title: [4.2](2,2')(2,2')Biphenylophanetriyne: a twisted biphenylophane with a highly distorted diacetylene bridge.
abstract: Biphenylophane 1 bridged by acetylene and diacetylene linkages was synthesized. X-ray analysis revealed its highly deformed diacetylene unit with a bond angle of 160°. Enantiomers of 1 resolved by chiral HPLC underwent facile racemization with an activation energy of 90.6 kJ mol(-1). Transannular cyclization of 1 was induced by heating to generate benzyne intermediate 8, which was intercepted by furan to give 9, and by treatment with bromine to give dibromodibenzopicene (10).
authors.affiliation: Division of Frontier Materials Science, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka 560-8531, Japan.
authors.forename: Shunpei
authors.initials: S
authors.lastname: Nobusue
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamane
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Miyoshi
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Tobe