7498-85-3Relevant academic research and scientific papers
Hybrid mesoporous organosilicas with molecularly imprinted cavities: Towards extended exposure of active amino groups in the framework wall
Huo, Hang,Xu, Xianzhu,Zhao, Tingting,Li, Yudong,Jiang, Yanqiu,Lin, Kaifeng
, p. 4508 - 4517 (2018)
Hybrid molecularly imprinted mesoporous silicas were synthesized by co-condensation of tetraethoxysilane and functional organosilica precursors of HQP and BPAP, in which hydroquinone (HQ) and bisphenol A (BPA) were linked as imprinting molecules. Owing to
One-Pot Synthesis of Zeolitic Strong Solid Bases: A Family of Alkaline-Earth Metal-Containing Silicalite-1
Zhou, Yu,Jin, Yanhua,Wang, Meng,Zhang, Wei,Xie, Jingyan,Gu, Jing,Wen, Haimeng,Wang, Jun,Peng, Luming
, p. 15412 - 15420 (2015)
Fabricating stable strong basic sites in well-preserved crystallized zeolitic frameworks still remains a difficult issue. Here, we reported a family of MFI-type metallosilicate zeolites, AeS-1 (Ae: alkaline-earth metal ions of Mg, Ca, Sr or Ba; S-1: silic
Mg2+-derived mesoporous ultra-high silica twelve-membered-ring basic zeolites: Straightforward synthesis and catalytic performance
Xie, Jingyan,Wen, Haimeng,Zhang, Wei,Zhou, Yu,Wang, Jun
, p. 1164 - 1173 (2016)
Mg2+-derived mesoporous ultra-high silica twelve-membered-ring zeolites with multiple topologies (MOR, BEA and MTW) were straightforwardly synthesized by a one-pot route, where the crucial step was the co-hydrolysis/condensation of silica source and magnesium salt under moderate acidic conditions. SiO2/Al2O3 ratios can be adjusted from ～30 to as high as 410, thus generating superior basicity that was further improved by the incorporation of Mg species. A mesoporous structure was self-formed without the assistance of any template or special strategy. Catalysis tests showed high activity of these zeolites in a typical base reaction, Knoevenagel condensation, even for the bulky substrates due to the enhanced mass transfer arising from the mesopores. This methodology provides a promising approach towards target synthesis of valuable Mg2+-derived mesoporous ultra-high silica zeolites with tunable acid/base properties, which can even act as an efficient mesoporous zeolitic solid base.
MOFs assembled from C 3symmetric ligands: Structure, iodine capture and role as bifunctional catalysts towards the oxidation-Knoevenagel cascade reaction
Zhang, Ying-Ying,Liu, Qing,Zhang, Lin-Yan,Bao, Yu-Mei,Tan, Jing-Yi,Zhang, Na,Zhang, Jian-Yong,Liu, Zhen-Jiang
supporting information, p. 647 - 659 (2021/01/28)
Three new NiII/CoII-metal organic frameworks were self-assembled by the reaction of C3 symmetric 1,3,5-tribenzoic acid (H3BTC) and 2,4,6-tris(4-pyridyl)-1,3,5-triazine (4-TPT) ligands and NiII/CoII salts under solvothermal conditions. Isomorphous MOF1 and MOF2 exhibit a 3D pillar-layer framework based on binuclear M2(OH)(COO)2 units connected by tritopic BTC3- and 4-TPT ligands with a novel (3,5)-connected topology net. MOF3 displays a 3-fold interpenetrated 3D network exhibiting a (3,4)-connected topology net. The porous MOF3 can reversibly take up I2. The activated MOFs contain both Lewis acid (NiII center) and basic (uncoordinated pyridyl or carboxylic groups) sites, and act as bifunctional acid-base catalysts. The catalytic measurements demonstrate that the activated MOF3 exhibits good activities for benzyl alcohol oxidation and the Knoevenagel reaction and can be recycled and reused for at least four cycles without losing its structural integrity and high catalytic activity. Thus, the catalytic properties for the oxidation-Knoevenagel cascade reaction have also been studied.
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.
