Nano-Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>-supported boron sulfonic acid as a novel magnetically heterogeneous catalyst for the synthesis of pyrano coumarins
magnetically heterogeneouscatalyst based on the immobilization of boron sulfonicacid onto Fe3O4@SiO2 nanoparticles (Fe3O4@SiO2–BSA) is reported. Fe3O4@SiO2–BSA was characterized via FT-IR, X-ray diffraction patterns (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and vibrating sample magnetometer (VSM) analysis. The performance ability of this catalyst including
在这项研究中,报道了一种基于硼磺酸固定在Fe 3 O 4 @SiO 2纳米颗粒(Fe 3 O 4 @SiO 2 -BSA)上的新型磁性非均相催化剂。Fe 3 O 4 @SiO 2 –BSA通过FT-IR,X射线衍射图(XRD),扫描电子显微镜(SEM),能量色散X射线光谱(EDS)和振动样品磁力计(VSM)分析。在无溶剂条件下以高收率评估了该催化剂包括酸位点的性能,以合成吡喃香豆素。催化剂的热稳定性及其易于被磁场分离,使该催化剂成为良好的多相体系,并且是其他多相催化剂的有用替代品。
Sodium Tungstate: The First Application as Non-oxidative Catalyst in Organic Synthesis
作者:Saeed Khodabakhshi、Mojtaba Baghernejad
DOI:10.1002/jccs.201300529
日期:2014.5
A convenient synthesis of some pyranocoumarins was described via a one‐pot, three‐component reaction of 4‐hydroxyxoumarin, malononitrile and different aromatic aldehydes in the presence of sodium tungstate. This is the first application of sodium tungstate as non‐oxidative catalyst in organic reactions. Simple operation, use of readily available starting materials, good to excellent yields and short
Résumé Titanium dioxide nanowires were employed as novel, recyclable and safe catalysts in a one-pot three-component condensation of aldehydes, malononitrile, and 4-hydroxycoumarin to produce new and known pyrano[2,3-c]chromenes as potent biologically active compounds. A possible catalytic mechanism was also proposed based on the interaction of reactants with TiO2 nanowires. This expedient new route has advantages, such as the use of a safe and reusable catalyst, simple operation, short reaction times and good to excellent yields. Supplementary Materials: Supplementary material for this article is supplied as a separate file: mmc1.pdf
A new application of Mohr'ssalt (ammonium iron (II) sulfate hexahydrate) has been found in an organic reaction in which the Knoevenagel condensation, Michael addition, and intermolecular cyclization of 4-hydroxyxoumarin, malononitrile and aromatic aldehydes led to novel and known pyranocoumarins. Simple operation, use of readily accessible commercial starting materials, good to excellent yields and