2-(Guanidiniocarbonyl)furans as a New Class of Potential Anion Hosts: Synthesis and First Binding Studies
作者:Carsten Schmuck、Uwe Machon
DOI:10.1002/ejoc.200600324
日期:2006.10
The synthesis of a new class of potential anion hosts, the 2-(guanidiniocarbonyl)furans 5a–d, is presented in this study. The facile decomposition of furans under acidic conditions makes the synthesis of these compounds challenging. First binding studies showed that the (guanidiniocarbonyl)furans are much more acidic (pKa ≈ 5.5) than the analogous pyrroles (pKa ≈ 7) previously introduced by us for
本研究介绍了一类新的潜在阴离子宿主 2-(胍基羰基)呋喃 5a-d 的合成。呋喃在酸性条件下的容易分解使得这些化合物的合成具有挑战性。第一次结合研究表明,(胍基羰基)呋喃比我们之前引入的用于在水性溶剂中结合氧阴离子的类似吡咯(pKa ≈ 7)酸性更强(pKa ≈ 5.5)。因此,阴离子与呋喃衍生物的结合仅在低于 pH = 5 的酸性溶液中发生。因此,羧酸盐不能有效结合,而例如,碱性较弱的硫酸氢盐与 5b 结合,结合常数为 K = 600 M– 1 在含水 DMSO 中,即使存在大量过量的缓冲液。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)