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1.
《Tetrahedron letters》2019,60(46):151259
Phenoxathiin and its derivatives have attracted a great deal of interest due to their unique chemical and physical properties and their applications in fluorescent materials, antifungal activities and selective inhibitors. In the presence of copper supported on manganese oxide-based octahedral molecular sieves OMS-2 (CuOx/OMS-2), the heterogeneously catalytic synthesis of phenoxathiinan derivatives via intramolecular arylations of phenols with aryl bromide or aryl chloride has been achieved. TEM and XRD have confirmed the CuOx/OMS-2 catalyst has been successfully reused 8 times without a significant decrease in the yield, with simple filtration and washing as a means of separation. 相似文献
2.
An inexpensive, efficient and environmentally friendly copper(II) catalyst supported on polystyrene was successfully synthesized and used as a heterogeneous catalyst for S‐arylation of potassium thiocyanate by aryl halides. Also this catalyst could be recovered and reused several times without any noticeable decrease in its catalytic activity. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
3.
A highly efficient, convenient, and environmentally friendly protocol was developed for the PdCl2-catalyzed ligandless and additive-free Suzuki reaction of aryl bromides with arylboronic acids in water/ethanol. 相似文献
4.
Eleni Vasilikogiannaki Ioannis Titilas Charis Gryparis Anastasia Louka Ioannis N. Lykakis Manolis Stratakis 《Tetrahedron》2014
1,1,3,3-Tetramethyldisiloxane (TMDS) is a highly reactive reducing reagent in the Au/TiO2-catalyzed hydrosilylation of carbonyl compounds relative to monohydrosilanes. The reduction of aldehydes or ketones with TMDS can be performed on many occasions at ambient conditions within short reaction times and at low loading levels of gold, whereas typical monohydrosilanes require excess heating and prolonged time for completion. The product yields are excellent, while almost stoichiometric amounts of carbonyl compounds and TMDS can be used. It is postulated that the enhanced reactivity of TMDS is attributed to the formation of a gold dihydride intermediate. This intermediate is also supported by the fact that double hydrosilylation of carbonyl compounds by TMDS is a negligible pathway. 相似文献
5.
Hong Yun Guo Ji Chao Li You Le Shang College of Chemical Engineering Materials Science Zhejiang University of Technology Hangzhou China 《中国化学快报》2009,(12)
A simple and efficient procedure for the synthesis of substituted benzothiazoles through condensation of 2-aminothiophenol with aromatic aldehydes in the presence of H_2O_2/HCl system in ethanol at room temperature is described.The target compounds have been characterized by ~1H NMR,~(13)C NMR,IR and MS.Short reaction time,easy and quick isolation of the products,and excellent yields are the main advantages of this procedure. 相似文献
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7.
Gianluca Bianchini Francesco De Angelis Raffaele Saladino 《Tetrahedron letters》2005,46(14):2427-2432
A convenient and efficient C-H insertion reaction of environment friendly H2O2 into representative hydrocarbon derivatives by homogeneous methyltrioxorhenium (MTO), heterogeneous poly(4-vinylpyridine)/methyltrioxorhenium (PVP/MTO) and microencapsulated polystyrene/methyltrioxorhenium (PS/MTO) systems in ionic liquids, is described. In some cases a higher activity was observed if compared with the same reaction in molecular solvents. The heterogeneous catalysts are stable systems under the reaction conditions and can be recycled for more transformations. 相似文献
8.
A heterogeneous catalyst, nanosized MCM-41-Pd, was used to catalyze the Sonogashira coupling of aryl and heteroaryl halides with terminal alkynes in the presence of CuI and triphenylphosphine. The coupling products were obtained in high yields using low Pd loadings to 0.01 mol%, and the nanosized MCM-41-Pd catalyst was recovered by centrifugation of the reaction solution and re-used in further runs without significant loss of reactivity. 相似文献
9.
A simple and efficient procedure for the synthesis of substituted benzothiazoles through condensation of 2-aminothiophenol with aromatic aldehydes in the presence of H2O2/HCl system in ethanol at room temperature is described. The target compounds have been characterized by 1H NMR, 13C NMR, IR and MS. Short reaction time, easy and quick isolation of the products, and excellent yields are the main advantages of this procedure. 相似文献
10.
A solvent-free, eco-friendly and facile approach for the synthesis of highly functionalized tetrasubstituted pyrroles has been reported through one-pot four-component reaction of aldehyde, amine, nitroalkane and 1,3-diketone using silica gel supported polyphosphoric acid (PPA–SiO2) under microwave condition. The reaction occured through the in situ formation of β-keto enamine and nitrostyrene analog following Michael addition and finally intramolecular annulation affording the products in good yields. The key features of the present method include clean reaction, mild conditions, low catalyst loading, straightforward, high to excellent yields, short reaction time, avoiding use of harmful metal catalyst and organic solvent, environmentally friendly compared to the existing methods, recovery and reusability of catalyst and easy workup procedure. 相似文献
11.
