AbstractBrønsted acid mediated [3+2] cycloaddition of coumarin‐based enamines with 3‐ylidene oxindoles generated in situ from 3‐hydroxy‐3‐aroylmethyl oxindoles enabled the synthesis of polyheterocyclic compounds with a pyrrolocoumarin core structure in a highly regioselective manner. The synthetic procedure is highly efficient and metal‐free, and no chromatographic purification of the products is required. The chromenopyrrole derivatives bearing an oxindole moiety formed as rapidly interconverting rotamers.
摘要勃氏酸介导的香豆素基烯胺与 3- 亚基氧吲哚的[3+2]环加成反应原位生成了 3- 羟基-3-芳酰基甲基氧吲哚,从而以高度区域选择性的方式合成了以吡咯香豆素为核心结构的多杂环化合物。合成过程高效且不含金属,无需对产物进行色谱纯化。带有吲哚分子的铬吡咯衍生物能迅速形成相互转化的旋转体。