5553-92-4Relevant academic research and scientific papers
Direct Cyclopropanation of α-Cyano β-Aryl Alkanes by Light-Mediated Single Electron Transfer Between Donor–Acceptor Pairs
Li, Jing,Lear, Martin J.,Hayashi, Yujiro
supporting information, p. 5901 - 5905 (2021/03/09)
Cyclopropanes are traditionally prepared by the formal [2+1] addition of carbene or radical based C1 units to alkenes. In contrast, the one-pot intermolecular cyclopropanation of alkanes by redox active C1 units has remained unrealised. Herein, we achieve
Catalyst-Free [3 + 3] Annulation/Oxidation of Cyclic Amidines with Activated Olefins: When the Substrate Olefin Is Also an Oxidant
Han, Wendan,Li, Yuanhang,Raveendra Babu, Kaki,Li, Jing,Tang, Yuhai,Wu, Yong,Xu, Silong
, p. 7832 - 7841 (2021/06/25)
Herein we describe a catalyst-free regioselective [3 + 3] annulation/oxidation reaction of cyclic amidines such as DBU (1,8-diazabicyclo(5.4.0)undec-7-ene) and DBN (1,5-diazabicyclo(4.3.0)non-5-ene) with activated olefins, i.e., 2-arylidenemalononitriles and 2-cyano-3-aryl acrylates, to afford tricyclic 2-pyridones and pyridin-2(1H)-imines, respectively. The mechanism has been proposed based on DFT calculations. In the reaction, the cyclic amidines serve as C,N-bisnucleophiles for the cyclization, while the olefins play a dual role by acting as both reactants and oxidants.
Tandem Condensation-Hydrogenation to Produce Alkylated Nitriles Using Bifunctional Catalysts: Platinum Nanoparticles Supported on MOF-Derived Carbon
Huang, Ao,Nie, Renfeng,Zhang, Biying,Pei, Yuchen,Chen, Minda,Behera, Ranjan,Yu, Jiaqi,Luan, Xuechen,Hunter, Nicholas T.,Ke, Ming,Huang, Wenyu
, p. 602 - 608 (2019/12/27)
Tandem catalysis, which allows multiple steps of a reaction to take place without the need for separation and purification, is highly desired for the design of efficient and environmentally-friendly chemical processes. Herein, the pyrolysis of UiO-66-NHs
Mechanistic Investigations of Reactions of the Frustrated Lewis Pairs (Triarylphosphines/B(C6F5)3) with Michael Acceptors
Dupré, Jonathan,Gaumont, Annie-Claude,Lakhdar, Sami
supporting information, p. 694 - 697 (2017/02/10)
Frustrated Lewis pair (FLP)-catalyzed reduction of Michael acceptors is a challenging reaction that proceeds with specific FLP structures. Kinetics and equilibrium of the reactions of two phosphines (Ar3P), namely tri(1-naphthyl)phosphine and tri(o-tolyl)phosphine, are reported with reference electrophiles. The reason for the failure of the FLPs (Ar3P/B(C6F5)3) to reduce activated alkenes under H2 pressure is shown to be a hydrophosphination process that inhibits the reduction reaction. Kinetic and thermodynamic factors controlling both pathways are discussed in light of Mayr's free linear energy relationships.
A novel bifunctional Pd-ZIF-8/rGO catalyst with spatially separated active sites for the tandem Knoevenagel condensation-reduction reaction
Wang, Hefang,Wang, Yansu,Jia, Aizhong,Wang, Cunyue,Wu, Luming,Yang, Yongfang,Wang, Yanji
, p. 5572 - 5584 (2017/12/07)
A novel bifunctional catalyst with spatially separated active sites was prepared by the immobilization of Pd nanoparticles (NPs) via covalent interaction and coordination of a zeolitic imidazolate framework (ZIF-8) on the surface of graphene oxide (GO), respectively, which was used as an efficient catalyst for the Knoevenagel condensation-reduction tandem reaction. The results of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Raman spectroscopy, UV-vis spectroscopy, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) demonstrated that Pd and ZIF-8 were successfully immobilized on the surface of GO, and the GO was reduced to reduced graphene oxide (rGO) using NaBH4 as the reductant in the preparation of Pd-ZIF-8/rGO. The textural properties and morphology of Pd-ZIF-8/rGO were characterized by N2 adsorption-desorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Pd-ZIF-8/rGO shows excellent catalytic performance in the tandem reaction with 100% benzaldehyde conversion and 98.3% selectivity to benzylmalononitrile. The excellent catalytic performance of Pd-ZIF-8/rGO in the tandem reaction is due to the high catalytic activities of spatially separated Pd NPs and ZIF-8 active sites and concentrated reactants on the surface of Pd-ZIF-8/rGO due to the π-π interaction between rGO and the reactants. The anchoring and stabilization effects of oxygenated groups of GO inhibit the aggregation and leakage of active sites, leading to good catalytic recyclability with almost unchanged catalytic activity for more than eight cycles in the tandem reaction.
