N-Methylated Diphenylguanidines: Conformations, Propeller-Type Molecular Chirality, and Construction of Water-Soluble Oligomers with Multilayered Aromatic Structures

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• 作者：Aya Tanatani ; Kentaro Yamaguchi ; Isao Azumaya ; Ryuuta Fukutomi ; Koichi Shudo ; and Hiroyuki Kagechika
• 刊名：Journal of the American Chemical Society
• 出版年：1998
• 出版时间：July 8, 1998
• 年：1998
• 卷：120
• 期：26
• 页码：6433 - 6442
• 全文大小：218K
• 年卷期：v.120,no.26(July 8, 1998)
• ISSN：1520-5126

文摘

The crystal structures ofN,N'-diphenylguanidine (1) and itsN-methylated derivatives wereinvestigated, and the conformational properties of these molecules wereutilized to construct water-solubleoligomers with multilayered aromatic structures.N,N'-Diphenylguanidine (1) afforded twotypes of crystals,chiral (P2₁2₁2₁) andracemic (P2₁/c), uponrecrystallization from EtOH. In both crystals, 1 existsin the (E,Z)conformation, in which one C-N bond (length: 1.28-1.30 Å)attached to a phenyl ring shows double-bondcharacter. In contrast,N,N'-dimethyl-N,N'-diphenylguanidine(4a) exists in the (Z,Z) conformationwith thetwo aromatic rings facing each other. As judged from the crystalstructures of several N-methylated compounds,the conformational preferences of diphenylguanidines appear to berelated to those of aromatic anilides.N,N,N',N''-Tetramethyl-N',N''-diphenylguanidiniumiodide (6) afforded chiral crystals, like 1 andN-methyl-N,N'-diphenylguanidine (2). The absolutestructure of each enantiomeric propeller conformation of 6wasdetermined by X-ray analysis using the Bijvoet difference method.The Z-conformational preference of4allowed us to synthesize oligomeric di- or tetraguanidines(9-12) which have multilayered aromaticstructuresboth as a crystal and in organic and aqueous solvents.