title: Photochemistry of diethynyl sulfides: a cycloaromatization for the formation of five-membered rings.
abstract: The first five-membered ring cycloaromatization reaction has been demonstrated. Photoirradiation of bis(phenylethynyl) sulfide in hexanes/1,4-cyclohexadiene produces 3,4-diphenylthiophene through the presumed intermediacy of 2,5-didehydrothiophene. In addition, phenylacetylene is produced in this reaction consistent with competing direct carbon-sulfur cleavage. For reactions in ethanol or 2-propanol production of the thiophene is accompanied by the formation of phenylacetylene and a thionoester of the corresponding alcohol. Thiophene products also result from the irradiation of other diethynyl sulfides. [reaction: see text]
authors.affiliation: Department of Chemistry and the Macromolecular Science and Engineering Program, The University of Michigan, Ann Arbor, MI 48109-1055, USA.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Lewis
authors.forename: David L
authors.initials: DL
authors.lastname: Wenzler
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Matzger