使用K 2 CO 3作为碱,β-硝基苯乙烯与1,2-环己二酮的反应可形成高产率的3-芳基-5,6-二氢苯并呋喃-7(4 H)-。推定的反应机理包括将二酮C-烯酸酯最初迈克尔加成到β-硝基苯乙烯中,然后将所得的O-烯酸酯阴离子进行分子内环化,消除亚硝酸根离子和空气氧化。产物的形成高度依赖于基本化学计量。
Access to Substituted Carbazoles in Water by a One-Pot Sequential Reaction of α,β-Substituted Nitro Olefins with 2-(3-Formyl-1<i>H</i>-indol-2-yl)acetates
interesting new multifunctional carbazole scaffolds have been prepared in good to excellent yields by an organocatalytic one-pot two-step sequentialreaction between α-alkyl-β-substituted nitroolefins or α-alkyl-δ-substituted nitro-dienes and 2-(3-formyl-1H-indol-2-yl)acetates in water at room temperature followed by treatment with 2 n HCl under mild conditions. This one-pot, organocatalytic, oxidant-free