Synthesis of multifunctional polymer containing Ni-Pd NPs via thiol-ene reaction for one-pot cascade reactions
Javad Kalbasi, Roozbeh,Mesgarsaravi, Niloofar,Gharibi, Reza
, (2019/02/03)
Recently, acid–base bifunctional catalysts have been considered due to their abilities, such as the simultaneous activation of electrophilic and nucleophilic species and their high importance in organic syntheses. However, the synthesis of acid–base catalysts is problematic due to the neutralization of acidic and basic groups. This work reports a facial approach to solve this problem via the synthesis of a novel bifunctional polymer using inexpensive materials and easy methods. In this way, at the first step, heterogeneous poly (styrene sulfonic acid-n-vinylimidazole) containing pentaerythritol tetra-(3-mercaptopropionate) (PETMP) and trimethylolpropane trimethacrylate (TMPTMA) cross-linkers were synthesized in the pores of a mesoporous silica structure using click reaction as a novel bifunctional acid–base catalyst. After that, Ni-Pd nanoparticles supported on poly (styrenesulfonic acid-n-vinylimidazole)/KIT-6 as a novel trifunctional heterogeneous acid–base-metal catalyst was prepared. The prepared catalysts were characterized by various techniques like FT-IR, TGA, ICP-AES, DRS-UV, TEM, FE-SEM, EDS-Mapping, and XRD. The synthesized catalysts were efficiently used as bifunctional/trifunctional catalysts for one-pot, deacetalization-Knoevenagel condensation and one-pot, three-step and a sequential reaction containing deacetalization-Knoevenagel condensation-reduction reaction. It is important to note that the synthesized catalyst showing high chemo-selectivity for the reduction of nitro group, alkenyl double bond and ester group in the presence of nitrile. Moreover, it was found that the different nanoparticles including Ni, Pd, and alloyed Ni-Pd showing different chemo-selectivity and catalytic activity in the reaction.
Direct fabrication of strong basic sites on ordered nanoporous materials: Exploring the possibility of metal-organic frameworks
Liu, Wei,Zhu, Li,Jiang, Yao,Liu, Xiao-Qin,Sun, Lin-Bing
, p. 1686 - 1694 (2018/03/21)
Heterogeneous strong base catalysts possessing ordered nanoporous structure are highly expected due to their high activity and shape selectivity in diverse reactions. However, their fabrication remains a great challenge because quite high temperatures (600-700 °C) are compulsory for the generation of strong basicity on conventional ordered nanoporous materials (i.e., zeolites and mesoporous silicas). Here, we report for the first time direct fabrication of strong basic sites on metal-organic frameworks (MOFs) by using guest-host redox (GHR) interaction between base precursors and low-valence metal centers (e.g., Cr3+), which breaks the tradition of thermo-induced decomposition of base precursors. It is fascinating that base precursor KNO3 can be converted to strong basic species on MIL-53(Cr) at 300 °C, which is much lower than that on zeolite Y (700 °C) and mesoporous silica SBA-15 (600 °C). The resultant solid base exhibits strong basicity, ordered nanoporous structure, and high activity and shape selectivity in base-catalyzed reactions.
Vanadium-Catalyzed Condensation of Ethyl Cyanoacetate with Ketones
Khusnutdinov,Shchadneva,Mayakova, Yu. Yu.
, p. 403 - 409 (2018/04/24)
Vanadium compounds and complexes activated by pyridine or morpholine catalyze condensation of ethyl cyanoacetate with ketones and aldehydes leading to alkylidenecyanoacetates in 75–100% yield.
Fe3O4@UiO-66-NH2 core–shell nanohybrid as stable heterogeneous catalyst for Knoevenagel condensation
Zhang, Yanmei,Dai, Tianlin,Zhang, Fan,Zhang, Jing,Chu, Gang,Quan, Chunshan
, p. 2106 - 2113 (2017/01/16)
Magnetic separation is an attractive alternative to filtration or centrifugation for separating solid catalysts from a liquid phase. Here, core-shell Fe3O4@UiO-66-NH2nanohybrids with well-defined structures were constructe
A carboxylate-rich metalloligand and its heterometallic coordination polymers: Syntheses, structures, topologies, and heterogeneous catalysis
Srivastava, Sumit,Kumar, Vijay,Gupta, Rajeev
, p. 2874 - 2886 (2016/06/01)
This work reports three heterometallic coordination polymers (HCPs), namely, [{(1′)2Zn8Na2(H2O)21}·20H2O]n (2), [{(1′)(1')Cd8(H2O)21}·32H2/
