Merkt Franziska K, Pieper Konstantin, Klopotowski Maximilian, Janiak Christoph, Müller Thomas J J
Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany.
Institut für Anorganische Chemie und Strukturchemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany.
Chemistry. 2019 Jul 17;25(40):9447-9455. doi: 10.1002/chem.201900277. Epub 2019 Apr 9.
3-Triazolylquinoxalines can be readily synthesized by applying two complementary synthetic protocols starting from heterocyclic π nucleophiles or (hetero)aryl glyoxylic acids in a consecutive four- or five-component reaction. Conceptually, the sequential use of a single cuprous salt for alkynylation and Cu-catalyzed alkyne-azide cycloaddition (CuAAC) in a one-pot fashion sets the stage for activation-alkynylation-cyclocondensation-CuAAC or glyoxylation-alkynylation-cyclocondensation-CuAAC sequences in good yields. The diversity-oriented generation of differently substituted 3-triazolylquinoxalines is an excellent entry to tunable emission solvatorchromic fluorophores with triazole ligation. The electronic structure, corroborated by DFT and TD-DFT calculations, rationalizes the charge transfer character of relevant absorptions and large Stokes shifts as well as the electronic innocence of the triazole substituents.
通过应用两种互补的合成方案，从杂环π亲核试剂或（杂）芳基乙醛酸开始，在连续的四组分或五组分反应中，可以很容易地合成3-三唑基喹喔啉。从概念上讲，以一锅法顺序使用单一亚铜盐进行炔基化和铜催化的炔基-叠氮环加成反应（CuAAC），为活化-炔基化-环缩合-CuAAC或乙醛酸化-炔基化-环缩合-CuAAC序列奠定了基础，产率良好。以不同方式取代的3-三唑基喹喔啉的多样化生成是通向具有三唑连接的可调发射溶剂化显色荧光团的绝佳途径。通过DFT和TD-DFT计算证实的电子结构，合理化了相关吸收的电荷转移特性、大斯托克斯位移以及三唑取代基的电子中性。
