Chloride Selective Macrocyclic Bisurea Derivatives with 2,2′-Binaphthalene Moieties as Spacers
作者:Akira Satake、Yuki Ishizawa、Hiroshi Katagiri、Shin-ichi Kondo
DOI:10.1021/acs.joc.6b01959
日期:2016.10.21
A cyclic bisurea derivative 2a has been successfully prepared from the corresponding diamine and diisocyanate in the presence of tetrabutylammonium chloride as a template. A more soluble cyclic bisurea 2b has also been prepared by introduction of sterically bulky tert-butyl groups. X-ray crystal analyses of [2a·Cl]− and [2b·Cl]− revealed that overall structure was saddle like and the chloride anion
在四丁基氯化铵作为模板的情况下,由相应的二胺和二异氰酸酯已成功制备了环状双氨基甲酸酯衍生物2a。还已经通过引入空间上大体积的叔丁基基团来制备了更具溶解性的环状双脲2b。对[ 2a ·Cl] -和[ 2b ·Cl] -的X射线晶体分析表明,整体结构呈马鞍状,氯离子位于空腔中心。结合的氯阴离子通过四个NH脲基与氢键结合,并且通过四个1-CH萘基与氢键结合。除去[ 2b·Cl] -用硝酸银,得到两种不同的游离2b的X射线晶体;一种是分子间氢键收缩结构,另一种是延伸结构。受体2B显示出大的结合能力氯- ,然而,对于氯的选择性-对碱性阴离子,如ACO -和F - ,一直不足。在MeCN水溶液中,Cl –的缔合常数降低了2b,但仍然很大,疏水性Cl –的选择性大大提高了。在这种溶剂中,2b还选择性地识别出碱金属氯化物盐。因此,环状比苏拉2b是高度选择性和有效的Cl –选择性受体。