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排序方式: 共有136条查询结果,搜索用时 15 毫秒
1.
Caesium carbonate supported on hydroxyapatite‐encapsulated Ni0.5Zn0.5Fe2O4 nanocrystallites as a novel magnetically basic catalyst for the one‐pot synthesis of pyrazolo[1,2‐b]phthalazine‐5,10‐diones 下载免费PDF全文
Behrooz Maleki Samaneh Barat Nam Chalaki Samaneh Sedigh Ashrafi Esmail Rezaee Seresht Farid Moeinpour Amir Khojastehnezhad Reza Tayebee 《应用有机金属化学》2015,29(5):290-295
A novel nanomagnetic basic catalyst of caesium carbonate supported on hydroxyapatite‐coated Ni0.5Zn0.5Fe2O4 magnetic nanoparticles (Ni0.5Zn0.5Fe2O4@HAP‐Cs2CO3) was prepared. This new catalyst was fully characterized using Fourier transform infrared spectroscopy, transmission and scanning electron microscopy, X‐ray diffraction and vibrating sample magnetometry techniques, and then the catalytic activity of this catalyst was investigated in the synthesis of 1H‐pyrazolo[1,2‐b]phthalazine‐5,10‐dione derivatives. Also, Ni0.5Zn0.5Fe2O4@HAP‐Cs2CO3 could be reused at least five times without significant loss of activity and could be recovered easily by applying an external magnet. Thus, the developed nanomagnetic catalyst is potentially useful for the green and economic production of organic compounds. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
2.
Xiaoxia Yang Hongyan Xie Zhiguang Xu Jiabing Feng Qiwei Fu Haidong Li Yongtang Jia 《Journal of polymer science. Part A, Polymer chemistry》2021,59(9):813-823
An efficient, atom-economic, oxygen-tolerant, and water-tolerant strategy has been established to synthesize cyano-rich polyesters. Four kinds of organic bases, 1,1,3,3-tetramethylguanidine (TMG), 4-dimethylaminopyridine, triethylamine, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) were explored for accelerating Michael addition polymerization of malononitrile and 1,4-butandiol diacrylate. TMG can promote the polymerization efficiently under mild conditions to quantitatively afford polyester with high-molecular weight and moderate polydispersity. The comparison of the kinetic studies of TMG and TBD reveals that TMG shows better catalytic performance, while the catalysis of TBD brings about oligomers in spite of the higher efficiency at early age of the polymerization. Moreover, other diacrylate compounds could also be quantitatively polymerized to afford polyesters with high molecular weight. When dimethacrylate is chose as the monomer, the polymerization becomes sluggish. All the afforded polyesters display programmable thermal and mechanical properties that are closely related to their chemical structures. 相似文献
3.
《Journal of Saudi Chemical Society》2022,26(1):101399
Ionic liquid functional MCM-41 was synthesized, characterized and used as heterogeneous catalyst for the Knoevenagel condensation of isatins with malononitrile. A series of corresponding isatylidene malononitrile were obtained in high isolated yield (96–99%) at room temperature in a short time. The heterogeneous catalyst can be easily recovered by centrifugation and showed almost no loss of activity over 10 recycle experiments. At the same time, the gram-scale experiments showed excellent yields and provided a highly effective method for scale up applications. 相似文献
4.
Chiral Bis(imidazolidine)‐Derived NCN Pincer Rh Complex for Catalytic Asymmetric Mannich Reaction of Malononitrile with N‐Boc Imines 下载免费PDF全文
Prof. Dr. Takayoshi Arai Takuma Moribatake Prof. Dr. Hyuma Masu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(30):10671-10675
Chiral bis(imidazolidine)‐derived NCN–rhodium complexes ([PhBidine‐RhX2] and [tBu‐PhBidine‐RhX2]) were prepared by a C?H insertion method, and the structures were unequivocally determined by X‐ray crystallographic analysis. The [tBu‐PhBidine‐Rh(OAc)2] complex smoothly catalyzed an asymmetric Mannich reaction of malononitrile with N‐Boc imines to give products in up to 94 % ee, which are useful for the synthesis of chiral α‐amino acids. 相似文献
5.
