Brønsted acid-catalyzed cyclization reactions of N-alkyl anilines with alkynes or alkenes in the presence of oxygen gas as an oxidant under metal- and solvent-free conditions are described. Various quinoline derivatives are obtained in satisfactory to excellent yields. Different groups, such as methyl, fluoro, chloro, bromo, methoxy, and ester linked on benzene rings, are tolerated under optimized reaction conditions.

中文翻译：

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N烷基苯胺和炔烃或烯烃的布朗斯台德酸催化的无金属和无溶剂喹啉合成

描述了在无金属和无溶剂条件下，在氧气作为氧化剂存在下，布朗斯台德酸催化的N-烷基苯胺与炔烃或烯烃的环化反应。以令人满意的至优异的产率获得了各种喹啉衍生物。在优化的反应条件下，可以容忍不同的基团，例如在苯环上连接的甲基，氟，氯，溴，甲氧基和酯。