摘要以亚烷基三唑为轴基,以四氢芴基为封端基,采用螺纹封端法制备了具有不同烷基链长度的客体分子的偶氮苯桥联支柱[5]芳烃基[3]轮烷。通过高分辨率质谱,1 H NMR和NOESY光谱证明了柱[5]芳烃的包封。通过用365 nm和蓝光LED辐射合成的[3]轮烷,分别引起反式至顺式和顺式至反式异构化,检查了光响应特性。辐照没有柱[5]芳烃包封的相应模型客体化合物导致几乎完全反式转化为顺式和顺式为反式异构化,这表明柱[5]芳烃的存在是确定的光异构化效率的决定因素。
Sweet switches: azobenzene glycoconjugates synthesized by click chemistry
作者:Vijayanand Chandrasekaran、Thisbe K. Lindhorst
DOI:10.1039/c2cc33542e
日期:——
Azobenzene glycoconjugates can be switched between two isomeric states, E and Z, to change the spatial orientation of the conjugated carbohydrate ligands. Mono-, di- and trivalent azobenzene glycoconjugates were synthesized using click chemistry and their photochromic properties determined. Multivalency effects were observed in photoisomerisation.
Peptoids, or poly-N-substituted glycines, are characterised by broad structural diversity. Compared to peptides, they are less restricted in rotation and lack backbone-derived H bonding. Nevertheless, certain side chains force the peptoid backbone into distinct conformations. Designable secondarystructures like helices or nanosheets arise from this knowledge. Herein, we report the copper-catalysed
Synthesis of β-cyclodextrin derivatives functionalized with azobenzene
作者:Juan M. Casas-Solvas、Manuel C. Martos-Maldonado、Antonio Vargas-Berenguel
DOI:10.1016/j.tet.2008.08.098
日期:2008.11
Two approaches for the synthesis of beta-cyclodextrin and bis(beta-cyclodextrin) bearing azobenzene on the primary face are reported. First, the nucleophilic substitution of mono-6-tosyl-beta-cyclodextrin by azobenzene anion derivatives was reinvestigated and found to produce mono-3,6-anhydro-beta-cyclodextrin as a side product. A slight modification of the reported reaction conditions including the use of Cs2CO3 led to a substantial improvement of the yields. In addition, a convenient method based on the application of click chemistry led to 1,2,3-triazole-linked azobenzene-cyclodextrin derivatives in good yields. (C) 2008 Elsevier Ltd. All rights reserved.