A novel ring expansion based on the readily available 2-azido-2-phenyl-indan-1,3-dione is described. Treatment with primary amines and cesium carbonate in a two-step sequence gives rise to 3-amino-2,3-dihydroisoquinoline-1,4-diones with an unprecedented substitution pattern. The corresponding conversion using amino acid methyl esters leads directly to a novel tricyclic 1,10a-dihydroimidazo-isoquinoline-2,5,10-trione scaffold, a structure that has never been reported before, to the best of our knowledge.

中文翻译：

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2-叠氮基-2-苯基-茚满-1,3-二酮的环扩展用于生成杂环支架。

描述了一种基于容易获得的2-叠氮基-2-苯基-茚满-1,3-二酮的新型环扩环。用伯胺和碳酸铯分两步进行处理，得到具有空前取代模式的3-氨基-2,3-二氢异喹啉-1,4-二酮。据我们所知，使用氨基酸甲酯的相应转化直接导致了新颖的三环1,10a-二氢咪唑基-异喹啉-2,5,10-三酮支架，该结构从未被报道过。