene Group and Ambiphilic 2-Pyridylselenyl Reagents Enabled by Reversible Covalent Bonding DOI Open Access

Alexey A. Artemjev,

Alexander A. Sapronov, Alexey S. Kubasov

et al.

International Journal of Molecular Sciences, Journal Year: 2024, Volume and Issue: 25(23), P. 12798 - 12798

Published: Nov. 28, 2024

Herein, we describe a novel coupling between ambiphilic 2-pyridylselenyl reagents and nitriles featuring an active α-methylene group. Depending on the solvent employed, this reaction can yield two distinct types of cationic pyridinium-fused selenium-containing heterocycles, 1,3-selenazolium or 1,2,4-selenadiazolium salts, in high yields. This is contrast to what observed before for other nitriles. Notably, formation selenadiazolium reversible, gradually converting into more thermodynamically stable selenazolium product solution. Our findings reveal, first time, reversible nature 1,3-dipolar cyclization CN triple bond reagents. Nitrile substitution experiments adducts confirmed dynamic cyclization, indicating potential applications covalent chemistry. DFT calculations revealed mechanistic pathways new cyclizations, suggesting concerted [3 + 2] cycloaddition rings stepwise mechanism involving ketenimine intermediate rings. Natural orbital analysis involvement σ-hole interactions lone pair σ* electron donation these processes. Additionally, theoretical investigations were performed, focusing selenium-centered contacts within compounds.

Language: Английский

Diverse Cyclization Pathways Between Nitriles with Active α-Methylene Group and Ambiphilic 2-Pyridylselenyl Reagents Enabled by Reversible Covalent Bonding DOI Open Access

Alexey A. Artemjev,

Alexander A. Sapronov, Alexey S. Kubasov

et al.

International Journal of Molecular Sciences, Journal Year: 2024, Volume and Issue: 25(23), P. 12798 - 12798

Published: Nov. 28, 2024

Herein, we describe a novel coupling between ambiphilic 2-pyridylselenyl reagents and nitriles featuring an active α-methylene group. Depending on the solvent employed, this reaction can yield two distinct types of cationic pyridinium-fused selenium-containing heterocycles, 1,3-selenazolium or 1,2,4-selenadiazolium salts, in high yields. This is contrast to what observed before for other nitriles. Notably, formation selenadiazolium reversible, gradually converting into more thermodynamically stable selenazolium product solution. Our findings reveal, first time, reversible nature 1,3-dipolar cyclization CN triple bond reagents. Nitrile substitution experiments adducts confirmed dynamic cyclization, indicating potential applications covalent chemistry. DFT calculations revealed mechanistic pathways new cyclizations, suggesting concerted [3 + 2] cycloaddition rings stepwise mechanism involving ketenimine intermediate rings. Natural orbital analysis involvement σ-hole interactions lone pair σ* electron donation these processes. Additionally, theoretical investigations were performed, focusing selenium-centered contacts within compounds.

Language: Английский

Citations

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