Acetylene vs ketones on the route to base-promoted assembly of furans or 6,8-dioxabicyclo[3.2.1]octanes and cyclopentenols: a quantum-chemical study

Autor: V B Orel, N M Vitkovskaya
Rok vydání: 2021
Předmět:
Zdroj: Journal of Physics: Conference Series. 1847:012056
ISSN: 1742-6596
1742-6588
DOI: 10.1088/1742-6596/1847/1/012056
Popis: The electronic characteristics of substrates (α,β-unsaturated ketones) and reagents (carbanions of ketones and ethynide ions), as well as thermodynamic and kinetic characteristics both their interaction and the formation of final products have been evaluated using the B2PLYP/6-311+G**//B3LYP/6-31+G* and B3LYP/6-311++G**//B3LYP/6-31+G* quantum-chemical approaches. Reactivity indices that adequately describe the electrophilic and nucleophilic properties of the substrates and reagents are proposed. It has been shown that, regardless of the nature of substrates and reagents, the formation of cyclopentenols and furans is thermodynamically favorable, while the presence of bulky substituents leads to an increase in energy during the formation of 6,8-dioxabicyclo[3.2.1]octanes and explains in this case their absence in products. The calculated activation barriers of the competing reactions of the nucleophilic addition of ethynide ions and ketone carbanions to the double C=C bond of α,β-unsaturated ketones are correlated with the observed reaction direction and the proposed reactivity indices.
Databáze: OpenAIRE