title: FeCl3-Mediated Oxidative Spirocyclization of Difluorenylidene Diarylethanes Leading to Dispiro[fluorene-9,5'-indeno[2,1-a]indene-10',9''-fluorene]s.
abstract: A novel FeCl3-mediated oxidative spirocyclization for construction of a new class of di-spirolinked π-conjugated molecules, dispiro[fluorene-9,5'-indeno[2,1-a]indene-10',9''-fluorene]s (DSFIIFs), has been reported. The combination of FeCl3 with FeO(OH) triggered an unprecedented double one-electron oxidation of difluorenylidene diarylethanes to afford the corresponding dispirocycles in high yields. The highest fluorescence quantum yield was up to 0.94 in solution. This protocol is also applicable to the synthesis of the non-spirolinked dihydroindenoindenes.
authors.affiliation: WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1, Aoba-ku Katahira, Sendai 980-8577 (Japan).
authors.forename: Jian
authors.initials: J
authors.lastname: Zhao
authors.affiliation: WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1, Aoba-ku Katahira, Sendai 980-8577 (Japan).
authors.forename: Zhanqiang
authors.initials: Z
authors.lastname: Xu
authors.affiliation: WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1, Aoba-ku Katahira, Sendai 980-8577 (Japan).
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Oniwa
authors.affiliation: WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1, Aoba-ku Katahira, Sendai 980-8577 (Japan).
authors.forename: Naoki
authors.initials: N
authors.lastname: Asao
authors.affiliation: WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1, Aoba-ku Katahira, Sendai 980-8577 (Japan).|State Key Laboratory of Fine Chemicals and School of Chemistry, Dalian University of Technology, Dalian 116023 (China).
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Yamamoto
authors.affiliation: WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1, Aoba-ku Katahira, Sendai 980-8577 (Japan). tjin@m.tohoku.ac.jp.
authors.forename: Tienan
authors.initials: T
authors.lastname: Jin
keywords: conjugation; fluorescence; materials science; oxidation; spirocompounds