betaine subunit(s). These typify the first example of simple cyclophanes constructed out of both highly pi-excessive and highly pi-deficient heteroaromatic moieties linked in a 1,3-alternating fashion. The chemical reactivity of the quadrupolar heterophanes 1a and 1c toward electrophiles under neutral conditions corroborated their bis-betaine structure. The structural features of the bis-betaines 1
在事先选择用于构建四极杂物框架的
甜菜碱结构单元后,报道了一种收敛的“ 3 + 1”合成策略,用于合成由杂环
甜菜碱亚基组成的标题大环。这些代表了由以1,3-交替方式连接的高度pi过量和高度pi不足的杂芳族部分构成的简单环烷的第一个例子。在中性条件下,四极杂物1a和1c对亲电试剂的
化学反应证实了它们的双
甜菜碱结构。通过1H和13C NMR光谱和电喷雾电离质谱研究了双
甜菜碱1,
甜菜碱2 x PF6和5 x X以及相应的双官能[1(4)]杂三烷3 x 2X和4 x 2Cl的结构特征,