Polycationic oligo(chiral bicyclic guanidines) constitute useful non-peptidic penetrating agents for cell uptake and protein surface recognition. We report herein improved and selective procedures for the preparation of oligoguanidinium scaffolds linked through thioether bonds, with similar or different groups and functions at both ends of the chain. Two synthetic strategies were developed to obtain these compounds in relatively good yields from a common thioacetate precursor: generation of a disulfide intermediate or thiolate formation. Thus, tetraguanidinium intermediates 8 and 22 are best synthesized by the disulfide route, whereas hexamer 29, octamer 31, and trimer 37 arise from a combination of both the disulfide and the thioacetate routes. Finally, tetramer 28 can be readily obtained from either strategy.
多阳离子寡(手性双环
胍)是一种有用的非肽渗透剂,可用于细胞吸收和蛋白质表面识别。我们在此报告了通过
硫醚键连接的低聚
胍基支架的改进和选择性制备程序,这些支架在链的两端具有相似或不同的基团和功能。为了从常见的
硫代乙酸酯前体中以相对较高的产率获得这些化合物,我们开发了两种合成策略:生成二
硫化物中间体或形成
硫代
硫酸盐。因此,四
胍中间体 8 和 22 最好通过二
硫途径合成,而六聚体 29、八聚体 31 和三聚体 37 则通过二
硫途径和
硫代乙酸途径的组合产生。最后,四聚体 28 可以很容易地通过这两种途径获得。