Intramolecular Photocycloaddition Reactions of Arylcyclopropane Tethered 1‑Cyanonaphthalenes

• Published in: Journal of organic chemistry Vol. 81; no. 18; pp. 8544 - 8551
• Main Authors: Maeda, Hajime, Matsuda, Shoji, Mizuno, Kazuhiko
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 16.09.2016; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Organic; Physical Sciences; Science & Technology; CYCLOPROPANE; ALKENES; ORGANIC-PHOTOCHEMISTRY; ELECTRON-TRANSFER; COMPLEXES; PHOTOEXCITATION; CLEAVAGE; META-PHOTOCYCLOADDITION
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/acs.joc.6b01721

Intramolecular photocycloaddition reactions of 1-cyanonaphthalenes bearing an arylcyclopropane containing side chain were investigated. Photoreactions of members of this family in which the arylcyclopropane moiety is bonded at the 2-position of the 1-cyanonaphthalene ring produce head-to-head and head-to-tail 1,2-[3+2] photocycloadducts. On the other hand, substances in this family containing an arylcyclopropane side chain linked to the 4-position of the cyanoarene ring undergo photoreactions to form [4+3] photocycloadducts along with novel nine-membered ring products, which are produced by photochemically induced 10π conrotatory ring opening of the initially formed intramolecular [3+2] cycloadducts. The results of solvent effects and fluorescence investigations along with those focusing on corresponding intermolecular photoreactions demonstrate that the photocycloadducts are formed predominantly through an intramolecular exciplex mechanism and that a photoinduced intramolecular electron transfer pathway via zwitterionic biradicals might be partly responsible for the process when CH3CN is the solvent.