23973-22-0Relevant academic research and scientific papers
Amine-bridged periodic mesoporous organosilica nanospheres as an active and reusable solid base-catalyst for water-medium and solvent-free organic reactions
Zhu, Fengxia,Yang, Didi,Zhang, Fang,Li, Hexing
, p. 387 - 397,11 (2012)
An amine-bridged periodic mesoporous organosilica catalyst in uniform nanospheres (~85 nm) (NH-PMO-NS) was synthesized by surfactant-directed co-condensation between amine-bridged silane and tetraethoxysilane (TEOS). As-prepared NH-PMO-NS contained short and straight mesoporous channels with amine-groups integrally incorporated into silica walls. In water-medium Knoevenagel condensation and solvent-free Henry reactions, this catalyst exhibited much higher activity and selectivity than both the common amine-bridged PMO (NH-PMO-com) with irregular shape synthesized by traditional method and the amine-functionalized MCM-41 in nanospheres (NH-MCM-NS) prepared by grafting amine-groups onto the pore surface. In addition, it displayed comparable catalytic efficiencies with the homogeneous base-catalyst (diethylamine), and could also be easily recovered and used repetitively. Based on the structural characterizations and kinetic studies, the high catalytic activity and selectivity were ascribed to the short and straight mesoporous channels in nanospheres with amine-groups incorporated into silica walls. The accessible basic catalytic sites may facilitate the diffusion and thus, promoted the adsorption of organic reactant molecules, leading to the enhanced activity and selectivity.
Microporous carbon nitride as an effective solid base catalyst for Knoevenagel condensation reactions
Xu, Jie,Shen, Kang,Xue, Bing,Li, Yong-Xin
, p. 105 - 113 (2013)
Microporous graphitic carbon nitride (CN-Mic) material has been prepared using carbon tetrachloride and ethylene diamine as precursors, and a siliceous microporous MCM-22 as a hard template. A series of Knoevenagel condensation reactions have been performed over the CN-Mic sample, and the influences of reaction conditions on the corresponding catalytic behavior have been investigated. The results showed that the CN-Mic material exhibited high catalytic activity and versatility for the condensation reactions. XPS and FT-IR analysis reveal a high abundance of the N-containing groups located on the surface of CN-Mic, which accounts for the superior catalytic activity of the carbon nitride material as a promising new type of heterogeneous Lewis base catalyst for the condensation reactions. It is also revealed that the activity of CN-Mic is much higher than those obtained over mesoporous g-CN materials. Meanwhile, the catalytic results of CN-Mic compared favorably with those of other g-CN materials for Knoevenagel reactions reported previously. In addition, a mechanism for the CN-Mic catalyzed Knoevenagel condensation was tentatively proposed.
Sodium benzoate as a green, efficient, and recyclable catalyst for knoevenagel condensation
Liu, Qing,Ai, Hong-Mei
, p. 3004 - 3010 (2012)
Sodium benzoate was utilized as a novel efficient and green catalyst for the Knoevenagel condensation of aldehydes with active methylene compounds such as ethyl cyanoacetate and malononitrile to afford substituted olefins through the conventional stirring
Nitrogen-doped carbon nanotubes with variable basicity: Preparation and catalytic properties
Wang, Lingling,Wang, Lijun,Jin, Haiying,Bing, Naici
, p. 78 - 81 (2011)
Nitrogen-doped carbon nanotubes with variable basicity have been synthesized by CVD method using Fe-SBA-15 as catalysts. The precursors had notable influence on the basicity of CNx. The highest amount of pyridinic-like nitrogen atom contributed to the bas
Highly active zinc oxide-supported lithium oxide catalyst for solvent-free Knoevenagel condensation
Basude, Manohar,Bhongiri, Yadagiri,Masula, Keshavulu,Pasala, Vijay Kumar,Puppala, Veerasomaiah,Sunkara, Prasad
, (2021/07/09)
Li2O/ZnO catalyst was prepared by wet impregnation method and characterized by XRD, SEM, EDX, FTIR, BET surface area and UV-Vis diffuse reflectance spectroscopy. This study revealed a decrease in average particle size and change in the shape of
Ammonium chloride catalyzed Knoevenagel condensation in PEG-400 as ecofriendly solvent
Waghmare, Smita R.
