作者:Alexandru C. Razus、Carmen Nitu、Simona Carvaci、Liviu Birzan、Stefan A. Razus、Mihaela Pop、Laszlo Tarko
DOI:10.1039/b100007l
日期:——
N-(Azulen-1-ylmethylene)arylamines, 5, were obtained in a fast quantitative conversion and high yield from the condensation of the corresponding azulene-1-carbaldehydes with aromatic amines without solvent. The reactions of the Schiff bases obtained, 5, were compared to those of the corresponding azo compounds 1a which have already been studied. The lack of regioselectivity in the oxidation of 5 with anhydrous FeCl3 at both the azulenyl and at the aryl moiety, in contrast with the oxidation of compounds 1a which react mainly at the aryl, is in agreement with the differences of the calculated Fukui one electron reactivity index squared (IR2) for the reactive positions in these molecules. From the calculated net charge for different positions in the molecules, a regioselective course for the electrophilic halogenation with CuCl2 for both compounds 1a and 5 (at C3 in the azulene moiety) can be foreseen. However, the Schiff bases were chlorinated also at the aromatic ring; an explanation was proposed for this behaviour.
相应的偶氮烯-1-羰基醛与芳香胺在无溶剂条件下进行缩合,可快速定量、高产地获得 N-(偶氮烯-1-亚甲基)芳基胺 5。获得的希夫碱 5 的反应与已经研究过的相应偶氮化合物 1a 的反应进行了比较。5 与无水 FeCl3 的氧化反应在偶氮烯基和芳基上都缺乏区域选择性,而化合物 1a 的氧化反应则主要在芳基上发生,这与计算出的这些分子中反应位置的福井一个电子反应性指数平方(IR2)的差异是一致的。根据计算得出的分子中不同位置的净电荷,可以预见化合物 1a 和 5(在偶氮烯分子中的 C3 处)与 CuCl2 的亲电卤化反应具有区域选择性。然而,希夫碱在芳香环上也被氯化了;对这种行为提出了解释。