Affiliation:
1. Departamento de Química Orgánica I University of the Basque Country (UPV/EHU) and Donostia International Physics Center (DIPC) P° Manuel Lardizabal 3 20018 Donostia/San, Sebastián Spain
2. IKERBASQUE Basque Foundation for Science E-48013 Bilbao Spain
Abstract
AbstractThe relevance of solvent molecules in the reactivity of alkyne cations has been analyzed computationally. Analysis of the possible reaction mechanisms towards competitive cyclization and elimination processes including a molecule of solvent shows the crucial role of the solvent. In dichloromethane there are no relevant discrete solvent‐cation interactions that could determine the outcome and a strong intramolecular π‐cation interaction favors the [5‐exo‐dig] cyclization route. On the other hand, in tetrahydrofuran or toluene solvated environments, the existence of solvent‐cation interaction via formation of a dative C−O bond or the formation of a highly stabilized triflate‐cation complex, respectively, modifies the energy profile, thus promoting the elimination pathway.