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。
A one-pot, three-component synthesis of new pyrano[2,3-h]coumarin derivatives
The reaction between 5,7-dihydroxy-4-substituted coumarin, malononitrile, and aromatic aldehydes in the presence of a catalytic amount of K2CO3 as a basic catalyst leads to new pyrano[2,3-h]coumarin derivatives in good to excellent yields. (C) 2012 Elsevier Ltd. All rights reserved.