A ruthenium(II)-catalyzed redox-free cycloaddition of N-sulfonyl aromatic aldimines with maleimides providing 1-aminoindanes in good yields is described. Usually, maleimides reacted with substituted aromatics, affording the Michael-type ortho alkylated aromatics or 1,1-type cyclized spirosuccinimides. In the present reaction, maleimides provided 1,2-type cycloaddition products. The proposed mechanism was strongly supported by the DFT calculations and isolation of a ruthenacycle intermediate.

中文翻译：

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钌（II）催化的N-磺酰基芳香醛亚胺与马来酰亚胺的无氧化还原[3 + 2]环加成反应

描述了钌（II）催化的N-磺酰基芳族醛亚胺与马来酰亚胺的无氧化还原的环加成，其以良好的产率提供了1-氨基茚满。通常，马来酰亚胺与取代的芳族化合物反应，得到迈克尔型邻烷基化的芳族化合物或1，1-型环化螺琥珀酰亚胺。在本反应中，马来酰亚胺提供了1，2-型环加成产物。拟议的机制得到DFT计算和钌环中间体中间体的分离的有力支持。