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1.
CuO–CeO2 is reported as a highly efficient and green recyclable catalyst,for the multicomponent synthesis of 4H-benzo[b]pyran derivatives.The catalyst was synthesized by a co-precipitation method and characterized by XRD,BET specific surface area,ESEM and EDS analysis.This synthetic method provides several advantages such as simple work-up procedures,minimal amount of waste generated,short reaction time,and high yields of products. 相似文献
2.
In this work, titanomagnetite nanoparticles (Fe3-xTixO4) have been used as a novel suppport for the synthesis of a magnetic acidic catalyst. These nanoparticles were functionalized with sulfonic acid groups to prepare the Fe3-xTixO4@SO3H nanoparticles. The synthesized acidic nanoparticles have been explored as new and efficient recyclable heterogeneous catalyst for a one-pot, three-component synthesis of tetrahydrobenzo[b]pyrans known as 4H-chromenes and 1,4-dihydropyrano[2,3-c]pyrazoles. The structure of the catalyst was established by infrared, energy dispersive x-ray (EDX), and scanning electron microscopy analyses. The reactions proceed smoothly to furnish the respective products in excellent yields and short reaction times. The facile reaction conditions, easy isolation of the products, versatility, and easy magnetic separation and reusability of the catalyst with no significant loss of activity are the main merits of the present method. 相似文献
3.
Shahnaz Rostamizadeh Nasrin Shadjou Ali Mohammad Amani Saeed Balalaie 《中国化学快报》2008,19(10):1151-1155
A simple and efficient procedure for the preparation of aryl- 14-H-dibenzo [aj]xanthenes by a one-pot condensation reaction of 2-naphthol and aryl aldehydes, in the presence of silica supported sodium hydrogen sulfate (NaHSO4/SiO2) as a catalyst and in the absence of solvent has been developed. The present method offers several advantages such as excellent yields, short reaction time (10-30min), mild condition, simple work-up, and the use of a cheap and environmentally friendly catalyst with remarkable reusability. 相似文献
4.
《Arabian Journal of Chemistry》2020,13(1):290-297
A simple, facile and efficient method has been developed for the Friedel–Crafts benzoylation of arenes using magnetic γ-Fe2O3 nanoparticles under solvent-free sonication. The γ-Fe2O3 nanoparticles were used as an efficient and magnetically recoverable catalyst for the synthesis of aromatic ketones in good to excellent yields at room temperature under solvent-free. The reaction occurred with high regioselectivity under mild condition. The magnetic γ-Fe2O3 nanoparticles are economically synthesized in large-scale, easily separated from the reaction mixture by an external magnet and able to be reused several times without significant loss of the catalytic performance, which make them easy application to industrial processes. 相似文献
5.
Leimajam Vartima Chanu Thokchom Prasanta Singh Laishram Ronibala Devi 《Green Chemistry Letters and Reviews》2018,11(3):352-360
We are reporting a simple, efficient and green protocol for the synthesis of chromenes and dihydropyrimidines (products of Knoevenagel and Biginelli reaction, respectively) by the use of silica-supported perchloric acid (HClO4–SiO2) as an effective heterogeneous catalyst. Short reaction times, high product yields, simple procedure and reusability of the catalyst are the superior characteristics of this protocol. 相似文献
6.
Lingxiang Bao Zongbao Yu Teng Fei Zhiyuan Yan Jiazhe Li Chenghui Sun Siping Pang 《应用有机金属化学》2020,34(6):e5607
Sustainable development demands an environmentally friendly and efficient method for the hydrogenation of organic molecules, including the hydrogenation of functionalized nitroarenes. In this study, a highly active and selective metal–organic framework-supported palladium catalyst was prepared for the catalytic hydrogenation of nitroarenes. High selectivity (>99%) and excellent yield (98%) of aniline were realized after 2 hours in ethanol under hydrogen (1 atm) at room temperature. The reductions were successfully carried out in the presence of a wide range of other reducible functional groups. More importantly, the catalyst was very stable without the loss of its catalytic activity after five cycles. 相似文献
7.
