title: Ring-closing metathesis reactions on azinium salts: straightforward access to quinolizinium cations and their dihydro derivatives.
abstract: The ring-closing metathesis reaction of 1-butenyl-2-vinylpyridinium salts and 2-butenyl-1-vinylpyridinium salts using Grubbs second generation and Hoveyda-Grubbs catalysts proved to be an efficient approach to 3,4-dihydro- and 1,2-dihydroquinolizinium salts and the corresponding quinolizinium derivatives by an improved thermal oxidation in the presence of Pd/C without solvent. A comparative study showed that the quinolizinium system was obtained in better yields through the 3,4-dihydroquinolizinium route, thus allowing the synthesis of quinolizinium derivatives or improvements in the yields of some examples reported previously.
authors.affiliation: Departamento de Química Orgánica, Universidad de Alcalá, 28871-Alcalá de Henares, Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Nuñez
authors.forename: Beatriz
authors.initials: B
authors.lastname: Abarca
authors.forename: Ana M
authors.initials: AM
authors.lastname: Cuadro
authors.forename: Julio
authors.initials: J
authors.lastname: Alvarez-Builla
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Vaquero