Department of Chemistry, Lomonosov Moscow State University, 119899 Moscow, Russia.
Molecules. 2023 Jun 16;28(12):4822. doi: 10.3390/molecules28124822.
Modification of 5-aryl-4-trifluoroacetyltriazoles at the NH-moiety was investigated. Screening of the alkylation conditions revealed that using NaCO as a base and DMF as a solvent of 2-substituted triazoles can be preferentially prepared in up to 86% yield. In the best cases, the amount of minor 1-alkyl isomer was less than 6%. SAr reaction of the 5-aryl-4-trifluoroacetyltriazoles with aryl halides having electron-withdrawing groups led to regiospecific formation of 2-aryltriazoles isolated in good-to-high yields. Chan-Lam reaction of the 5-aryl-4-trifluoroacetyltriazoles with boronic acids afforded 2-aryltriazoles as single isomers in up to 89% yield. The subsequent reaction of the prepared 2-aryltriazoles with primary and secondary amines gave a set of amides of 4-(2,5-diaryltriazolyl)carboxylic acid. The fluorescent properties of the prepared 2-substituted derivatives of triazoles were investigated to demonstrate their utility as new efficient luminophores having more than 60% quantum yields.
对 5-芳基-4-三氟乙酰基三唑的 NH 部分进行了修饰研究。通过筛选烷基化条件发现，使用 NaCO3 作为碱，DMF 作为溶剂，可以优先制备高达 86%收率的 2-取代三唑。在最佳情况下，少量 1-烷基异构体的含量小于 6%。5-芳基-4-三氟乙酰基三唑与具有吸电子基团的芳基卤化物的 SAr 反应导致 2-芳基三唑以高区域选择性形成，收率良好至高产率。5-芳基-4-三氟乙酰基三唑与硼酸的 Chan-Lam 反应以高达 89%的收率得到 2-芳基三唑作为单一异构体。随后，所制备的 2-芳基三唑与伯胺和仲胺反应得到了一组 4-(2,5-二芳基三唑基)羧酸酰胺。研究了所制备的三唑 2-取代衍生物的荧光性质，以证明它们作为具有超过 60%量子产率的新型高效发光体的用途。
