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A simple and efficient catalytic protocol for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes via the one-pot condensation ofβ-naphthol and aryl aldehydes using silicotungstic acid(H4[SiW12O40]) is reported.The present method offers several advantages such as high to excellent yields,short reaction times,recovery and reusability of catalyst,mild reaction conditions and easy workup procedures. 相似文献
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Mohammad Abdollahi-Alibeik Safoora Poorirani 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):3182-3190
2-Substituted benzothiazoles have been efficiently synthesized in good yields by the condensation reaction of o-aminothiophenol with aldehydes in the presence of a catalytic amount of perchloric acid–doped polyaniline (HClO4/PANI). The low cost, simple recovery, and efficient reusability are remarkable characteristics of this catalyst. 相似文献
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A straightforward and effective procedure for the synthesis of 14-aryl(alkyl)-14H-dibenzo[aj]xanthenes was described using a catalytic amount of molecular iodine under microwave irradiation to afford the corresponding xanthenes in good yields. 相似文献
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《Green Chemistry Letters and Reviews》2013,6(3):433-437
Abstract A simple and efficient procedure has been developed for the preparation of aryl-14H-dibenzo[a,j]xanthenes by a one-pot condensation of 2-naphthol and aryl aldehydes, in the presence of mesoporous zirconia modified with tungstophosphoric acid (ZrTPA60BT100), to be used as a heterogeneous catalyst in a solvent-free medium using conventional heating. The present approach offers the advantages of clean reaction, simple methodology, short reaction time, and high yield. The reaction work-up is very simple and the catalyst can be easily separated from the reaction mixture and reused several times in subsequent reactions without appreciable loss of the catalytic activity. 相似文献
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Efficient method for direct preparation of 14‐aryl‐14‐H‐dibenzo[a,j]xanthenes through condensation of β‐naphthol with various aromatic aldehydes in the presence of the catalytic amount of [H—NMP]+[HSO4]? under microwave irradiation was described. This method has the advantages such as; very easy reaction workup, absolute separation of catalyst from the reaction mixture and smooth recyclability of catalyst. In this reaction 14‐aryl‐14‐H‐dibenzo[a,j]xanthenes were obtained as desired products in excellent yields and short reaction times via green and one‐pot procedure. 相似文献
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Vinod T.Kamble Bhaskar S.Davane Sanjay A.Chavan Dnyanoba B.Muley Sandeep T.Atkore 《中国化学快报》2010,21(3):265-268
<正>An efficient synthesis of tetrahydroquinoline derivatives is reported via three component coupling reactions of aldehydes and anilines with various dienophiles in the presence of a catalytic amount of perchloric acid adsorbed on silica gel(HClO_4-SiO_2) under mild reaction conditions. 相似文献
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Sharmistha Urinda Dhiman Kundu Adinath Majee Alakananda Hajra 《Heteroatom Chemistry》2009,20(4):232-234
A mild, efficient, and environment friendly method has been developed for the synthesis of 14‐alkyl or aryl‐14H‐dibenzo[a, j]xanthenes by condensation of 2‐naphthol and aldehydes in the presence of a catalytic amount of indium(III) triflate (2 mol%) in water at 100°C. Different types of aromatic and aliphatic aldehydes are used in the reaction, and in all cases the products synthesized in moderate to excellent yields. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:232–234, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20539 相似文献
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Several identification techniques have been used to study the effect of the preparation method of dealuminated Y zeolite on catalyst loading. In this paper, NaY zeolite was dealuminated by chemical operation with ethylenediaminetetraacetic acid (H4EDTA) treatment. In this method, extra-framework aluminum species removed from the supercage of zeolite and therefore increases the Si/Al ratio and pore volume. Consequently, the loading of the molybdophosphoric acid (MPA) in the supercage of zeolite is increases (0.1 g/g equal 0.049 mmol/g support) in EDTA treatment (MPA-MDAZY) in comparison with (0.0875 g/g equal 0.043 mmol/g support) in hydrothermal method (MPA-DAZY). These results were also confirmed by XRF, AAS, FTIR, SEM, BET, XRD and WDX analysis. Reducing of the reaction time and increasing of the catalytic activity of EDTA treatment toward hydrothermal method can be related to the high catalyst loading based on removing of extra-framework aluminum. The catalytic activity of two catalysts has been compared in the xanthenes synthesis reactions. 相似文献
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《Comptes Rendus Chimie》2014,17(1):41-48
A convenient and efficient direct protocol for the preparation of 14-aryl-14H-dibenzo[a,j]-xanthenes was described. The condensation of 2-naphthol with various aromatic aldehydes in the presence of a catalytic amount of [H-NMP][HSO4] as a Brønsted acidic ionic liquid under solvent-free conditions at 110 °C was described. This method has the following advantages: the reaction workup is very easy, and the catalyst is smoothly recycled to catalyze the preparation of 14-aryl-14H-dibenzo[a,j]xanthenes with high yields through a green and one-pot procedure. The corresponding products have been obtained in excellent yields, with high purity, and in short reaction times. 相似文献