Base-Promoted Cascade Approach for the Preparation of Reduced Knoevenagel Adducts Using Hantzsch Esters as Reducing Agent in Water
He, Tao,Shi, Ronghua,Gong, Yimou,Jiang, Guangyou,Liu, Ming,Qian, Shan,Wang, Zhouyu
supporting information, p. 1864 - 1869 (2016/07/16)
A cascade Knoevenagel condensation-reduction approach, which was carried out in water, has been reported. Using Hantzsch esters as reducing agent, under the promotion of base, a variety of reduced Knoevenagel adducts could be easily prepared by direct alkylation of malononitrile, ethyl 2-cyanoacetate, and 2-(4-nitrophenyl)acetonitrile, respectively. Meanwhile, a gram-scale synthesis of the protocol was also realized with excellent isolated yield.
Synthesis and biocatalytic ene-reduction of Knoevenagel condensation compounds by the marine-derived fungus Penicillium citrinum CBMAI 1186
Jimenez, David E.Q.,Ferreira, Irlon M.,Birolli, Willian G.,Fonseca, Luis P.,Porto, André L.M.
, p. 7317 - 7322 (2016/10/29)
The chemoselective bioreduction of α,β-unsaturated compounds is an important synthetic tool that can have applications in the synthesis of many fine chemicals and pharmaceutical molecules. The synthesis of aromatic malononitrile derivatives through Knoevenagel condensation by microwave radiation under green chemistry conditions using methanol like solvent, free base and free catalyst is here reported. In addiction the biocatalytic reduction of the C–C double bond of aromatic malononitrile derivatives by whole cells of the marine-derived fungal Penicillium citrinum CBMAI 1186 was also tested. The products catalyzed by the fungus ene-reductase were obtained in very good yields (up to >98%).
A convenient heterogeneous reduction of knoevenagel product by Hantzsch ester and its development into reductive alkylation of malononitrile
Yang, Yong-Qing,Lu, Zheng
, p. 650 - 653 (2014/07/22)
Poor solubility of Hantzsch ester is used as indicator in the reduction of methylidene malononitrile. The Knoevenagel reaction is integrated to develop a reductive alkylation of malononitrile with aryl and aliphatic aldehyde as the carbonyl substrate. Cop
Discovery of mixed type thymidine phosphorylase inhibitors endowed with antiangiogenic properties: Synthesis, pharmacological evaluation and molecular docking study of 2-thioxo-pyrazolo[1,5-a][1,3,5]triazin-4-ones. Part II
Bera, Hriday,Ojha, Probir Kumar,Tan, Bee Jen,Sun, Lingyi,Dolzhenko, Anton V.,Chui, Wai-Keung,Chiu, Gigi Ngar Chee
, p. 294 - 303 (2014/04/17)
In our drug discovery program, a series of 2-thioxo-pyrazolo[1,5-a][1,3,5] triazin-4-ones were designed, synthesized and evaluated for their TP inhibitory potential. All the synthesized analogues conferred a varying degree of TP inhibitory activity, comparable or better than positive control, 7-deazaxanthine (7-DX, 2) (IC50 value = 42.63 μM). A systematic approach to the lead optimization identified compounds 3c and 4a as the most promising TP inhibitors, exhibiting mixed mode of enzyme inhibition. Moreover, selected compounds demonstrated the ability to attenuate the expression of the angiogenic markers (viz. MMP-9 and VEGF) in MDA-MB-231 cells at sublethal concentrations. In addition, molecular docking studies revealed the plausible binding orientation of these inhibitors towards TP, which was in accordance with the experimental results. Taken as a whole, these compounds would constitute a new direction for the design of novel TP inhibitors with promising antiangiogenic properties.
An efficient green multi-component reaction strategy for the synthesis of highly functionalised pyridines and evaluation of their antibacterial activities
Reddy, Lakkireddy Srinivasula,Reddy, Tirumalareddy Ram,Mohan, Reddy Bodireddy,Mahesh, Avula,Lingappa, Yeramanchi,Reddy, Nallagondu Chinna Gangi
, p. 1114 - 1120 (2014/01/06)
An efficient green multi-component reaction (MCR) method has been developed for the synthesis of 2-amino-4-aryl/heteroaryl-6-(pyridin-2-ylthio)pyridine-3, 5-dicarbonitrile(s) via a 3-component reaction of aryl aldehyde(s), malononitrile and 2-mercaptopyridine in the presence of K2CO 3 under solvent free reaction conditions (SFRC) using grinding technique at room temperature in a single step. The advantages of the present protocol is operationally simple, environmentally benign, solvent-free reaction conditions (SFRC), simple work up, excellent isolated yields of desired products and viable method for large scale applications in pharmaceutical industry. Interestingly, the synthesized compounds showed moderate to excellent antibacterial activities against Gram-positive and Gram-negative bacterial strains.
