A series of thiourea and guanidinium derivatives have been prepared and their ability to bind a carboxylate group has been investigated. Guanidinium 33, featuring two additional amides and a pyridine moiety, proved to be the most potent carboxylate binding site and was able to bind acetate in aqueous solvent systems (Kass = 480 M−1 in 30% H2O–DMSO). The pyridine moiety is critical to obtaining strong binding, and comparison with the binding properties of analogous compounds in which the pyridine is replaced by a benzene ring provides a striking example of enthalpy–entropy compensation.
我们制备了一系列
硫脲和
胍衍
生物,并研究了它们与羧基结合的能力。
胍33具有两个额外的酰胺和一个
吡啶基,被证明是最有效的羧基结合位点,能够在
水性溶剂体系中结合
醋酸盐(30%
H2O-
DMSO 中的 Kass = 480 M-1)。
吡啶分子是获得强结合力的关键,将其与
吡啶被苯环取代的类似化合物的结合特性进行比较,是焓熵补偿的一个显著实例。