title: Higher-order cyclization reactions of alkenyl Fischer carbene complexes: a new selective all-carbon [8 + 2] cyclization with 8-methoxyheptafulvene and computational mechanistic analysis.
abstract: A new higher-order cyclization reaction of alkenyl Fischer carbene complexes is described. Chromium and tungsten alkenyl Fischer carbene complexes react toward 8-methoxyheptafulvene through an all-carbon formal [8 + 2] cycloaddition reaction with complete regio- and stereoselectivity. Tetrahydroazulene compounds bearing four consecutive stereocenters are generated. The reaction mechanism is rationalized based on computational calculations. It was found that this transformation proceeds through a concerted process. The nature of the observed stereo- and regioselectivity can be attributed to both steric and electronic factors.
authors.affiliation: Instituto Universitario de Química Organometálica "Enrique Moles" and Departamento de Química Orgánica e Inorgánica, Universidad de Oviedo, Julián Clavería 8, 33071 Oviedo, Spain. alss@uniovi.es.
authors.forename: Jaime
authors.initials: J
authors.lastname: García-Rodríguez
authors.forename: Jairo
authors.initials: J
authors.lastname: González
authors.forename: Javier
authors.initials: J
authors.lastname: Santamaría
authors.forename: Ángel L
authors.initials: ÁL
authors.lastname: Suárez-Sobrino
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Rodríguez