Synthesis of New Amphiphilic Dendrons Bearing Aliphatic Hydrocarbon Surface Sectors and a Monocarboxylic or Dicarboxylic Acid Focal Point
摘要:
[GRAPHICS]A new series of amphiphilic G1-G3 dendrons containing purely aliphatic hydrocarbon dendritic surface sectors and one or two carboxylic acid group(s) at the focal point was synthesized in good yields. The key branching steps involve diallylation reactions of diethyl malonate or Meldrum's acid. These dendrons are highly soluble in hexane despite having highly polar carboxylic acid groups at the focal point.
Structural Effects on the Catalytic, Emulsifying, and Recycling Properties of Chiral Amphiphilic Dendritic Organocatalysts
作者:Chui-Man Lo、Hak-Fun Chow
DOI:10.1021/jo9006128
日期:2009.8.7
was also found that higher product yields and enantioselectivities were obtained in the aldol reactions when the aromaticaldehyde contains an electron-withdrawing substituent. The catalysts could be recycled and reused five times without significant drop in product yields and enantioselectivities. In addition, cross product contamination was not found when the recovered G3 catalyst was subsequently
New Triazole-Containing Branched Bis(dipeptidomimetic) – Switching from Self-Dimerization to Anion-Binding Properties
作者:Tin-Ki Chui、Hak-Fun Chow
DOI:10.1055/s-0036-1590884
日期:2017.12
in chloroform. Job plot analysis, MALDI-TOF mass spectrometry, and NMR titration studies revealed a 1:1 binding stoichiometry with good binding affinities (K a ≈ 640–780 M–1). Structural studies using ROESY NMR spectroscopy and molecular modelling on the 2–DEP complex indicated the adoption of a helix-like conformation by the host with the guest situated near the branching juncture.
hydrocarbon‐based G1–G3 dendritic 2‐ureido‐4‐pyrimidinones (UPy) (S‐Gn)2 and (L‐Gn)2, differing from one another by the distance between the branching juncture to the urea end, were prepared and characterized. These hydrocarbon dendrons were also appended to a p‐aminonitrobenzene solvatochromic chromophore in order to probe their microenvironment polarity. While positive solvatochromism was observed which
基于脂族烃基的G1-G3树突状2‐脲基‐4‐嘧啶酮(UPy)(S‐G n)2和(L‐G n)2的两个系列,在分支结点到基点之间的距离互不相同。制备并表征了尿素端。这些烃树枝状分子也被附加到p-氨基硝基苯溶剂化发色团,以探测其微环境极性。尽管观察到了正溶剂溶剂变色,这表明生色团可接近溶剂,但是从G1到G3树突的微环境极性之间没有显着差异。通过1 H NMR光谱检查了树突状UPy衍生物的自组装行为和互变异构偏好。DDAA互变异构体的二聚常数(K dim *)在25和50°C的CDCl 3中在10 7 M -1不变,这与带有其他非极性取代基的UPy化合物相当。此外,K的下限(S-G n)2和(L-G n)2系列的DADA互变异构形式的dim *被确定分别为CDCl 3中的10 6和10 5 M -1。发现树突分支连接点与UPy单元的更近距离可导致对二聚态的去稳定作用。因此,(L-G n)2二聚体比(S-G
v. Braun; Kurtz, Chemische Berichte, 1937, vol. 70, p. 1224,1229
作者:v. Braun、Kurtz
DOI:——
日期:——
Synthesis of New Amphiphilic Dendrons Bearing Aliphatic Hydrocarbon Surface Sectors and a Monocarboxylic or Dicarboxylic Acid Focal Point
作者:Hak-Fun Chow、Ka-Fai Ng、Zhao-Yang Wang、Chun-Ho Wong、To Luk、Chui-Man Lo、Yu-Ying Yang
DOI:10.1021/ol0526928
日期:2006.2.1
[GRAPHICS]A new series of amphiphilic G1-G3 dendrons containing purely aliphatic hydrocarbon dendritic surface sectors and one or two carboxylic acid group(s) at the focal point was synthesized in good yields. The key branching steps involve diallylation reactions of diethyl malonate or Meldrum's acid. These dendrons are highly soluble in hexane despite having highly polar carboxylic acid groups at the focal point.