title: Reacting cyclopropenones with arynes: access to spirocyclic xanthene-cyclopropene motifs.
abstract: A formal insertion of two aryne moieties into the carbon-oxygen double bond of cyclopropenone has been realized. Spirocyclic xanthene-cyclopropene scaffolds were obtained. Mechanistically, a sequence of a formal [2 + 2]-cycloaddition followed by electrocyclic ring opening and a terminating [4 + 2]-type cycloaddition is postulated. The use of an electron-rich aryne precursor led to ring cleavage of the cyclopropene to afford an unprecedented xanthylium salt.
authors.forename: Jan
authors.initials: J
authors.lastname: Wallbaum
authors.affiliation: †Technische Universität Braunschweig, Institut für Anorganische Chemie, Hagenring 30, 38106 Braunschweig, Germany.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Jones
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Werz