title: Stereochemical Investigation of the Products of the Photoinduced Perfluoroalkylation-Dimerization of Anthracene.
abstract: The photoinduced perfluoroalkylation of anthracene has been shown to provide 9,9',10,10'-tetrahydro-10,10'-diperfluoroalkyl-9,9'-bianthracenes in over 70% yields, each perfluoroalkyl iodide producing three diastereomers. The structures of all three diastereomers (cis,cis, cis,trans, and trans,trans isomers) have been elucidated by both NMR and X-ray crystallographic analyses. Most notably, an X-ray crystallographic analysis has revealed that the trans,trans diastereomer having the two trifluoromethyl groups in 10,10'-positions adopts a 74° twisted relationship of the two dihydroanthracene rings. Furthermore, each of the two trans,trans isomers 2a,b has been shown to exist as a mixture of new types of atropisomers and the energy barrier for the interconversion of the two atropisomers has been estimated to be 12 kcal/mol by variable-temperature NMR analysis.
authors: Department of Chemistry, Ochanomizu University , 2-1-1, Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan.
authors: Emiko
authors: E
authors: Nogami
authors: Division of Applied Chemistry, Institute of Engineering, Tokyo University of Agriculture and Technology , 2-24-16 Nakamachi, Koganei, Tokyo 184-8588, Japan.
authors: Takashi
authors: T
authors: Yamazaki
authors: Department of Biomolecular Functional Engineering, Ibaraki University , 4-12-1 Nakanarusawa, Hitachi 316-851, Japan.
authors: Toshio
authors: T
authors: Kubota
authors: Department of Chemistry, Ochanomizu University , 2-1-1, Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan.
authors: Tomoko
authors: T
authors: Yajima
mesh_terms: D000478:Alkylation; D000873:Anthracenes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019281:Dimerization; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D000873:Anthracenes; D006845:Hydrocarbons, Fluorinated