Modular Synthesis of π-Acceptor Cyclophanes Derived from 1,4,5,8-Naphthalenetetracarboxylic Diimide and 1,5-Dinitronaphthalene
作者:Guoying Chen、John T. Lean、Monica Alcalá、Thomas E. Mallouk
DOI:10.1021/jo991054y
日期:2001.5.1
bonding interactions with guest molecules. Despite the fact that these cyclophanes contain a hydrophobic binding cavity of appropriate dimensions, their association with indole is very weak. In the case of cyclophanes derived from 1,5-dinitronaphthalene, steric interactions force the nitro groups out of the plane of the naphthalene ring, diminishing their effectiveness as pi-acceptors. A simple UV--visible
合成了三个中性环烷,并研究了它们与芳族π供体吲哚的缔合。环烷被设计为包含刚性疏水结合腔,其中1,4,5,8-萘四甲酸二酰亚胺或1,5-二硝基萘为π受体。两个环烷还包含(S)-(缬氨酸-亮氨酸-丙氨酸)三肽单元,以提供与客体分子的手性氢键相互作用。尽管事实上这些环烷包含适当尺寸的疏水结合腔,但是它们与吲哚的缔合非常弱。在衍生自1,5-二硝基萘的环烷的情况下,空间相互作用迫使硝基脱离萘环的平面,降低了它们作为pi-受体的效力。一种简单的UV-可见滴定法,使用N,N,N',N' 用π-四甲基-1,4-苯二胺(TMPD)作为pi供体,对这些和其他芳族单元的pi受体强度进行排名。这些滴定表明,1,4,5,8-萘四甲酸二酰亚胺和1,5-二硝基萘衍生物是比紫精更弱的pi-受体,它们构成良好的pi-受体环烷。甲基紫精反过来比蒽醌二磺酸盐更弱的pi受体,这表明后者可能是pi接受的环戊烷宿主的有用组成部分。