Yb(NTf2)3-catalyzed [3 + 3] cycloaddition between isatin ketonitrones and cyclopropanes is described. A variety of spiro[tetrahydro-1,2-oxazine]oxindoles were obtained in moderate to good yields along with good regioselectivities. This is the first example of the intermolecular [3 + 3] cycloaddition between ketone-derived nitrones and cyclopropanes.
描述了 Yb(NTf2)3 催化的
靛红酮硝酮和
环丙烷之间的 [3 + 3] 环加成反应。以中等至良好的产率和良好的区域选择性获得了多种螺[四氢-1,2-恶嗪]
吲哚。这是酮衍生的硝酮和
环丙烷之间分子间[3 + 3]环加成的第一个例子。