Serial synthesis of oxa[3.n]cyclophanes and homooxacalix[n]arenes via reductive coupling of arenedialdehydes, and their X-ray structures†
作者:Naoki Komatsu、Takefumi Chishiro
DOI:10.1039/b102031p
日期:——
A wide range of oxa[3.n]cyclophanes and homooxacalix[n]arenes is prepared from the corresponding arenedialdehyde via reductive homocoupling reaction in a one-pot fashion. Heterocoupling reaction of arenedialdehyde with bis(trimethylsilyloxymethyl)benzene provides a series of macrocyclic ethers including a new type of oxacalixarene, which consists of the moieties of oxa[3.n]cyclophane and homooxacalix[n]arene; m- or p-phenylene, and 5-substituted 2-methoxy-m-phenylene are tethered by CH2OCH2 linkages. A series of macrocycles are separated with gel permeation chromatography (GPC) and identified with NMR (1H, 13C) and mass (MALDI-TOF) spectra. Their solid-state conformations are elucidated by X-ray crystallographic analyses.
通过还原性均偶联反应,以相应的戊二烯醛为原料,以一锅法制备出多种氧杂[3.n]环烷和均氧杂[n]烷。醛与双(三甲基硅氧基甲基)苯的异构偶联反应提供了一系列大环醚,其中包括一种新型氧杂喹喔啉,它由氧杂[3.n]环烷和均氧杂喹喔啉[n]炔的分子组成;间或对苯二酚和 5-取代的 2-甲氧基间苯二酚通过 CH2OCH2 链接。一系列大环通过凝胶渗透色谱法(GPC)进行分离,并通过核磁共振(1H、13C)和质谱(MALDI-TOF)进行鉴定。它们的固态构象通过 X 射线晶体学分析得以阐明。
Binding of Acetylcholine and Tetramethylammonium to Flexible Cyclophane Receptors: Improving on Binding Ability by Optimizing Host's Geometry
The structure of a cyclophanic tetraester (1), previously employed for investigations on the cation−πinteraction, has been optimized to better accommodate acetylcholine (ACh) and tetramethylammonium (TMA) guests. Following indications from molecular modeling calculations, a flexible cyclophane receptor of significantly improved binding properties has been obtained by removing the four carbonyl groups
先前用于研究阳离子-π相互作用的环烷四酸酯(1)的结构已进行了优化,以更好地容纳乙酰胆碱(ACh)和四甲基铵(TMA)来宾。根据分子模型计算的指示,已经通过除去母体宿主的四个羰基获得了结合性能显着改善的柔性环烷受体。通过改进的方法制备了2,11,20,29-四氧合[3.3.3.3]对环磷烷(2),该步骤经便利地设计以避免形成引起严重分离问题的连续的环寡聚物。协会2与TMA苦味酸盐是在CDCl测量3在Ť = 296 K内由1个1 H NMR滴定并与结合为一组参考主机获得的数据,包括父四酯1,相应的cyclophanic四胺,的开链对应物2,其从cyclooligomers五聚体八聚体到。通过主体的几何优化,实现了从15倍(相对于四酯和四胺)到超过80倍(相对于开链四醚)的结合增强。对于各种抗衡离子,研究了2与ACh和TMA的结合。恒定的结合近8千焦mol的自由能的增量- 1相对于1观察到,与