Zinc-Catalyzed Cyclization of Alkynyl Derivatives: Substrate Scope and Mechanistic Insights

Novel alkyl zinc complexes supported by acetamidate/thioacetamidate heteroscorpionate ligands have been successfully synthesized and characterized. These complexes exhibited different coordination modes depending on the electronic and steric effects of the acetamidate/thioacetamidate moiety. Their c...

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Detalles Bibliográficos
Autores: Martínez de Sarasa Buchaca, Marc, Gaona, Miguel A., Sánchez-Barba, Luis F., Garcés, Andrés, Rodríguez, Ana M., Rodríguez-Diéguez, Antonio, De la Cruz-Martínez, Felipe, Castro-Osma, José A., Lara Sánchez, Agustín
Tipo de recurso: artículo
Fecha de publicación:2024
País:España
Institución:Universidad de Castilla-La Mancha
Repositorio:RUIdeRA. Repositorio Institucional de la UCLM
OAI Identifier:oai:ruidera.uclm.es:10578/43255
Acceso en línea:https://doi.org/10.1021/acs.inorgchem.4c00832
https://hdl.handle.net/10578/43255
Access Level:acceso abierto
Palabra clave:Alcohols
Catalysts
Cyclization
Hydrocarbons
Zinc
Descripción
Sumario:Novel alkyl zinc complexes supported by acetamidate/thioacetamidate heteroscorpionate ligands have been successfully synthesized and characterized. These complexes exhibited different coordination modes depending on the electronic and steric effects of the acetamidate/thioacetamidate moiety. Their catalytic activity has been tested toward the hydroelementation reactions of alkynyl alcohol/acid substrates, affording the corresponding enol ether/unsaturated lactone products under mild reaction conditions. Kinetic studies have been performed and confirmed that reactions are first-order in [catalyst] and zero-order in [alkynyl substrate]. DFT calculations supported a reaction mechanism through the formation of the catalytically active species, an alkoxide-zinc intermediate, by a protonolysis reaction of the Zn–alkyl bond with the alcohol group of the substrate. Based on the experimental and theoretical results, a catalytic cycle has been proposed.