title: Elaboration of diaryl ketones into naphthalenes fused on two or four sides: a naphthoannulation procedure.
abstract: Transition metal-catalyzed double ring closures of 1,1-diaryl-2,2-diethynylethylenes yield polycyclic aromatic hydrocarbons and heterocycles that contain a newly formed naphthalene ring system embedded in a larger polycyclic network. The diynes required for this procedure are readily synthesized from diaryl ketones by the Corey-Fuchs olefination and subsequent Sonogashira coupling with trimethylsilylacetylene followed by desilylation. This procedure provides easy access to new compounds such as 3,11-di-tert-butyl[4]helicene and 1,8,9-perinaphthothioxanthene. Double naphthoannulation of 9,10-anthraquinone by this procedure closes four new benzene rings in a single operation to give coronene, although the yield in this case is presently low.
authors.affiliation: Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467-3860, USA.
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Donovan
authors.forename: Lawrence T
authors.initials: LT
authors.lastname: Scott