Chiral Rodlike Platinum Complexes, Double Helical Chains, and Potential Asymmetric Hydrogenation Ligand Based on "Linear" Building Blocks: 1,8,9,16-Tetrahydroxytetraphenylene and 1,8,9,16-Tetrakis(dip

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• 作者：Hai-Yan Peng ; Chi-Keung Lam ; Thomas C. W. Mak ; Zongwei Cai ; Wai-Tang Ma ; Yu-Xue Li ; and Henry N. C. Wong
• 刊名：Journal of the American Chemical Society
• 出版年：2005
• 出版时间：July 6, 2005
• 年：2005
• 卷：127
• 期：26
• 页码：9603 - 9611
• 全文大小：568K
• 年卷期：v.127,no.26(July 6, 2005)
• ISSN：1520-5126

文摘

This paper is concerned with the synthesis of 1,8,9,16-tetrahydroxytetraphenylene (3a) via copper(II)-mediated oxidative coupling, its resolution to optical antipodes, and its conversion to 1,8,9,16-tetrakis(diphenylphosphino)tetraphenylene (3b). On the basis of these chiral "linear" building blocks, three rodlikechiral complexes, triblock (R,R,R,R)-17 and (S,S,S,S)-20 and pentablock (R,R,R,R,R,R,R,R)-22, wereconstructed. As a hydrogen bond donor, racemic and optically active 3a was allowed to assemble withlinear acceptors to afford highly ordered structures. A 1:1 adduct of 4,4'-bipyridyl and (±)-3a exists in adimeric form of 3a linked by 4,4'-bipyridyl through hydrogen bonds. Pyrazine serves as a short linker betweenachiral parallel chains each formed by (±)-3a, while self-assembly of homochiral 3a into alternate parallelchains occurs in the adduct of 5,5'-dipyrimidine with (±)-3a. Self-assembly of (S,S)-3a or (R,R)-3a with4,4'-dipyridyl yielded a packing of chiral double helical chains formed by chiral tetrol 3a molecules. A novelchiral ligand, (S,S)-23, derived from 3a was used in the asymmetric catalytic hydrogenation of mages/gifchars/alpha.gif" BORDER=0>-acetamidocinnamate, yielding up to 99.0% ee and 100% conversion.