Department of Chemistry, Payame Noor University (PNU), P.O. Box 19395-3697, Tehran, Iran.
Department of Chemistry, Faculty of Sciences, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Curr Org Synth. 2021;18(5):475-482. doi: 10.2174/1570179418666210122100240.
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.
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/Ni-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.
Ce/Ni-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/dm and placed in a solution of cerium nitrate (0.3 g), nickel nitrate (0.3 g), HBTC (0.2 g) and NaNO (0.1 g) in ethanol (500 mL). Ce/Ni-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.
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.
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.
合成新型双金属有机骨架（b-MOF）并将其用作多相催化剂，通过一锅法和无溶剂四组分反应，由二酮、芳香醛、4-羟基香豆素和乙酸铵在 110°C 下合成色烯并[4,3-b]喹啉衍生物。
b-MOF 可用作许多有机化合物合成的多相催化剂。b-MOF 中的活性和多功能位点在其催化应用中提供了不同的功能。在本文中，应用还原 CES 法合成 Ce/Ni-BTC b-MOF。所得 b-MOF 用作多相催化剂，通过一锅法和无溶剂四组分反应，由二酮、芳香醛、4-羟基香豆素和乙酸铵在 110°C 下合成色烯并[4,3-b]喹啉。
Ce/Ni-BTC 在由不锈钢箔（5cm×5cm，中心位于两个 5cm×5cm 大小的石墨板之间）作为阳极，通过 0.2 A/dm 的阴极电流密度在电化学电池中合成，放置在乙醇（500mL）中的硝酸铈（0.3g）、硝酸镍（0.3g）、HBTC（0.2g）和 NaNO（0.1g）溶液中。将 10mg 的 Ce/Ni-BTC 加入到二酮（1mmol）、芳香醛（1mmol）、羟基香豆素（1mmol）和乙酸铵（1.5mmol）的混合物中，并在无溶剂条件下于 110°C 下搅拌 45 分钟。通过 TLC（正己烷：乙酸乙酯，4:1）控制反应的演化。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。
b-MOF 催化剂在所需化合物的合成中表现出非常高的效率，并且可以通过离心轻松回收，至少可重复使用五次而不降低催化活性。
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）。通过几种特征化方法对合成的 b-MOF 进行了充分的表征。研究了 Ce0.47/Ni0.53-BTC 在一锅法和四组分反应中二酮、芳香醛、4-羟基香豆素和乙酸铵合成色烯并[4,3-b]喹啉衍生物中的催化活性。反应优化结果表明，在无溶剂条件下于 110°C 进行反应时，获得了最高的分离产率。催化剂在所需化合物的合成中表现出很高的效率，利用各种起始原料进行反应可获得良好的分离产率，证明了该方法的通用性和适用范围。催化剂可通过离心轻松回收，至少可重复使用五次而不降低催化活性。
