• Journal of the Korean Chemical Society
• /
• v.52 no.5
• /
• pp.593-596
• /
• 2008

• Journal of the Korean Chemical Society
• /
• v.55 no.3
• /
• pp.430-435
• /
• 2011

Coal fly ash of thermal power plants converted into mesoporous materials MCM-41. The synthesized material was characterized by XRD, FT-IR, SEM, and EDS techniques. The catalytic activity of prepared material was studied for the synthesis of 5-arylindene malononitriles via Knoevenagel condensation of aromatic aldehydes and malonontrile is described. The features of present method are easy handling, stability, reusability, and eco-friendliness of catalyst, high yields, short reaction time, simple experimental and work up procedure.

• Journal of the Korean Chemical Society
• /
• v.49 no.4
• /
• pp.377-380
• /
• 2005

• Journal of the Korean Chemical Society
• /
• v.55 no.6
• /
• pp.1000-1006
• /
• 2011

A systematic study of Knoevenagel reaction and Nazarov cyclization was made on variety of less reactive carbonyl compounds such as ${\beta}$-ketoesters, 1,3-diketones and cyclic active methylene compounds using $Yb(OTf)_3$ as the catalyst. Recycling study confirms reusability of the catalyst without much loss of activity.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.5
• /
• pp.1301-1304
• /
• 2010

The Indium modified mesoporous zeolite AlMCM-41 were synthesized by hydrothermal method and characterized by powder X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) techniques. The Knoevenagel condensation of aldehyde with malononitrile or ethyl cyanoacetate was carried out at reflux condition in ethanol by using heterogeneous In/AlMCM-41 catalyst. This method is fast, efficient, easy work-up and eco-friendly to afford the corresponding Knoevenagel adducts. The catalyst was recovered and reused for several cycles with consistent activity.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.11
• /
• pp.2833-2836
• /
• 2009

• Journal of the Korean Chemical Society
• /
• v.51 no.4
• /
• pp.346-351
• /
• 2007

Efficient stereoselective synthesis of α,β-Unsaturated acids, α-Cyanoacrylonitriles and α-Cyanoacrylates has been carried out in the presence of NaHSO4·SiO2 under solvent?free conditions with an E-geometry.

• Korean Chemical Engineering Research
• /
• v.44 no.4
• /
• pp.417-423
• /
• 2006

A series of amine functionalized MCM-41 catalysts were prepared by aminopropyltrimethoxysilane grafting and their catalytic performance in Knoevenagel reaction of selected substrates was investigated. Water resistant and catalytically active amine grafted MCM-41 was prepared by post-synthetic silylation using methyltrimethoxysilane ; hydrogen bonding of the water molecules formed during the condensation reaction to the active N group was suppressed, which led to high TON of the reaction. Amine functionalized MCM-41 prepared by coating method produced high conversion, but the TON of the catalyst was much lower than that of the amine grafted MCM-41; pore volume of the functionalized MCM-41 decreased substantially and large portion of the immobilized amine is believed to be hydrogen bonded to each other, which can result in decrease in the basicity of the N group. A secondary amine group was prepared by room temperature condensation between aminopropylsilane and chloropropylsilane, and the MCM-41 grafted with the secondary amine group demonstrated the highest catalytic activity among the catalysts prepared.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.10
• /
• pp.2419-2421
• /
• 2009

A simple and efficient method has been developed for Knoevenagel condensation between aldehydes or ketones and active methylene group by stirring in methylene chloride at 60 ${^{\circ}C}$ under heterogeneous conditions using silica supported ammonium acetate. The products are obtained in excellent yields and are in a state of high purity. The structures of the products were confirmed by IR, $^1H$ NMR and mass spectral data and comparison with authentic samples available commercially.

• Journal of the Korean Chemical Society
• /
• v.7 no.1
• /
• pp.85-90
• /
• 1963

The Knoevenagel reaction of fluorinated carbonyl compounds, 1,1,1-trifluoro-propanone-2-heptafluoro-butyraldehyde, 1,3-dichloro-1,1,3,3-tetrafluoro-acetone, tetradecafluoro-heptanone-4 and 2,2,2-trifluoro-acetophenone yielded fluorinated ${\beta},{\beta}$-dialkyl-${\beta}$-hydroxy acids. Dehydration of the acids do not give the olefinic acid in the case of the perfluorinated system and gave a lactone. From the consideration of electronic and steric effects a mechanismic path of the reaction via a carbanion intermediate was proposed for the reaction. Preparation of related derivatives are also described.