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Sodium Tungstate Supported on a Three‐dimensional and Networked SBA‐15 for Knoevenagel Reaction
Author(s) -
Yang Hongyuan,
Zhang Wei,
Liu Qing
Publication year - 2019
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201902653
Subject(s) - malononitrile , knoevenagel condensation , catalysis , sodium tungstate , nuclear chemistry , scanning electron microscope , desorption , inductively coupled plasma , fourier transform infrared spectroscopy , materials science , tungstate , chemistry , adsorption , inorganic chemistry , organic chemistry , chemical engineering , plasma , physics , quantum mechanics , engineering , tungsten , composite material
Sodium tungstate (ST) supported on a three‐dimensional and networked SBA‐15 ( 3D ‐SBA‐15) was utilized as a novel efficient catalyst for the Knoevenagel condensation of aldehydes with active methylene compounds such as malononitrile and ethyl cyanoacetate to afford substituted olefins through the conventional magnetic stirring or under ultrasound irradiation. ST/ 3D ‐SBA‐15 catalyst was prepared using an incipient wetness impregnation method and confirmed by series of characterizations such as Fourier‐transform infrared spectra (FT‐IR), scanning electron microscope (SEM), X‐ray diffraction (XRD), N 2 adsorption‐desorption and inductively coupled plasma‐optical emission spectroscopy. The reaction proceeded smoothly under the both stirring and ultrasound‐assisted conditions at room temperature. The 30ST/ 3D ‐SBA‐15 catalyst with 30 wt% loading of Na 2 WO 4 showed the highest catalytic performance with excellent yield within short time, and improvements were observed by carrying out the reactions under ultrasound irradiation. In addition, the solvent effect was significant in this work, and the optimum solvent was ethanol and water with volume ratio of 1 : 1.