Several air and moisture stable Pd(II) pincer complexes were synthesized via oxidative addition of Pd(0) to novel PheBox pincer ligand precursors. Low loadings (1 mol%) of the Pd complex [t-BuPhebox-Me(2)]PdBr are capable of efficiently promoting the selective α-monoarylation of a variety of ketones with numerous aryl bromides in only 1 h at 70 °C with 82-99% yields. 相似文献
8.
Faroughi Niya Homayoun Hazeri Nourallah Rezaie Kahkhaie Mahboobeh Maghsoodlou Malek Taher 《Research on Chemical Intermediates》2020,46(3):1685-1704
Research on Chemical Intermediates - In this study, an efficient and novel procedure has been reported for loading sulfanilic acid on the surface of magnetite Fe3O4 nanoparticles using... 相似文献
9.
H-ZSM5 is applied as an efficient, highly reusable, and heterogeneous catalyst for the oxidation of sulfides to sulfoxides using 30% H2O2 under solvent-free conditions at room temperature. A variety of aromatic and aliphatic sulfides with different functional groups were successfully oxidized with good to excellent yields in short reaction times. The catalyst can be easily recovered by simple filtration and recycled for several consecutive runs without any significant loss of its catalytic activity. 相似文献
10.
In the present work, Fe3O4@L-Tyrosine-Pd heterogeneous nanocatalyst was prepared by a simple and inexpensive procedure. The prepared nanocatalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray Diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), inductively coupled plasma optical emission spectroscopy (ICP-OES), scanning electron microscopy (SEM), Transmission electron microscopy)TEM(, X-ray mapping, thermal gravimetric analysis (TGA), N2 adsorption and desorption (BET) and vibrating sample magnetometer (VSM) techniques. Besides, it was employed as an efficent catalyst for C-C cross coupling and S-arylation reactions under green conditions. The optimized conditions for these reactions are described. The heterogeneous catalyst can be easily separated by applying a simple magnet and can also be reused in several consecutive runs without appreciable change in its catalytic activity. 相似文献
11.
H.Nagabhushana S.Sandeep Saundalkar L.Muralidhar B.M.Nagabhushana C.R.Girija D.Nagaraja M.A.Pasha V.P.Jayashankara 《中国化学快报》2011,22(2):143-146
This paper describes the combustion synthesis ofα-Fe2O3 nanopowder at much lower temperature and its catalytic activity for the one-pot preparation of 3,4-dihydropyrano[c]chromenes.The combustion derivedα-Fe2O3 nanopowder was characterized by powder X-ray diffraction(PXRD),Braunauer,Emmett and Teller(BET) surface area,scanning electron microscopy(SEM) and Fourier transform infrared spectroscopy(FTIR).Highly efficient,three-component condensation of aromatic aldehyde,malanonitrile and 4- hydroxycoumarin catalyzed byα-Fe2O3 nanoparticles at room temperature is described.The method offers an excellent alternative to the synthesis of 3,4-dihydropyrano[c]chromenes.The reactions are rapid,clean,and the products with good yield and high purity. 相似文献
12.
Chromene substructure is an important structural motif present in a variety of medicines, natural products, and materials showing biological activities. Here, a simple and convenient procedure for the synthesis of 3,4-dihydropyrano[3,2-c]chromene derivatives is described. For this purpose, Fe3O4 nanoparticles supported on β-cyclodextrin-guanidine were successfully prepared and used as catalyst. The structure of this catalyst was assigned by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermal gravimetric analysis, and vibrating sample magnetometer techniques. The prepared nanocomposites were used as a highly active, heterogeneous, and reusable nanocatalyst for the one-pot, three-component reaction of 4-hydroxycoumarin, aromatic aldehydes, and ethyl cyanoacetate. This method has advantages such as mild conditions, high yields, easy workup and simple purification of products, little catalyst loading, cost efficiency, and reusability of the catalyst. 相似文献
13.
Peng Li Sridhar Regati Hui-Cai Huang Hadi D.Arman Bang-Lin Chen John C.-G.Zhao 《中国化学快报》2015,26(1):6-10
A new highly efficient and reusable Cu(Ⅰ)-MOF has been developed for the synthesis of propargylamine compounds via the three-component reaction of secondary amines,alkynes.and aromatic aldehydes under solvent-free conditions.The desired propargylamines were obtained in good to excellent yields with a low catalyst loading.The catalyst may be recovered and reused for up to 5 cycles without major loss of activity.This protocol has the advantages of excellent yields,low catalyst loading,and catalyst recyclability. 相似文献
14.
