Variously substituted 2‐vinylpyrroles underwent an endo‐addition [4+2] cycloaddition reaction with maleimides followed by a spontaneous highly diastereoselective (93–98% de) isomerization to give tetrahydroindoles in moderate to excellent yield. Treatment with activated MnO2 in refluxing toluene provided the corresponding indoles in moderate to good yield. This highly convergent methodology for formation
各种取代的2-
乙烯基吡咯与马来
酰亚胺进行内加成[4 + 2]环加成反应,然后自发地高度非对映选择性(93-98%de)异构化,得到中等至优异收率的四氢
吲哚。在回流的
甲苯中用活化的MnO 2处理以中等至良好的产率提供了相应的
吲哚。这种高度收敛的
吲哚形成方法是通用的,并且可以方便地制备起始原料。J.杂环化学,(2009)。