Chromene substructure is an important structural motif present in a variety of medicines, natural products, and materials showing biological activities. Here, a simple and convenient procedure for the synthesis of 3,4‐dihydropyrano[3,2‐c]chromene derivatives is described. For this purpose, Fe₃O₄ nanoparticles supported on β‐cyclodextrin‐guanidine were successfully prepared and used as catalyst. The structure of this catalyst was assigned by Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, thermal gravimetric analysis, and vibrating sample magnetometer techniques. The prepared nanocomposites were used as a highly active, heterogeneous, and reusable nanocatalyst for the one‐pot, three‐component reaction of 4‐hydroxycoumarin, aromatic aldehydes, and ethyl cyanoacetate. This method has advantages such as mild conditions, high yields, easy workup and simple purification of products, little catalyst loading, cost efficiency, and reusability of the catalyst.

中文翻译：

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设计，制备和表征Fe3O4纳米颗粒，其中包含β-环糊精的胍是一种高效且可重复使用的非均相碱催化剂，用于合成3,4-二氢吡喃并[3,2-c]苯二酚

ne烯亚结构是存在于多种具有生物活性的药物，天然产物和材料中的重要结构基序。在这里，描述了一种简单而方便的合成3,4-二氢吡喃并[3,2- c ]色烯衍生物的方法。为此，将Fe ₃ O ₄纳米颗粒负载在β上环糊精胍已成功制备并用作催化剂。该催化剂的结构通过傅里叶变换红外光谱，X射线衍射，扫描电子显微镜，热重分析和振动样品磁力计技术进行分配。制备的纳米复合材料可用作高活性，多相和可重复使用的纳米催化剂，用于4-羟基香豆素，芳族醛和氰基乙酸乙酯的一锅，三组分反应。该方法具有条件温和，收率高，产品易于后处理和纯化简单，催化剂负载少，成本效率高和催化剂可重复使用等优点。