Hydrogen-Bonding-Mediated Anthranilamide Homoduplexes. Increasing Stability through Preorganization and Iterative Arrangement of a Simple Amide Binding Site
摘要:
This paper describes the assembly of two new series of self-complementary duplexes by making use of amide units, the simplest assembling units of hydrogen bonding, as binding sites. All the new monomers possess a rigidified anthranilamide skeleton, which is stabilized by intramolecular hydrogen bonding. Amide units are iteratively introduced to one side of the preorganized skeletons to facilitate the formation of intermolecular hydrogen bonding. Compounds 2 and 3 bear two and three CONH2 units, respectively, while 4, 6, and 7 are incorporated with two, three, and four AcNH units, respectively. For comparison, compound 5, which is similar to 4 but contains one AcNH and one CF3CONH unit, is also prepared. X-ray diffraction analysis of 2, 4, and 5 revealed homodimeric motifs in the solid state which are stabilized by two or more intermolecular hydrogen bonds. H-1 NMR investigations in CDCl3 indicated that all the compounds form hydrogen-bonded homoduplexes. Duplexes 3(.)3, 6(.)6, and 7(.)7 are highly stable in CDCl3, with a lower K-assoc limit of 2.3 x 10(5) M-1. The K-assoc values of the three duplexes in more polar CDCl3/CD3CN (9:1, v/v) were determined with the H-1 NMR dilution method. The result opens the way for the development of new polymeric duplexes of well-ordered structures.
Hydrogen-Bonding-Mediated Dynamic Covalent Synthesis of Macrocycles and Capsules: New Receptors for Aliphatic Ammonium Ions and the Formation of Pseudo[3]rotaxanes
作者:Xiao-Na Xu、Lu Wang、Gui-Tao Wang、Jian-Bin Lin、Guang-Yu Li、Xi-Kui Jiang、Zhan-Ting Li
DOI:10.1002/chem.200900309
日期:2009.6.2
Dynamiccovalentsynthesis! Intramolecular hydrogen‐bonding induces amino‐ and aldehyde‐appended aryl amides to adopt a rigid “V”‐shaped conformation. As a result, stable two‐layered capsules can be assembled quantitatively through the one‐step formation of six imine bonds. The newcapsules form complexes with aliphatic diammonium ions to give unique two‐layered pseudo[3]rotaxanes (see figure).
Hydrogen bonding-mediated self-assembly of anthranilamide-based homodimers through preorganization of the amido and ureido binding sites
作者:Jiang Zhu、Jian-Bin Lin、Yun-Xiang Xu、Xi-Kui Jiang、Zhan-Ting Li
DOI:10.1016/j.tet.2006.09.073
日期:2006.12
Tbe self-assembly of a novel series of hydrogen bonding-mediated homodimers in chloroform-d has been described. Six anthranilamide-based monomers have been prepared, in which two self-binding formamido, trifluoroacetamido, acetamido, butyl or methyl ureido units are introduced at the two ends of the backbones. Quantitative H-1 NMR investigations in chloroform-d revealed that the formamido and ureido units are more efficient than acetamido to induce the formation of stable homodimers. The association constants of all the new homodimers have been determined by H-1 NMR dilution method. Multiply hydrogen bonding-driven binding patterns have been proposed for the homodimers. It is also found that ureido-derived homodimers do not adopt common linear binding pattern observed for simple urea derivatives. (c) 2006 Elsevier Ltd. All rights reserved.