Reductive carbonylation of aryl and heteroaryl iodides using Pd(acac)2/dppm as an efficient catalyst
Abhilash S. SinghBhalchandra M. Bhanage Jayashree M. Nagarkar 《Tetrahedron letters》2011,52(18):2383-2386
Palladium catalyzed simple and efficient protocol for reductive carbonylation of aryl and heteroaryl compounds has been developed. The formylation of aryl and heteroaryl iodides takes place in the presence of Pd(acac)2/dppm catalyst at 10 bar pressure of synthetic gas to give the desired aromatic and heteroaromatic aldehydes in good to excellent yields. Easy work-up, stability of the catalyst, low catalyst loading and less reaction time are the advantages of this method. 相似文献
12.
Mariya G. Shaibakova Leila O. KhafizovaNuri M. Chobanov Rinat R. GubaidullinNatal’ya R. Popod’ko Usein M. Dzhemilev 《Tetrahedron letters》2014
A new one-pot method for the synthesis of tetraalkyl substituted furans in 74–80% yields has been implemented via the reaction between symmetrical acetylenes, ethylaluminum dichloride, and carboxylic esters in the presence of metallic Mg as an acceptor of halide ions, catalyzed by bis(cyclopentadienyl)titanium dichloride. A mechanism for the reaction is proposed and discussed. 相似文献
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14.
The influence of Ni(acac)2 added in catalytic amounts on the chemically induced dynamic nuclear polarization (CIDNP) effects, the mechanism of interaction,
and the products of reaction between Et3Al and CCl4 were studied. The radical intermediates were identified and the routes for their transformations were proposed. The thermal
reaction of Et3Al with CCl4 occurs by a radical mechanism. However, in the presence of Ni(acac)2, the reaction proceeds mainlyvia a nonradical route and gives large amounts of ethylene and ethane.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1580–1583, August, 1998. 相似文献
15.
Nanomagnetic-supported sulfonic acid is found to be a new, powerful, and reusable heterogeneous catalyst for the rapid synthesis of 3,4-dihydropyrimidin-2-(1H)-ones under conventional heating and microwave irradiation. This is the first example of combination of magnetic iron nanoparticles and microwave technique for the multicomponent reaction. The optical behaviors of the 3,4-dihydropyrimidin-2-(1H)-ones have been investigated by UV–vis spectroscopy. 相似文献
16.
A highly efficient and regioselective allylation reaction of amines with allylic alcohols under mild conditions catalyzed by the cubane-type sulfido cluster [(Cp∗Mo)3S4Pd(dba)][PF6] with H3BO3 as an additive has been developed. A variety of amines and allylic alcohols are investigated, and in the case of allylic alcohols bearing substituents at either α- or γ-position only linear allylic amination products are obtained. 相似文献
17.
Sudip K. De Manish Bhattacharjee 《Journal of polymer science. Part A, Polymer chemistry》2009,47(23):6496-6503
[Cp2TiCl2] has been found to be an effective precatalyst for room temperature aqueous homo‐ and copolymerization of methyl methacrylate and styrene in the presence of a cocatalyst, NaBPh4 and an emulsifier, sodium n‐dodecyl sulfate. The polymers obtained are of high molecular weight with low molecular weight distribution. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6496–6503, 2009 相似文献
18.
Malek Taher Maghsoodlou Sayyed Mostafa Habibi-Khorassani Reza Heydari Nourallah Hazeri Seyed Sajad Sajadikhah Mohsen Rostamizadeh 《Arabian Journal of Chemistry》2011,4(4):481-485
An efficient and direct protocol is described for the preparation of α-amino phosphonates derivatives by employing a multi-component, one-pot condensation reaction of aldehyde, amine and trialkyl phosphite in the presence of silica-supported perchloric acid (3 mol%) under solvent-free conditions. The thermal solvent-free green procedure offers advantages such as shorter reaction time, simple work-up, high yield, recovery and reusability of catalyst. 相似文献
19.
Seied Ali Pourmousavi Shaghayegh Sadat Kazemi 《Monatshefte für Chemie / Chemical Monthly》2012,52(12):917-923
Abstract
Chemoselective and efficient thioacetalization of a variety of aldehydes was achieved in excellent yields at room temperature using 1,2-ethanedithiol in the presence of catalytic amounts of H2SO4-silica. Thioacetals were also prepared by transthioacetalization of acylals and acetals under similar conditions. 相似文献20.
Pan-Lin Shao 《Tetrahedron letters》2010,51(17):2316-1062
Chiral N-heterocyclic carbenes were found to be efficient catalysts for the formal [4+2] cycloaddition reaction of alkyl(aryl)ketenes and 9,10-phenanthrenequinone to give the corresponding cycloadducts in good yields with high enantioselectivities. 相似文献