title: Two-Step Synthesis of Boron-Fused Double Helicenes.
abstract: Novel boron-fused double [5]helicenes were synthesized from hexabromobenzene in two steps via Hart reaction and demethylative cyclization. The parent helicene shows excellent ambipolar conductivity, which can be explained by unique 3D π-stacking with a brickwork arrangement. Moreover, the introduction of four tert-butyl groups suppresses racemization, enabling optical resolution. The enantiomerically pure helicene shows deep blue fluorescence with Commission Internationale de l'Eclairage coordinates of (0.15, 0.08) and circularly polarized luminescence activity.
authors.affiliation: Department of Chemistry, School of Science and Technology, Kwansei Gakuin University , 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan.
authors.forename: Takazumi
authors.initials: T
authors.lastname: Katayama
authors.affiliation: Department of Chemistry, School of Science and Technology, Kwansei Gakuin University , 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan.
authors.forename: Soichiro
authors.initials: S
authors.lastname: Nakatsuka
authors.affiliation: Department of Chemistry, School of Science and Technology, Kwansei Gakuin University , 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Hirai
authors.affiliation: Japan Synchrotron Radiation Research Institute (JASRI)/SPring-8 , 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Yasuda
authors.affiliation: Graduate School of Materials Science, Nara Institute of Science and Technology (NAIST) , 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
authors.forename: Jatish
authors.initials: J
authors.lastname: Kumar
authors.affiliation: Graduate School of Materials Science, Nara Institute of Science and Technology (NAIST) , 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kawai
authors.affiliation: Department of Chemistry, School of Science and Technology, Kwansei Gakuin University , 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan.|Elements Strategy Initiative for Catalysts and Batteries, Kyoto University , Katsura, Kyoto 615-8520, Japan.
authors.forename: Takuji
authors.initials: T
authors.lastname: Hatakeyama