Aims: Novel bi metal organic framework (b–MOF) is synthesized and used as a heterogeneous catalyst for the synthesis of chromeno[4, 3–b]quinolone derivatives via one-pot and solvent-free, four-component reaction of dimedone, aromatic aldehydes, 4–hydroxycoumarin and ammonium acetate at 110°C.

Background: b–MOFs can be used as a heterogeneous catalyst in the synthesis of many organic compounds. The active and multi-purpose sites in b–MOFs provide a varied function in their catalytic applications. In this paper, reductive CES method is applied for the synthesis of Ce_0.47/Ni_0.53–BTC b–MOF. The resulting b–MOF was used as a heterogeneous catalyst for the synthesis of chromeno[4, 3–b]quinolone via one-pot and solvent-free, fourcomponent reaction of dimedone, aromatic aldehyde, 4–hydroxycoumarin and ammonium acetate at 110 °C.

Method: Ce_0.47/Ni_0.53–BTC was synthesized in an electrochemical cell composed of a stainless steel foil with a size of 5cm×5cm centered between two 5cm×5cm sized graphite plates as the anodes by the cathodic current density of 0.2 A/dm² and placed in a solution of cerium nitrate (0.3 g), nickel nitrate (0.3 g), H₃BTC (0.2 g) and NaNO₃ (0.1 g) in ethanol (500 mL). Ce_0.47/Ni_0.53–BTC (10 mg) was added to a mixture of dimedone (1 mmol), aromatic aldehyde (1 mmol), hydroxycoumarin (1 mmol) and ammonium acetate (1.5 mmol) and stirred at 110 °C under solvent-free conditions for 45 min. The reaction evolution was controlled by the TLC (hexane:ethyl acetate, 4:1). Then, boiling ethanol was added to the reaction mixture and stirred at room temperature for 15 min. After the reaction completion, the catalyst was separated by centrifuge. Finally, the reaction mixture was placed in an ice bath, which resulted in a white solid product and recrystallized from ethanol to give the pure product.

Result: The b–MOF catalyst showed very good efficiency in the synthesis of the desired compounds and can be easily recovered by centrifuge and reused at least five times without a decrease in catalytic activity.

Conclusion: In this report, a novel bi metal-organic framework (Ce0.47/Ni0.53–BTC) is synthesized via the cathodic electrosynthesis method. The synthesized b–MOF is fully characterized by several characterization methods. The catalytic activity of Ce0.47/Ni0.53–BTC is investigated in the synthesis of chromeno[4, 3–b]quinolone derivatives via one-pot four-component reaction of dimedone, aromatic aldehyde, 4–hydroxycoumarin and ammonium acetate. The reaction optimization results showed that the highest isolated yield was obtained when the reaction was performed in solvent-free conditions at 110 °C. The catalyst showed to be highly efficient in the synthesis of the desired compounds and performing the reaction utilizing various starting materials gave the products in good isolated yields, which proves the generality and the scope of the method. The catalyst could easily be recovered by centrifuge and reused at least five times without a decrease in catalytic activity.

目的：合成新型双金属有机骨架（b-MOF）并用作多相催化剂，用于通过二甲酮的一锅法和无溶剂四组分反应合成色诺[4, 3-b]喹诺酮衍生物，芳香醛、4-羟基香豆素和醋酸铵，110°C。

背景：b-MOFs 可在许多有机化合物的合成中用作多相催化剂。b-MOFs 中的活性和多用途位点在其催化应用中提供了多种功能。本文采用还原CES法合成Ce _0.47 /Ni _0.53 –BTC b–MOF。所得的 b-MOF 用作非均相催化剂，通过二甲酮、芳香醛、4-羟基香豆素和醋酸铵在 110°下的一锅无溶剂四组分反应合成色基 [4, 3-b] 喹诺酮C。

方法：在电化学电池中合成Ce _0.47 /Ni _0.53 –BTC，电化学电池由 5cm×5cm 的不锈钢箔组成，以两块 5cm×5cm 尺寸的石墨板为阳极，阴极电流密度为 0.2 A/dm ²并置于硝酸铈（0.3克）、硝酸镍（0.3克）、H ₃ BTC（0.2克）和NaNO ₃（0.1克）在乙醇（500毫升）中的溶液中。Ce _0.47 /Ni _0.53将 –BTC (10 mg) 加入二甲酮 (1 mmol)、芳香醛 (1 mmol)、羟基香豆素 (1 mmol) 和醋酸铵 (1.5 mmol) 的混合物中，并在 110 °C 无溶剂条件下搅拌 45分钟 通过TLC（己烷：乙酸乙酯，4：1）控制反应的发生。然后，将沸腾的乙醇加入到反应混合物中并在室温下搅拌15分钟。反应完成后，通过离心分离催化剂。最后，将反应混合物置于冰浴中，得到白色固体产物并从乙醇中重结晶得到纯产物。

结果：b-MOF 催化剂在合成所需化合物方面表现出非常好的效率，并且可以通过离心机轻松回收并重复使用至少 5 次，而催化活性不会降低。

结论：在本报告中，通过阴极电合成方法合成了一种新型双金属有机骨架（Ce0.47/Ni0.53-BTC）。合成的 b-MOF 可通过多种表征方法进行充分表征。通过二甲酮、芳香醛、4-羟基香豆素和乙酸铵的一锅四组分反应，研究了 Ce0.47/Ni0.53-BTC 在合成色诺 [4, 3-b] 喹诺酮衍生物中的催化活性。反应优化结果表明，当反应在无溶剂条件下于 110 °C 进行时，获得了最高的分离收率。该催化剂在所需化合物的合成中表现出很高的效率，并且利用各种原料进行反应，得到的产物分离收率良好，证明了该方法的通用性和适用范围。