title: Homologation method for preparation of substituted pentacenes and naphthacenes.
abstract: Multi-substituted pentacenes, such as 1,2,3,4,6,8,9,10,11,13-decasubstituted pentacenes (Type I), 1,2,3,4,6,13-hexasubstituted pentacenes (Type II), 1,2,3,4-tetrasubstituted pentacenes (Type III), and 2,3-disubstituted pentacenes (Type IV), 1,2,3,4,6,11-hexasubstituted naphthacenes (Type V), 1,2,3,4-tetrasubstituted naphthacenes (Type VI), and 2,3-disubstituted naphthacenes (Type VII), were prepared by a homologation method. The homologation method involved the conversion of phthalic acid ester derivatives to two ring extended phthalic acid ester derivatives via diynes and metallacyclopentadienes using transition metals, such as Zr and Rh. For the formation of pentacenes of Type III and Type IV and naphthacenes of Type VII, trimethylsilyl-substituted diynes were used for zirconocene-mediated cyclization. Elimination of the trimethylsilyl groups after the cyclization afforded nonsubstituted position on pentacenes or naphthacenes. Structures of 1,4,6,8,9,10,11,13-octaethyl-2,3-bis(methoxycarbonyl)pentacene (9a) and 8,9,10,11-tetraethyl-2,3-bis(methoxycarbonyl)-1,4,6,13-tetrapropylpentacene (9b) were determined by X-ray analysis. The structure of 9a had the herringbone packing system in the crystal like nonsubstituted pentacene. However, 9b, whose substituents at 1,4,6,13-positions were changed from Et to Pr at 1,4,6,13-positions of 9a, had the face parallel plane system in the crystal.
authors.affiliation: Catalysis Research Center and Graduate School of Pharmaceutical Sciences, Hokkaido University, Japan. tamotsu@cat.hokudai.ac.jp
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Takahashi
authors.forename: Shi
authors.initials: S
authors.lastname: Li
authors.forename: Wenying
authors.initials: W
authors.lastname: Huang
authors.forename: Fanzhi
authors.initials: F
authors.lastname: Kong
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Nakajima
authors.forename: Baojian
authors.initials: B
authors.lastname: Shen
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ohe
authors.forename: Ken-ichiro
authors.initials: K
authors.lastname: Kanno
mesh_terms: D009279:Naphthacenes
chemical_list: D009279:Naphthacenes