Mocilac Pavle, Gallagher John F
School of Chemical Sciences, Dublin City University, Dublin 9, Ireland.
Acta Crystallogr B. 2013 Feb;69(Pt 1):62-9. doi: 10.1107/S0108768112047416. Epub 2012 Dec 20.
The one-step reaction of isophthaloyl dichloride with the 2-aminopyridine derivative (methyl 6-aminonicotinate) yields (i) a trimer-based macrocycle (EsIO)(3) and (ii) a tetramer-based macrocycle (EsIO)(4) in modest isolated synthetic yields (total of 25%), together with (iii) longer open-chain oligomers. The macrocyclization relies on the semi-flexible imide hinge formed by reaction of the 2-amino(pyridine) functional group with two acyl chloride functional groups. The determining factors in macrocycle synthesis are: (a) imide formation using the heteroaromatic ortho-N functionality; (b) the inherent ability of the imide to twist by 85-115° from planarity (as measured by the CO···CO imide torsion angles), thereby providing a hinge for macrocyclic ring closure or potentially (non)helical assembly in oligomer/polymer formation; (c) the conformational flexibility of the isophthaloyl group with meta-related carbonyl groups to twist and adopt either syn or anti conformations, although the syn conformation is observed structurally for all isophthaloyl groups in both (EsIO)(3) (trezimide) and (EsIO)(4) (tennimide) macrocycles.
间苯二甲酰二氯与2-氨基吡啶衍生物（6-氨基烟酸甲酯）的一步反应，以适度的分离合成产率（总计25%）生成了（i）基于三聚体的大环化合物(EsIO)(3)和（ii）基于四聚体的大环化合物(EsIO)(4)，同时还生成了（iii）更长的开链低聚物。大环化反应依赖于由2-氨基（吡啶）官能团与两个酰氯官能团反应形成的半柔性酰亚胺铰链。大环化合物合成中的决定因素包括：（a）利用杂芳环邻位-N官能团形成酰亚胺；（b）酰亚胺从平面扭转85 - 115°的固有能力（通过CO···CO酰亚胺扭转角测量），从而为大环闭环或在低聚物/聚合物形成中潜在的（非）螺旋组装提供铰链；（c）间苯二甲酰基团与间位相关羰基的构象灵活性，使其能够扭转并采取顺式或反式构象，尽管在(EsIO)(3)（曲酰亚胺）和(EsIO)(4)（替尼酰亚胺）大环化合物中所有间苯二甲酰基团在结构上均观察到顺式构象。
