96238-12-9Relevant articles and documents
Phosphorous acid functionalized polyacrylonitrile fibers with a polarity tunable surface micro-environment for one-pot C-C and C-N bond formation reactions
Xu, Gang,Wang, Lu,Li, Mengmeng,Tao, Minli,Zhang, Wenqin
, p. 5818 - 5830 (2017)
The preparation and application of fiber catalysts have attracted much attention. However, research on the effect of the micro-environment of fiber catalysts on the catalytic activities though of special importance is limited. In this work, a novel strategy for the synthesis of phosphoric acid-functionalized polyacrylonitrile fibers with a polarity tunable surface micro-environment by hydrophobic groups for one-pot C-C and C-N bond formation reactions is reported. The special hydrophobic surface micro-environment of the fiber catalysts is proven to promote the catalytic activities impressively in cyclocondensation of β-ketoesters with 2-aminobenzamides, the Knoevenagel condensation as well as the multi-component Biginelli reactions in green solvents. Both the surface synergy of the catalytic sites and hydrophobic auxiliary groups (benzyl or n-butyl) in the surface of fiber catalysts and interface acceleration in reaction medium play an important role in the highly efficient promotion of catalytic activity. Thereby a surface synergistic mechanism is proposed to explain the micro-environment effect. In addition, the fiber catalysts could be simply separated from the reaction system using tweezers and directly used in the next cycle without further treatment. Importantly, even after 10 reaction cycles in water or ethanol, there is no significant loss in their catalytic activity. The results indicate that the phosphoric acid functionalized fibers show green and sustainable potential for industrial production.
Highly Active Copper(I)-Chalcogenone Catalyzed Knoevenagel Condensation Reaction Using Various Aldehydes and Active Methylene Compounds
Mannarsamy, Maruthupandi,Prabusankar, Ganesan
, (2021/10/05)
First copper(I) chalcogenones catalysed Knoevenagel Condensation reactions have been reported. No illustration of the utilization of this copper-chalcogenone complex class in Knoevenagel Condensation catalysis can be found. Thus, copper(I) bis(benzimidazole-2-chalcogenone) catalysts [Cu(L1)4]+BF4? (1) and [Cu(L2)4]+BF4? (2) (L1 = bis(1-isopropyl-benzimidazole-2-selone)-3-ethyl; L2 = bis(1-isopropyl-benzimidazole-2-thione)-3-ethyl) have been utilized as catalysts in the Knoevenagel Condensation reactions. These copper(I) chalcogenone catalysts have shown high efficiency for the catalytic Knoevenagel Condensation of aryl aldehydes and active methylene compounds. In particular, complex 2, exhibit the best catalytic activities. The scope of the catalytic reactions has been investigated with 22 different molecules. The excellent catalytic activity has been depicted for various types of substrates with either electron-rich or deficient aryl aldehydes. The present investigation features relatively mild reaction conditions with good functional group tolerance and excellent yields. Graphic Abstract: The first copper(I)-chalcogenone complexes catalysed Knoevenagel Condensation reactions?have also been investigated, and revealed the best catalytic activities. [Figure not available: see fulltext.]
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
