2‐Substituted 3‐ethynylquinoxaline chromophores can be readily synthesized by a consecutive activation–alkynylation–cyclocondensation (AACC) one‐pot sequence in a three‐component manner. In comparison with the previously published four‐component glyoxylation starting from electron‐rich π‐nucleophiles, the direct activation of (hetero)aryl glyoxylic acids allows the introduction of substituents that cannot be directly accessed by glyoxylation. By introducing N,N‐dimethylaniline as a strong donor in the 2‐position, the emission solvatochromicity of 3‐ethynylquinoxalines can be considerably enhanced to cover the spectral range from blue–green to deep red–orange with a single chromophore in a relatively narrow polarity window. The diversity‐oriented nature of the synthetic multicomponent reaction concept enables comprehensive investigations of structure–property relationships by Hammett correlations and Lippert–Mataga analysis, as well as the elucidation of the electronic structure of the emission solvatochromic π‐conjugated donor–acceptor systems by DFT and time‐dependent DFT calculations with the PBEh1PBE functional for a better reproduction of the dominant charge‐transfer character of the longest wavelength absorption band.

中文翻译：

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三组分活化/炔基化/环缩合（AACC）合成增强的发射变色3-乙炔基喹喔啉

可以通过三组分的连续活化-炔基化-环缩合（AACC）一锅法序列轻松合成2-取代的3-乙炔基喹喔啉生色团。与以前发表的从富电子的π-亲核试剂开始的四组分乙醛酸化作用相比，（杂）芳基乙醛酸的直接活化作用允许引入不能被乙醛化作用直接取代的取代基。通过引入N，N由于二甲基苯胺是2-位的强供体，因此3-乙炔基喹喔啉的发射溶剂变色性可以得到显着增强，以单个生色团在相对窄的极性窗口内覆盖从蓝绿色到深红色橙色的光谱范围。合成多组分反应概念的多样性导向性质使得可以通过Hammett相关性和Lippert-Mataga分析对结构-性质关系进行全面研究，并通过DFT阐明发射溶剂化变色π-共轭供体-受体系统的电子结构。具有PBEh1PBE功能的时间依赖性DFT计算可更好地再现最长波长吸收带的主要电荷转移特征。