, p. 849 - 855 (2021/09/28)
A simple and selective green methodology has been successfully developed for Knoevenagel condensation in polyethylene glycol-400 using 10 mol % ammonium chloride as catalyst. The method is applicable to a wide range of aromatic, heteroaromatic and α,β-unsaturated aldehydes. The reactions have been found to be clean and free from the formation of the Michael adduct.
Ammonium chloride: An efficient and environmentally benign catalyst for knoevenagel condensation of carbonyl and active methylene compounds
Tasqeeruddin,Asiri, Yahya I.,Mujahid Alam
, p. 3024 - 3028 (2021/01/06)
In the present study, a rapid, simple and an efficient procedure for the Knoevenagel condensation of various carbonyl and active methylene compounds in ethanol at a moderate temperature in the presence of a catalytic amount of an efficient, environmentall
Silica bonded N-(propylcarbamoyl)sulfamic acid (SBPCSA) as a highly efficient and recyclable solid catalyst for the synthesis of Benzylidene Acrylate derivatives: Docking and reverse docking integrated approach of network pharmacology
Aslam, Afroz,Parveen, Mehtab,Alam, Mahboob,Silva, Manuela Ramos,Silva, P.S. Pereira
, (2020/08/17)
A green approach has been developed for the synthesis of a series of benzylidene acrylate 3(a-p) from differently substituted aromatic/heterocyclic aldehydes and ethyl cyanoacetate in excellent yields (90–98%), and employing silica bonded N-(Propylcarbamoyl)sulfamic acid as a recyclable catalyst under solvent-free condition. The molecular structure of compounds 3b, 3d and 3i were well supported by single-crystal X-ray crystallographic analysis. The present protocol bears wide substrate tolerance and is believed to be more practical, efficient, eco-friendly, and compatible as compared to existing methods. In-silico approaches were implemented to find the biochemical and physiological effects, toxicity, and biological profiles of the synthesized compounds to determine the expected biological nature and confirm a drug-like compound. A molecular docking study of the expected biologically active compound was performed to know the hypothetically binding mode with the receptor. Also, reverse docking is applied to recognize receptors from unknown protein targets for drug-like compounds to explain poly-pharmacology and binding postures with different receptors.
Johnson-Corey-Chaykovsky fluorocyclopropanation of double activated alkenes: Scope and limitations
Kazia, Armands,Melngaile, Renate,Mishnev, Anatoly,Veliks, Janis
supporting information, p. 1384 - 1388 (2020/03/03)
Johnson-Corey-Chaykovsky fluorocyclopropanation of double activated alkenes utilizing S-monofluoromethyl-S-phenyl-2,3,4,5-tetramethylphenylsulfonium tetrafluoroborate is an efficient approach to obtain a range of monofluorocyclopropane derivatives. So far, fluoromethylsulfonium salts have displayed the broadest scope for direct fluoromethylene transfer. In contrast to more commonly used fluorohalomethanes or freon derivatives, diarylfluoromethylsulfonium salts are bench stable, easy-to use reagents useful for the direct transfer of a fluoromethylene group to alkenes giving access to the challenging products-fluorocyclopropane derivatives. Interplay between the reactivity of the starting materials and stability of the fluorocyclopropanes formed determines the outcome of the process.
Prolinamide functionalized polyacrylonitrile fiber with tunable linker length and surface microenvironment as efficient catalyst for Knoevenagel condensation and related multicomponent tandem reactions
Zhu, Hai,Xu, Gang,Du, Huimin,Zhang, Chenlu,Ma, Ning,Zhang, Wenqin
, p. 217 - 229 (2019/05/16)
A series of new prolinamide polyacrylonitrile fiber catalysts with tunable length of alkyl linker and different linker group were prepared by covalent bonding for the first time and well characterized by mechanical strength, FT-IR, XRD, EA, TGA, SEM and water contact angel. The catalytic activities of these fiber catalysts were evaluated in Knoevenagel condensation and one-pot Knoevenagel-Michael multicomponent tandem reactions to synthesize α, β-unsaturated nitrile and 2-amino-4H-chromene derivatives in water. The result show that the suitable linker length attaching amines to fiber matrix as well as the constructed hydrophobic microenvironment by linker group within the surface layers of fiber materials effectively promotes the reactions. In addition, the good swollen capacity of fiber in solvent ensure that the reaction proceed well. Fiber catalyst PANPA?2F modified by prolinamide with a C2 alkyl chain exhibited the best catalytic performance and can be easily recovered and reused for at least ten consecutive cycles without significant loss of catalytic activity and active sites leaching.
