School of Chemical Sciences, Dublin City University, Dublin 9, Ireland.
J Org Chem. 2013 Mar 15;78(6):2355-61. doi: 10.1021/jo302448h. Epub 2013 Feb 13.
The reaction of isophthaloyl dichloride with 2-aminopyridine or 2-aminopyrimidine provides a facile entry into a new class of imide-based "3 + 3" macrocyclic trimer (trezimide), together with the known tetramer scaffold (tennimide). The trezimides can adopt two distinct asymmetric conformations in the solid state, isolated as (P) in (IO)3 (from 2-aminopyridine) and (R) in (26IO)3 (from 2-aminopyrimidine). The tennimide crystal structure (26IO)4 (from 2-aminopyrimidine) exhibits three discrete conformational states, highlighting subtle geometric changes with the tennimide channel (pore) open (o) and/or closed (c), as noted by three macrocycle conformations with their channel pores observed as cc/oc/oo. Macrocycle formation (though in competition with oligomer/polymer formation) relies on the o-pyr(im)idine N functionality and preorganized imide hinge (the "CO···CO" twist) together with the inherent flexibility of the isophthaloyl groups.
均苯二甲酰氯与 2-氨基吡啶或 2-氨基嘧啶反应，为一类新的基于酰亚胺的“3+3”大环三聚体（trezimide）提供了一条简便的合成途径，同时也得到了已知的四聚体支架（tennimide）。Trezimides 在固态中可以采取两种不同的不对称构象，分别为（P）在（IO）3（来自 2-氨基吡啶）和（R）在（26IO）3（来自 2-氨基嘧啶）中。Tennimide 晶体结构（26IO）4（来自 2-氨基嘧啶）表现出三种离散的构象状态，突出了随着 tennimide 通道（孔）打开（o）和/或关闭（c）而发生的微妙的几何变化，如通过观察到的三个大环构象及其通道孔来表示 cc/oc/oo。大环的形成（尽管与低聚物/聚合物的形成竞争）依赖于 o-吡啶（嘧啶）N 官能团和预组织的酰亚胺铰链（“CO···CO”扭曲）以及均苯二甲酰基的固有灵活性。
