5,6-Bis(dimethylamino)acenaphthylene as an activated alkene and ‘proton sponge’ in halogenation reactions
作者:Maxim A. Mekh、Valery A. Ozeryanskii、Alexander F. Pozharskii
DOI:10.1016/j.tet.2006.10.008
日期:2006.12
by the steric bulk of the entering halogen and then by solvent polarity thus allowing the regioselective preparation of 1(2)- or 4(7)-(di)halides. Introduction of the third and fourth bromine atoms, but not chlorine, is accomplished by mono-N-demethylation. The pKa values of some new derivatives of acenaphthene and acenaphthylene proton sponges were measured by competitive transprotonation 1H NMR spectroscopy
已经表明5,6-双(二甲基氨基)ac乙烯在与X 2(X = Cl,Br,I)和N -X-琥珀酰亚胺的反应中同时表现为富电子的烯烃或芳烃和质子海绵。因此,向C(1)C(2)键中添加溴或碘,然后立即进行脱卤化氢反应,从而以高收率形成了相应的1(2)-(di)卤代ena烯。与氯的反应仅能分离出1,4,7-三氯-5,6-双(二甲基氨基)th。与N-卤代琥珀酰亚胺,卤化主要由进入的卤素的空间体积决定,然后由溶剂极性决定,因此可以区域选择性地制备1(2)-或4(7)-(二)卤化物。通过单-N-去甲基化完成第三和第四溴原子而不是氯的引入。通过竞争性转质子化1 H NMR光谱技术在DMSO中测量ena啶和new烯质子海绵的一些新衍生物的p K a值。报道了4,7-二氯-5,6-双(二甲基氨基)ac的X射线分子结构及其单质子化形式。