2972-83-0Relevant articles and documents
Hierarchical Micro- and Mesoporous Zn-Based Metal–Organic Frameworks Templated by Hydrogels: Their Use for Enzyme Immobilization and Catalysis of Knoevenagel Reaction
Cheng, Kaipeng,Svec, Frantisek,Lv, Yongqin,Tan, Tianwei
, (2019)
Encapsulation of enzymes in metal–organic frameworks (MOFs) is often obstructed by the small size of the orifices typical of most reported MOFs, which prevent the passage of larger-size enzymes. Here, the preparation of hierarchical micro- and mesoporous
A green synthesis of a simple chemosensor that could instantly detect cyanide with high selectivity in aqueous solution
Lin, Qi,Chen, Pei,Fu, Yong-Peng,Zhang, You-Ming,Shi, Bing-Bing,Zhang, Peng,Wei, Tai-Bao
, p. 699 - 702 (2013)
A novel and simple cyanide chemosensor 2-(naphthalen-1-ylmethylene) malononitrile (L) was designed and synthesized via a green chemistry method in water without using any catalyst. The chemosensor showed an excellent sensitivity and selectivity for CN- in aqueous solution. The detection limit could be as low as 1.6 × 10-7 mol/L (0.16 μmol/L), which is far lower than the WHO guideline of 1.9 μmol/L cyanide for drink water.
Halloysite nanotubes (HNTs)@ZIF-67 composites - A new type of heterogeneous catalyst for the Knoevenagel condensation reaction
Hou, Buwei,Wu, Jie
, p. 17621 - 17628 (2020)
Composite materials based on metal-organic frameworks (MOFs) have shown outstanding performance due to their high porosity, molecular-level characterization, and structural and functional tunability. In this article, we develop a new type of composite material - HNTs@ZIF-67 - by the in situ growth of ZIF-67 nanoparticles (NPs) on halloysite nanotubes (HNTs), which were characterized by SEM, TEM, PXRD, FT-IR, TGA, XPS and N2 adsorption-desorption isotherms. The results clearly indicate that HNTs were wrapped in the ZIF-67 shell with a thickness of 50 nm which is much smaller than the 500 nm size of the as-synthesized ZIF-67. The nano-sized HNTs@ZIF-67 can effectively catalyze the Knoevenagel condensation reaction of larger conjugated/heterocyclic aromatic formaldehydes with malononitrile. The catalytic activities with >99% yields for the reaction of 4-pyridinecarboxaldehyde with malononitrile were maintained even after three cycles, and the composite still retained the original structure and morphology. This journal is
Impact of an aryl bulky group on a one-pot reaction of aldehyde with malononitrile and: N-substituted 2-cyanoacetamide
Vala, Ruturajsinh M.,Patel, Divyang M.,Sharma, Mayank G.,Patel, Hitendra M.
, p. 28886 - 28893 (2019)
In this study, we successfully explored the effect of steric hindrance on the one-pot reaction of different aryl aldehydes with malononitrile and N-substituted 2-cyanoacetamide in the presence of piperidinium acetate as the catalyst. It involved the Knoevenagel condensation of the aldehyde and malononitrile to produce arylidene malononitrile as an intermediate, which was further treated with N-substituted 2-cyanoacetamide to give 6-Amino-2-pyridone-3,5-dicarbonitrile derivatives when the less steric bulky group was involved. High steric hindrance changed the earlier reaction route and gave N-substituted 2-cyanoacrylamides via a slower route.
Function-Structure Relationship in Metal-Organic Frameworks for Mild, Green, and Fast Catalytic C-C Bond Formation
Razavi, Sayed Ali Akbar,Morsali, Ali
, p. 14429 - 14439 (2019)
Tunability in chemical functionality is a promising characteristic of metal-organic frameworks (MOFs), which plays an important role in developing and improving the practical applications of MOFs. Here, we applied this important feature of MOFs to be in line with sustainable development and green chemistry principles through the synthesis of MOF-based heterogeneous organocatalysts. According to our green functionalization strategy, some isostructural MOFs (azine decorated TMU-4 with the formula [Zn(OBA)(BPDB)0.5]n·2DMF, azine-methyl functionalized TMU-5 with the formula [Zn(OBA)(BPDH)0.5]n·1.5DMF, dihydro-tetrazine decorated TMU-34 with the formula [Zn(OBA)(H2DPT)0.5]n·DMF, and tetrazine functionalized TMU-34(-2H) with the formula [Zn(OBA)(DPT)0.5]n·DMF, where H2OBA = 4,4′-oxybis(benzoic acid), BPDB = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene, BPDH = 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene, H2DPT = 3,6-di(pyridin-4-yl)-1,4-dihydro-1,2,4,5-tetrazine, and DPT = 3,6-di(pyridin-4-yl)-1,2,4,5-tetrazine) have been applied for mild, green, and fast Knoevenagel condensation. These frameworks display different Lewis basic catalytic activities owing to their different functionality and function accessibility. Contrary to extensive articles published about Knoevenagel condensation, this study involves the rare examples in Knoevenagel condensation with such mild conditions (room temperature and atmospheric pressure) and with a green solution (water as the solvent). Due to the combined synergic effects of the Lewis basicity of TMU-frameworks, the amphoteric and hydrogen bond-participating nature of water molecules, maximum conversion times are reached just after 30 min (for TMU-5) and 60 min (for TMU-34). Stability and recyclability tests show that TMU-5 and TMU-34 are completely stable in water at reaction conditions and can retain their crystallinity, porosity, and functionality even after five cycles without any specific reduction in their catalytic conversion. Since, in many cases, amine decorated MOFs are applied in Knoevenagel catalyzed condensation, this study is beneficial in providing information about the effects of azine and tetrazine functional groups in reactant activation and the acceleration of Knoevenagel condensation.
A readily accessible porous organic polymer facilitates high-yielding Knoevenagel condensation at room temperature both in water and under solvent-free mechanochemical conditions
Sarma, Parishmita,Sarmah, Kashyap Kumar,Kakoti, Dharittri,Mahanta, Sanjeev Pran,Adassooriya, Nadeesh Madusanka,Nandi, Goutam,Das, Pranab Jyoti,Bu?ar, Dejan-Kre?imir,Thakuria, Ranjit
, (2021/03/24)
A novel nitrogen-rich amorphous porous organic polymer has been synthesized using a microwave-assisted process. Its high chemical stability, reusability and poor solubility enable the use of the porous polymer as a metal-free heterogeneous catalyst for C–
Kinetically Controllable Pd-Catalyzed Decarboxylation Enabled [5 + 2] and [3 + 2] Cycloaddition toward Carbocycles Featuring Quaternary Carbons
Yan, Biwei,Zuo, Linhong,Chang, Xiaowei,Liu, Teng,Cui, Manying,Liu, Yang,Sun, Haiyu,Chen, Weipeng,Guo, Wusheng
supporting information, p. 351 - 357 (2021/01/26)
A decarboxylative protocol has been developed toward a range of carbocycles. The key success is based on the use of a batch of newly designed cyclic carbonates as substrates that can provide carbon-carbon zwitterion intermediate under palladium catalysis.
