Institut für Chemie , Carl von Ossietzky Universität Oldenburg , 26111 Oldenburg , Germany.
J Org Chem. 2018 Apr 6;83(7):4002-4014. doi: 10.1021/acs.joc.8b00347. Epub 2018 Mar 19.
The 2,5-diaminoterephthalate structural motif is a powerful chromophore with remarkable fluorescence properties. Containing two carboxylate and two amino functions, it defines a colored molecular scaffold which allows for orthogonal functionalization with different functional units. Therefore, different applications in life sciences and materials science could be addressed. In this study, the two amino functions were alkylated by reductive amination with side chains carrying amino (orthogonally protected as Boc or Alloc) and carboxylate functions (orthogonally protected as tBu or allyl ester). After sequential deprotections, functional units were introduced by amidation reactions. As three examples, the chromophore was coupled with retinoic acid and fullerene C in order to obtain a triad for studying photoinduced electron transfer processes. Furthermore, cyclooctyne and azide moieties were introduced as functional units, allowing for ligation by click reactions. These two clickable groups were applied in combination with maleimide units which are reactive toward thiol residues. The latter dyes define so-called "turn on" probes, since the fluorescence quantum yields increased by one order of magnitude upon reaction with the molecular target.
2,5-二氨基对苯二甲酸结构基元是一种具有显著荧光性质的强色团。它含有两个羧酸盐和两个氨基官能团，定义了一个有色的分子支架，允许与不同的功能单元进行正交官能化。因此，可以解决生命科学和材料科学中的不同应用。在这项研究中，两个氨基官能团通过带有氨基（Boc 或 Alloc 保护）和羧酸盐官能团（tBu 或烯丙酯保护）的侧链进行还原胺化进行烷基化。经过顺序脱保护后，通过酰胺化反应引入功能单元。作为三个例子，色团与维甲酸和富勒烯 C 偶联，以获得用于研究光诱导电子转移过程的三联体。此外，还引入了环辛炔和叠氮基团作为功能单元，允许通过点击反应进行连接。这两个可点击基团与马来酰亚胺单元结合使用，马来酰亚胺单元对巯基残基具有反应活性。后一种染料定义为所谓的“开启”探针，因为与分子靶标反应后荧光量子产率增加了一个数量级。
