Synthesis of 5-Heteroaryl- and 5,7-Bis(heteroaryl)azulenes by Electrophilic Substitution of 1,3-Di-tert-Butylazulene with Triflates of N-Containing Heterocycles
of Tf 2 O under milder reaction conditions. Treatment of the 5-(dihydroheteroaryl)azulene derivatives with KOH readily gave the desired 5-(heteroaryl)azulene derivatives. Unexpectedly, N-(5-azulenyl)pyridinium triflate 17 was also obtained by the reaction of 1 with (trifluoromethylsulfonyl)pyridinium trifluoromethanesulfonate (TPT). 5-Heteioaryl- and 5,7-bis-(heteroaryl)azulene derivatives exhibited
首次建立了 5-杂芳基和 5,7-双(杂芳基)芘衍生物的高效合成方法。在过量杂环存在下,反应通过 1,3-二叔丁基芘 (1) 与含 N 杂环的三氟甲磺酸酯的亲电取代进行,收率良好。假定的中间体 5-(二氢杂芳基)-芘衍生物也可通过与几个含 N 杂环在 Tf 2 O 存在下在较温和的反应条件下反应而获得。用 KOH 处理 5-(二氢杂芳基) 芴衍生物很容易得到所需的 5-(杂芳基)芴衍生物。出乎意料的是,通过 1 与(三氟甲基磺酰基)吡啶鎓三氟甲磺酸盐(TPT)的反应,也获得了 N-(5-莰基)吡啶鎓三氟甲磺酸盐 17。5-杂芳基-和5,由于分子内电荷转移 (CT) 吸收带的发展,7-双-(杂芳基)芘衍生物在乙酸中比在二氯甲烷中表现出显着的颜色变化。通过循环伏安法 (CV) 和微分脉冲伏安法 (DPV) 检查这些新的薁衍生物的氧化还原行为。