Ghobakhloo Farzaneh, Azarifar Davood, Mohammadi Masoud, Keypour Hassan, Zeynali Hamid
Department of Organic Chemistry, Bu-Ali Sina University, Hamedan 6517838683, Iran.
Department of Chemistry, Faculty of Science, Ilam University, P.O. Box 69315516, Ilam 6931173385, Iran.
Inorg Chem. 2022 Mar 28;61(12):4825-4841. doi: 10.1021/acs.inorgchem.1c03284. Epub 2022 Mar 14.
The synthesis of five- and six-membered oxygen- and nitrogen-containing heterocycles has been regarded as the most fundamental issue in organic chemistry and chemical industry because they are used in producing high-value products. In this study, an efficient, economic, sustainable, and green protocol for multicomponent synthesis has been developed. The one-pot direct Knoevenagel condensation-Michael addition-cyclization sequences for the transformation of aromatic aldehydes, malononitrile, and 4-hydroxycoumarin or phthalhydrazide generate the corresponding dihydropyrano[2,3-]chromenes and 1-pyrazolo[1,2-]phthalazine-5,10-diones over a novel mesoporous metal-organic framework-based supported Cu(II) nanocatalyst [UiO-66@Schiff-Base-Cu(II)] under ambient conditions. Moreover, the [UiO-66@Schiff-Base-Cu(II)] complex efficiently catalyzed the selectively large-scale synthesis of the target molecules with high yield and large turnover numbers. As presented, the catalyst demonstrates excellent reusability and stability and can be recycled up to six runs without noticeable loss of activity. Moreover, ICP-AES analysis showed that no leaching of Cu complex occurred during the recycling process of the heterogeneous [UiO-66@Schiff-Base-Cu(II)] nanocatalyst.
五元及六元含氧和含氮杂环的合成一直被视为有机化学和化学工业中最基本的问题,因为它们用于生产高价值产品。在本研究中,已开发出一种高效、经济、可持续且绿色的多组分合成方法。在新型介孔金属有机骨架负载的铜(II)纳米催化剂[UiO - 66@席夫碱 - Cu(II)]作用下,在环境条件下,芳醛、丙二腈与4 - 羟基香豆素或邻苯二甲酰肼通过一锅法直接进行Knoevenagel缩合 - 迈克尔加成 - 环化反应,生成相应的二氢吡喃并[2,3 - ]色烯和1 - 吡唑并[1,2 - ]酞嗪 - 5,10 - 二酮。此外,[UiO - 66@席夫碱 - Cu(II)]配合物能高效催化目标分子的选择性大规模合成,产率高且周转数大。结果表明,该催化剂具有出色的可重复使用性和稳定性,可循环使用多达六次而活性无明显损失。此外,ICP - AES分析表明,在非均相[UiO - 66@席夫碱 - Cu(II)]纳米催化剂的循环过程中,未发生铜配合物的浸出。