title: Expanding the chemical space for push-pull chromophores by non-concerted [2+2] and [4+2] cycloadditions: access to a highly functionalised 6,6-dicyanopentafulvene with an intense, low-energy charge-transfer band.
abstract: Non-concerted [2+2] and [4+2] cycloadditions between N,N-dimethylanilino-substituted 1,1,2,4,4-pentacyanobuta-1,3-diene and 4-ethynyl-N,N-dimethylaniline are controlled by solvent polarity and provide access to a highly functionalised 6,6-dicyanopentafulvene featuring an intense, low-energy charge-transfer band and to an unusual spirocyclic zwitterion, characterised by X-ray analysis.
authors.affiliation: Laboratorium für Organische Chemie, ETH Zürich, Hönggerberg, HCI, 8093 Zürich, Switzerland.
authors.forename: Govindasamy
authors.initials: G
authors.lastname: Jayamurugan
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Gisselbrecht
authors.forename: Corinne
authors.initials: C
authors.lastname: Boudon
authors.forename: Franziska
authors.initials: F
authors.lastname: Schoenebeck
authors.forename: W Bernd
authors.initials: WB
authors.lastname: Schweizer
authors.forename: Bruno
authors.initials: B
authors.lastname: Bernet
authors.forename: François
authors.initials: F
authors.lastname: Diederich