共查询到20条相似文献,搜索用时 45 毫秒
1.
Majid Moghadam Shahram Tangestaninejad Valiollah Mirkhani Iraj Mohammadpoor-Baltork Saeedeh Gorjipoor Parvin Yazdani 《合成通讯》2013,43(3):552-561
Efficient ring opening of epoxides with aromatic amines catalyzed by ZrO(OTf)2 is reported, and the corresponding β amino (beta-amino acid) alcohols were obtained in high yields in CH3CN as solvent. The reactions were carried out at room temperature and in the presence of only 1.25 mol% of ZrO(OTf)2. This catalyst can be reused several times without loss of its activity. 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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Santosh Kumar Giri Monika Verma K. P. Ravindranathan Kartha 《Journal of carbohydrate chemistry》2013,32(8-9):464-478
Indium(III) trifluoromethanesulfonate has been found to be extremely efficient in catalyzing acyl transfer reactions of various carbohydrates and their derivatives. Selective acetolyses of certain benzyl ethers/isopropylidene acetals of sugars have been possible using In(OTf)3 in Ac2O (neat). Reaction of the per-O-acetate of 2-deoxy-2-phthalimido-D-glucose with benzyl mercaptan in the presence of In(OTf)3 led to the formation of the corresponding thioglycoside in high yield. Facile formation and hydrolysis of the isopropylidene and benzylidene acetals of various carbohydrates have also been achieved very efficiently in the presence of In(OTf)3. The results show great promise for In(OTf)3 in synthetic carbohydrate chemistry. 相似文献
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A simple and general method has been developed for the one-pot, three-component synthesis of a variety of primary 1-aminophosphonates catalyzed by Al(OTf)3 under solvent-free conditions in good to high yields. 相似文献
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Iraj Mohammadpoor-Baltork Majid Moghadam Valiollah Mirkhani Shahram Tangestaninejad Hamid Reza Tavakoli 《中国化学快报》2011,22(1):9-12
An efficient,convenient and green method has been introduced for the preparation of 14-aryl(alkyl)-14H-dibenzo[a,j]xanthene and 1,8-dioxooctahydroxanthene derivatives by the reaction of aldehydes with 2-naphthol and 5,5-dimethyl-1,3-cyclohexanedione, respectively,in the presence of ZrO(OTf)2 as a reusable catalyst under solvent-free conditions.In addition,very short reaction times, excellent yields,straightforward procedure,and relatively non-toxicity of the catalyst are other noteworthy advantages of the present method. 相似文献
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A new and efficient method for the synthesis of benzoxazoles, benzothiazoles, benzimidazoles from reactions of o‐substituted aminoaromatics with orthoesters in the presence of catalytic amounts of Ga(OTf)3 under solvent‐free conditions is presented. The remarkable features of this new protocol are high conversion, very short reaction times, cleaner reaction profiles under solvent‐free conditions, straight forward procedure, and use of relatively non‐toxic catalysts. 相似文献
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Monica Nardi Sonia Bonacci Natividad Herrera Cano Manuela Oliverio Antonio Procopio 《Molecules (Basel, Switzerland)》2022,27(5)
The benzimidazole ring of the heterocyclic pharmacophores is one of the most widespread and studied systems in nature. The benzimidazole derivative synthesis study is a crucial point for the development of a clinically available benzimidazole-based drug. Here, we report a simple microwave assisted method for the synthesis of 1,2-disubstituted benzimidazoles. The combination of the molar ratio of N-phenyl-o-phenylenediamine:benzaldehyde (1:1) using microwave irradiation and only 1% mol of Er(OTf)3 provides an efficient and environmental mild access to a diversity of benzimidazoles under solvent-free conditions. The proposed method allows for the obtainment of the desired products in a short time and with very high selectivity. 相似文献
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A mild and efficient procedure for synthesis of β-enaminones by the condensation of β-dicarbonyl compounds and amines using ytterbium triflate [Yb(OTf)3] as catalyst is described. The catalyst can be easily recovered and reused without loss of activity. 相似文献
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Various biologically important perimidine derivatives have been efficiently synthesized in excellent yields using naphthalene‐1,8‐diamine with various ketones in the presence of a catalytic amount of Yb(OTf)3. The influence of the loading of Yb(OTf)3, reaction solvent, the structure of ketones was studied. This method is a very easy, simple and high yielding reaction for the synthesis of perimidine derivatives. 相似文献
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M. Mller R. Knge J. L. Hedrick 《Journal of polymer science. Part A, Polymer chemistry》2000,38(11):2067-2074
A general and novel method for the controlled synthesis of aliphatic polyesters is presented. The evaluation of stannous (II) trifluoromethane sulfonate [Sn(OTf)2] and scandium (III) trifluoromethane sulfonate [Sc(OTf)3] as catalysts for the ring‐opening polymerization (ROP) of various lactones is described as a route to polyesters under mild and highly selective polymerization conditions. Size exclusion chromatograms of poly(ϵ‐caprolactone) initiated from ethanol in the presence of either Sn(OTf)2 or Sc(OTf)3 demonstrate the facile synthesis of narrowly dispersed products. Predictable molecular weights, typical of a living or controlled polymerization, were obtained with high yields. These catalysts are versatile and applicable toward the ROP of other cyclic (di)esters, including β‐butyrolactone, which produces the synthetic analogue of the biopolymer poly(β‐hydroxybutyrate). © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2067–2074, 2000 相似文献
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Shrinivas S. Kottawar Shaphi A. Siddiqui Vishal P. Chavan Wamanrao N. Jadhav 《合成通讯》2013,43(19):3546-3549
An efficient synthesis of substituted 1-pyridylimidazo-[1,5-a]-pyridines has been accomplished using scandium(III) triflate as catalyst under mild conditions in excellent yields. 相似文献
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The reaction of various chiral 2,2′-diaryldialdehydes with achiral and chiral 1,2-diamines in the presence of Lewis acids to give imidazo[1,2-a]azepines was investigated. Best results were achieved with Yb(OTf)3; the reaction outcome is strongly dependent upon the geometric features of both reactants. Kinetic resolution of rac-2,2′-dinaphthyldialdehyde with (R,R)-1,2-diphenyl-1,2-diamminoethane (up to 92% e.e.) was achieved. 相似文献
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Dysprosium(III) triflate is found to catalyze efficiently the coupling of 4-hydroxyproline with indeno[1,2-b]quinoxalin-11-one and isatin derivatives under mild conditions to produce 11-(1H-pyrrol-1-yl)-11H-indeno[1,2-b]quinoxalin-11-one and 3-(1H-pyrrol-1-yl)indolin-2-one derivatives, respectively, in excellent yields in short reaction times. A comparative study with both InCl3 and Dy(OTf)3 is described. 相似文献
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o-Phenylenediamines were reacted with carbonyl compounds, β-ketoesters, and 1,2-diketones in presence of ammonium salts to give benzimidazoles and quinoxalines in very good yields. Ammonium salts are commercial and environmentally benign catalysts. 相似文献
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Kaveh Parvanak Boroujeni 《合成通讯》2013,43(2):277-284
Cross-linked polystyrene-supported aluminium triflate [Ps-Al(OTf)3] has been shown to be a mild, efficient, and chemoselective heterogeneous Lewis acid catalyst for acetylation of aldehydes with acetic anhydride. The catalyst can be recovered simply and reused efficiently at least five times without any noticeable loss of catalytic activity. 相似文献