Elham Kanaani 《合成通讯》2017,47(14):1326-1331
A series of novel dihydroquinoline derivatives were synthesized using malononitrile, 2-aminobenzoic acid, and benzaldehydes in the presence of a catalytic amount of acetic acid, without the use of any additional cocatalyst, under solvent-free conditions. The reaction is characterized by high efficiency, easy workup, simple purification of the products, and availability of catalyst. 相似文献
6.
Zn( L‐proline)2 as a powerful and reusable organometallic catalyst for the very fast synthesis of 2‐amino‐4H‐benzo[g]chromene derivatives under solvent‐free conditions 下载免费PDF全文
An efficient route for the synthesis of 2‐amino‐4H‐benzo[g]chromenes via a three‐component coupling reaction of aldehydes, malononitrile and 2‐hydroxy‐1,4‐naphthaquinone in the presence of Zn( L ‐proline)2 is reported. High yields, short reaction times, non‐toxicity and recyclability of the catalyst, and easy work‐up are the main merits of this protocol. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
7.
Fathy Fahim Abdel-latif 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):145-148
Abstract New spirothiopyran-4-yl indolidene derivatives have been synthesised via a facile one-step method. Structures and reaction mechanisms are also reported and supported by another synthetic route. 相似文献
8.
Ahmed M. El-Sayed 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2709-2723
Some new chromeno[2,3-b]pyrimidines, chromeno[3,2-c]pyridines, chromeno[2,3-b]pyridines and 3-chromenyl-1,3-thiazines were synthesized via the synthetic studies of the reaction of 2-imino-2H-chromen-3-thiocarboxamide with some aromatic aldehydes, active nitriles, and their ylidene derivatives. 相似文献
9.
Anastasiya V. Igushkina Alexander A. Golovanov Irina A. Boyarskaya Ilya E. Kolesnikov Aleksander V. Vasilyev 《Molecules (Basel, Switzerland)》2020,25(24)
Reaction of linear conjugated enynones, 1,5-diarylpent-2-en-4-yn-1-ones, with malononitrile in the presence of lithium diisopropylamide LDA, as a base, in THF at room temperature for 3–7 h resulted in the formation of the product of dimerization, multisubstituted polyfunctional cyclohexanes, 4-aryl-2,6-bis(arylethynyl)-3-(aryloxomethyl)-4-hydroxycyclohexane-1,1-dicarbonitriles, in yields up to 60%. Varying the reaction conditions by decreasing time and temperature and changing the ratio of starting compounds (enynone and malononitrile) allowed isolating some intermediate compounds, which confirmed a plausible reaction mechanism. The relative stability of possible stereoisomers of such cyclohexanes was estimated by quantum chemical calculations (DFT method). The obtained cyclohexanes were found to possess photoluminescent properties. 相似文献
10.
不同方法合成的沸石咪唑酯骨架结构材料(ZIF-8)的表征和催化性能 总被引:1,自引:0,他引:1
以二甲基咪唑为有机连接体和以Zn(OH)2或Zn(NO3)2·6H2O为Zn源,在甲醇与氨水的混合溶液、甲醇和DMF 3种不同的合成体系中合成了沸石咪唑酯骨架结构材料ZIF-8(分别记为ZIF-8(NH4OH)、ZIF-8(MeOH)和ZIF-8(DMF),并采用XRD、FTIR、N2吸附、SEM、TPD及Knoevenagel缩合反应等手段对所合成材料进行了表征。结果表明,采用这3种不同的合成方法均可成功制备出ZIF-8,所合成的ZIF-8的形貌基本一致,但其晶粒大小和酸碱性能有较大区别,同ZIF-8(NH4OH)和ZIF-8(DMF)相比,ZIF-8(MeOH)晶粒分布集中、平均粒径较小且具有较大的外比表面积和较多的酸碱位。不同方法合成的ZIF-8在苯甲醛和丙二腈的Knoevenagel缩合反应中的催化性能有很大差异,ZIF-8(MeOH)催化活性明显高于ZIF-8(DMF)和ZIF-8(NH4OH),其较高的催化活性,同其较大的外比表面积和酸碱性能密切相关。 相似文献