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Synthesis of a New Library of Pyrano‐phenazine Derivatives via a Novel Three‐Component Protocol 下载免费PDF全文
The pyrano‐phenazine derivatives 6 were synthesized by an efficient procedure using the reaction between benzo[a]phenacin‐5‐ols with the condensation product of an aldehyde with Meldrum's acid in the presence of a catalytic amount of Et3N at ambient temperature. The procedure is very simple, and products could be separated from the reaction media by simple filtration. High functional‐group tolerance both in the benzo[a]phenazin‐5‐ol and aldehyde moieties, facile reaction procedure, medium‐to‐high yields, and simple separation of the products from the reaction media are the advantages of this route. 相似文献
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Oxalic acid as a catalyst for efficient synthesis of bis-(indolyl)methanes,and 14-aryl- 14H-dibenzo[a,j]xanthenes in water 总被引:1,自引:1,他引:0
A simple, efficient, and environment benign route was developed for the preparation of bis-(indolyl)methanes and 14-aryl-14H- dibenzo[aj]xanthenes from condensation of various aromatic aldehydes or ketones with indole, and 2-naphthol, respectively, using oxalic acid catalyst in aqueous medium. Use of cheap and easily available catalyst, better yields and simple reaction protocol are the advantages of the present method. 相似文献
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A simple,efficient,and environment benign route was developed for the preparation of bis-(indolyl)methanes and 14-aryl-14H-dibenzo[a,j]xanthenes from condensation of various aromatic aldehydes or ketones with indole,and 2-naphthol,respectively,using oxalic acid catalyst in aqueous medium.Use of cheap and easily available catalyst,better yields and simple reaction protocol are the advantages of the present method. 相似文献
16.
A new, mild, and efficient method has been developed for the one‐pot synthesis of 14‐aryl or alkyl‐14H‐dibenzo[a,j]xanthenes by condensation of 2‐naphthol and aryl or alkyl aldehydes in the presence of a catalytic amount of cross‐linked polystyrene‐supported aluminum chloride (PS/AlCl3) as an ecofriendly heterogeneous catalyst. This polymeric solid acid catalyst is stable and can be easily recovered and reused without appreciable change in its activity. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 22:51–54, 2011; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20655 相似文献
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A simple and facile synthesis of 14-aryl and alkyl-14H-dibenzo[a,j]xanthenes and 1,8-dioxooctahydroxanthene derivatives has been successfully developed by treatment of β-naphthol or dimedone with aldehydes under mild conditions in the presence of a pentafluorophenyl ammonium triflate(PFPAT) organocatalyst.These catalytic condensation reactions represent green chemical processes and the PFPAT organocatalyst is air-stable,cost-effective,easy to handle,and easily removed from the reaction mixtures. 相似文献
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Maria Bełtowska-Brzezinska Tomasz Węsierski 《Journal of Solid State Electrochemistry》2013,17(7):1815-1822
The catalytic reduction of ethene, propene and 1-butene on a polycrystalline Pt electrode in strongly acidic medium containing Mo(VI) oxo-species has been examined by cyclic voltammetry taking into account the influence of perchloric acid and molybdate concentration as well as that of the scan rate on the cathodic current response. About tenfold increase in the reaction rate of each alkene investigated has been achieved at the optimum molybdate concentration of 1–2.5 mM in 4-M HClO4 solution as a supporting electrolyte in comparison with that obtained in the absence of Mo(VI) oxo-species. It was ascertained that the catalytic reduction current strongly depends on the amount of cationic Mo(VI) oxo-species at the Pt electrode/solution interface. Simultaneously, the electroreduction of cationic Mo(VI) oxo-species was found to be effectively enhanced in the presence of alkene. According to the proposed reaction pathways, alkenes are reduced to alkanes via a non-faradaic reaction with Mo(V) and/or Mo(III) cationic moieties formed in the preceding reductive electron-transfer steps from the parent cationic Mo(VI) oxo-species. Continuous regeneration of the electroactive Mo(VI) and/or Mo(V) cationic oxo-species accounts for the observed catalytic phenomenon. 相似文献
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Chao Hong Jiaqi Ma Meichao Li Liqun Jin Xinquan Hu Weimin Mo Baoxiang Hu Nan Sun Zhenlu Shen 《Tetrahedron》2017,73(21):3002-3009
A simple catalytic oxidation system was developed for the selective aerobic oxidation of structurally diverse benzylic sp3 CH bonds of ethers and alkylarenes. The reactions were performed with Fe(NO3)3·9H2O as the catalyst, KPF6 as the additive and molecular oxygen as the terminal oxidant without any ligands. Under the optimal reaction conditions, a number of isochromans, xanthenes and thioxanthenes can be converted to their corresponding esters or ketones in good to excellent yields. 相似文献