An efficient and environment-friendly method was developed to construct 7H-Chromeno[3,2-c]quinolin-5-ium Salts through metal-free cascade intermolecular reaction. Then the resulting quinolinium salts could serve as synthons and be further transformed to diverse synthetically useful 3-(2-hydroxy-benzoyl)quinolin-4-ones in water. This protocol offers a simple cascade strategy to synthesize a wide variety of natural-like quinolinium salts and quinolin-4-ones.

中文翻译：

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通过 3-甲酰色酮和苯胺的酸促进级联反应高效合成 7H-Chromeno[3,2-c]quinolin-5-ium 盐和 Quinolin-4-ones

开发了一种通过无金属级联分子间反应构建 7 H -Chromeno[3,2-c]quinolin-5-ium 盐的高效环保方法。然后所得的喹啉鎓盐可以用作合成子，并在水中进一步转化为各种合成有用的 3-(2-羟基-苯甲酰基)喹啉-4-酮。该协议提供了一种简单的级联策略来合成各种天然类喹啉盐和 quinolin-4-ones。