title: Rhodium-Catalyzed Synthesis and Optical Properties of Silicon-Bridged Arylpyridines.
abstract: A convergent and regioselective synthesis of silicon-bridged 4-arylpyridines has been developed through a rhodium-catalyzed [2+2+2] cycloaddition of silicon-containing diynes with nitriles. The absorption and emission properties of these compounds have been examined and could be tuned by varying the substituent on the benzene ring, as well as through the protonation or alkylation of the nitrogen atom on the pyridine ring. A catalytic asymmetric synthesis of silicon-centered axially chiral spirocyclic derivatives has also been achieved with high enantioselectivity by using a newly modified MeO-MOP (MeO-MOP=2-(diphenylphosphino)-2'-methoxy-1,1'-binaphthyl) derivative as the chiral ligand. These spirocyclic compounds were found to be CPL-active (CPL=circularly polarized luminescence), representing the first CPL-active compounds based on the chirality at silicon.
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Shintani
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
authors.forename: Nana
authors.initials: N
authors.lastname: Misawa
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Takano
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Nozaki
keywords: asymmetric catalysis; circularly polarized luminescence; fluorescence; rhodium; π-conjugated compound