Axial chirality of N,N′-disubstituted 3,4-ethylenedioxythiophene-2,5-dicarboxamides
作者:Ivana Stolić、Krešimir Molčanov、Goran Kovačević、Biserka Kojić-Prodić、Miroslav Bajić
DOI:10.1007/s11224-011-9885-x
日期:2012.4
A series of N,N’-disubstituted 3,4-ethylenedioxythiophene-2,5-dicarboxamides was synthesised by amide bond formation between 3,4-ethylenedioxythiophene-2,5-dicarbonyl chloride and corresponding primary amines, where the size and the nature of the substituent were varied. The crystal structures of prepared compounds were determined by X-ray structure analysis. Mechanism and reaction rates of interconversion between conformational isomers were obtained by DFT calculations. All studied compounds reveal axial chirality with molecular symmetry C 2. Amide bond isomerisation and twisting of the dioxane ring in studied compounds results in the formation of series of conformers of which the s-trans/s-trans conformer is energetically most favourable.
通过3,4-乙撑二氧噻吩-2,5-二甲酰氯与相应的伯胺之间形成酰胺键合成了一系列N,N'-二取代的3,4-乙撑二氧噻吩-2,5-二甲酰胺,其中尺寸和性质取代基不同。通过X射线结构分析确定了所制备化合物的晶体结构。通过DFT计算得到了构象异构体之间相互转化的机理和反应速率。所有研究的化合物都显示出具有分子对称性 C 2 的轴向手性。研究的化合物中酰胺键异构化和二恶烷环的扭曲导致形成一系列构象异构体,其中 s-trans/s-trans 构象异构体在能量上最有利。