title: Beyond the Divinyl Ketone: Innovations in the Generation and Nazarov Cyclization of Pentadienyl Cation Intermediates.
abstract: The requirement for new strategies for synthesizing five-membered carbocycles has driven an expansion in the study of the Nazarov cyclization. This renewed interest in the reaction has led to the discovery of several interesting new methods for generating the pentadienyl cation intermediate central to the cyclization. Methods reviewed include carbon-heteroatom ionization, functionalization of a double bond, nucleophilic addition, or electrocyclic ring opening. Additional variations employ unconventional substrates to produce novel pentacycles, such as the iso- and imino-Nazarov. Herein, we provide an overview of these unconventional, yet highly useful versions of the Nazarov cyclization.
authors.affiliation: Department of Chemistry, University of Rochester, RC Box 270216, Rochester, NY 14627.
authors.forename: William T
authors.initials: WT
authors.lastname: Spencer
authors.affiliation: Department of Chemistry and Chemical Biology, Cornell University Baker Laboratory Ithaca, NY 14853.
authors.forename: Tulaza
authors.initials: T
authors.lastname: Vaidya
authors.affiliation: Department of Chemistry, University of Rochester, RC Box 270216, Rochester, NY 14627.
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Frontier
keywords: Nazarov; carbocation; cyclopentane; electrocyclization; synthesis