共查询到20条相似文献,搜索用时 46 毫秒
1.
Abstract A highly efficient method of synthesis of S-allyl-N-aryl dithiocarbamates using SnCl2 as a catalyst under solvent-free conditions is described. The mild reaction conditions, high yields, and shorter reaction period illustrate the good synthetic utility of this method. 相似文献
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Girdhar Joshi 《合成通讯》2013,43(5):720-728
The synthesis of benzyl alkyl ethers from benzyl bromides and alcohols using FeSO4 as a recoverable and reusable mediator has been described without use of base and cosolvent under mild conditions. 相似文献
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Stilbene derivates (stilbenoids) are present in plants and show a wide range of biological activities and potential therapeutic value. In continuation of our natural product synthesis program, an efficient, simple, and practical method has been developed to regioselectively synthesize (E)-stilbenes using H2SO4 as a catalyst in a short time (30–60 s) at room temperature in good to excellent yields.
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The TiCl4-catalyzed Friedel–Crafts reaction with trifluoroacetaldehyde ethyl hemiacetal is shown to serve as an efficient route for the synthesis of CF3-substitituted compounds of biological and synthetic importance, producing 2,2,2-trifluoroethyl phenols in good yields under mild conditions. 相似文献
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A three-component condensation reaction involving β-naphthol, aldehyde, and urea in the presence of 10 mol% thiamine hydrochloride (VB1) as a catalyst is described. Aromatic aldehydes bearing different functional groups exhibited different behavior than β-naphthol and urea under similar reaction conditions. A possible mechanism to account for the reaction is proposed. 相似文献
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Thangavel Saravanan 《合成通讯》2013,43(16):2350-2358
An efficient one-pot synthesis of α -hydroxy propargylic esters by chemoselective reduction followed by transesterification using NaBH4 in combination with CeCl3 · 7H2O is described.
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Abstract Commercially available magnesium perchlorate is reported as an extremely efficient catalyst for the ring-opening reaction of epoxide with various primary and secondary amines, especially diphenyl amine, under solvent-free conditions at room temperature. 相似文献
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Cu(ClO4) · 6H2O efficiently catalyzes the three-component Biginelli reaction of aldehyde, β-dicarbonyl compounds, and urea or thiourea under solvent-free conditions to afford the corresponding 3,4-dihydropyrimidin-2(1H)-ones in excellent yields. 相似文献
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Amines are efficiently protected as their tertiary butyloxycarbonyl (BOC) derivatives under mild reaction condition when reacted with (BOC)2O in the presence of FeCl3. The present method is applicable to a variety of amines including aliphatic, aromatic, and hetero aromatic amines. 相似文献
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L. Chakrapani 《合成通讯》2013,43(23):3442-3447
Nanocrystalline magnesium oxide (NAP-MgO) was found to be an effective heterogeneous, solid base catalyst for the direct aza-Henry reaction of nitroalkanes and various N-arylidene-4-methylbenzenesulfonamides to afford the corresponding β-nitroamines in excellent yields under mild conditions. The catalyst was recovered by simple centrifugation and reused for three cycles with consistent activity. 相似文献
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A simple, inexpensive, and efficient new synthesis of 4(3H)-quinazolinones from the reaction of 2-aminobenzamide with aroyl chlorides in the presence of two new halogen-free Brønsted acidic ionic liquids, 3-methyl-1-(4-sulfonic acid)butylimidazolium hydrogen sulfate [(CH2)4SO3HMIM][HSO4] and 1-(4-sulfonic acid) butylpyridinium hydrogen sulfate [(CH2)4SO3HPY][HSO4], green and reusable catalysts, with excellent product yields under solvent-free conditions is reported. The products could be separated simply from the catalyst, and the catalyst could be recycled without noticeably decreasing the catalytic activity. 相似文献
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An ecofriendly and efficient microwave-irradiated solvent-free benzoylation method was developed. The procedure for C-benzoylation used 50 mol% AlCl3 as a Lewis acid catalyst at 130 °C and was completed in 10 min. The isolated yield was between 71% and 100%. N-benzoylation was conducted in a catalyst-free environment at 130 °C in 10 min. The isolated yield was between 80% and 100%.
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Saikat Das Sharma 《Tetrahedron letters》2008,49(14):2216-2220
InCl3·3H2O was found to be a mild and effective catalyst for the efficient, one-pot, three component synthesis of 2,4,5-trisubstituted imidazoles at room temperature. Moreover, the utility of this protocol was further explored conveniently for the one-pot, four component synthesis of 1,2,4,5-tetrasubstituted imidazoles in high yields. 相似文献
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A general, simple, and environmentally friendly method for the direct amination of secondary benzyl alcohols with amides or 4-nitroaniline is described. This method has been applied to a variety of substrates, and the reaction proceeded smoothly at room temperature under solvent-free conditions. CbzNH2 was proved to be very useful in the direct preparation of the benzylic amines from corresponding alcohols.
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V. Srinivas 《合成通讯》2013,43(6):806-811
An efficient one-pot synthesis of 2-amino-5,10-dihydro-5,10-dioxo-4-phenyl-4H-benzo[g]chromene derivatives has been achieved by the reaction of 2-hydroxynaphthalene-1,4-dione, cyanothioacetamide, and aromaticaldehyde in EtOH at room temperature catalyzed by ZnCl2. The structures of the products were characterized by infrared, 1H NMR, mass, and elemental analysis.
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Ardeshir Khazaei Maryam Kiani Borazjani Shahnaz Saednia Mohammad Kiani Borazjani Maryam Golbaghi 《合成通讯》2013,43(10):1544-1553
A highly efficient procedure for etherification and oxidation of aromatic alcohol is described using unsupported and supported P2O5 on alumina and/or silica gel. The silica gel and alumina proved to be the most suitable support among the supports examined in our experiments. It was illustrated that the etherification and oxidative performance in reactions depend largely upon variables including reaction temperature, the nature of the P2O5 used (supported or unsupported P2O5), and whether solvent-free conditions are applied. It was shown that P2O5 not only can convert the aromatic alcohols into corresponding ethers and/or aldehyde and ketone but also can convert aromatic ethers into aldehyde or ketone via oxidative cleavage. Finally, quantum mechanical calculations were performed to rationalized these events, and it was indicated that aldehyde and ketone are more favorable products on the basis of the heat of formation (ΔHf).
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An efficient and environmentally benign method for the synthesis of organic carbamates was developed. Amines, CO2, and alkyl halides underwent a three-component reaction with the aid of K2CO3 and polyethylene glycol (PEG, MW = 400), affording the organic carbamates under ambient conditions. PEG could presumably act as a solvent and phase-transfer catalyst (PTC). Notably, the presence of PEG could also depress the alkylation of both the amine and the carbamate, thus resulting in enhanced selectivity toward the target carbamate. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file. 相似文献
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Abstract A simple and efficient method for multicomponant synthesis of 3,4-dihydropyrimidinones has been reported. All the reactions were carried out using samarium triflate as catalyst (10 mol%) at acetonitrile reflux. This procedure is applicable to a variety of substrates such as aliphatic, aromatic, and heterocyclic aldehydes.