Various biologically important perimidine derivatives have been synthesized efficiently from various ketones and naphthalene1,8-diamine by using a catalytic amount of RuC13 (1 mol%). This method is a very simple and high yielding reaction for the synthesis of perimidine derivatives. 相似文献
15.
I. V. Babichev A. A. Ilyin R. N. Rumiantsev A. P. Ilyin M. V. Dremin 《Russian Journal of Applied Chemistry》2016,89(2):227-232
X-ray phase analysis, synchronous thermal analysis, and IR spectroscopy were used to study the process in which an iron-molybdenum catalyst for partial oxidation of methanol to formaldehyde is prepared. The influence exerted by the pH of the medium on the composition, structure, and properties of the oxide Fe–Mo catalyst was examined. It was found that the amount of the active component in a sample obtained at pH 2 is the largest, and the sample exhibits the best activity in the reaction of methanol oxidation to formaldehyde. The possibility was examined of the occurrence of side reactions in which carbon monoxide is converted. It was found that the conversion occurs only on samples obtained at pH > 2. 相似文献
16.
Mohsen Esmaeilpour Jaber Javidi Elahe Rezaei 《Phosphorus, sulfur, and silicon and the related elements》2017,192(5):530-537
An efficient and environment friendly process for the synthesis of α-aminophosphonates has been devised. Through a one-pot three-component condensation of various aldehydes, amines, and triethyl phosphite in the presence of Fe3O4@SiO2-imid-PMAn nanoparticles as magnetic catalysts under solvent-free conditions and ultrasonic irradiation, α-aminophosphonates were obtained with excellent yields. The reactions under solvent-free conditions at room temperature are compared with the ultrasonic-assisted reactions. This new procedure has notable advantages such as short reaction time, excellent yields, easy purification, and the absence of any tedious workup or purification. The aforementioned catalyst could be easily recovered by an external magnetic field and can be reused for six consecutive reaction cycles without significant loss of activity. In addition, SEM and DLS of the catalyst after the reaction cycle were investigated. 相似文献
17.
Graphene (G) supported Pd–Co bimetallic nanoparticles (NPs) as a highly active catalyst was prepared by a chemical reduction method and used for coupling reactions. With the characterization of X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and Raman spectrum, the composition of resulting Pd–Co material was identified to be alloy structural. The Pd–Co (1:1)/G exhibited the highest catalytic activity for the Sonogashira-type coupling reactions and also exerted satisfied catalytic activity and recycle stability for Suzuki–Miyaura cross-coupling reactions. This Pd–Co/G material also possessed other advantages such as low-cost, easy recycled from reaction system by a magnet for their magnetic property, and easy experimental handling. 相似文献
18.
Wang Junru Zhou Yucheng Shao Yamin He Feng Wu Min Ni Henmei Zheng Yingping Sun Yueming 《Research on Chemical Intermediates》2019,45(4):1721-1735
Research on Chemical Intermediates - Hybrid materials of chitosan–silica (CS–SiO2) with nonprecious-metallic ions (Cu) immobilized on (Cu–M@CS–SiO2) were developed as green... 相似文献
19.
Felipe Wodtke Fernando R. Xavier Samuel R. Mendes Alfredo R.M. de Oliveira Rogério A. Gariani 《Tetrahedron letters》2017,58(3):231-234
A novel application of the highly stable niobium oxide phosphate (NbOPO4) as an efficient catalyst for the synthesis of β-enamino ketones under solvent-free conditions is described. This protocol, exhibits attractive yields, short reaction periods, lower loading of catalyst and high chemoselectivity. 相似文献
20.
Guezane Lakoud Samia Merabet-Khelassi Mounia Aribi-Zouioueche Louisa 《Research on Chemical Intermediates》2016,42(5):4403-4415
Research on Chemical Intermediates - Nickel (II) sulfate hexahydrate is used for the first time as an efficient catalyst for the one-pot synthesis of α-aminophosphonates by three-component... 相似文献