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A simple, rapid and efficient method for the synthesis of dibenzyl diselenides under microwave irradiation is reported. The effect of microwave irradiation power, times and solvent on the reaction is investigated. 相似文献
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We present here a general and easy method for the synthesis of several 2-aryl-1,3-benzoselenazoles from the reaction of bis(2-aminophenyl) diselenides with different aryl aldehydes, promoted by the non-toxic inorganic reducing agent sodium metabisulfite (Na2S2O5) in DMSO at 120 °C. This efficient method furnishes in high yields the corresponding 2-aryl substituted 1,3-benzoselenazoles and tolerates a range of substituents at the aryl ring of aldehydes. The use of focused microwave irradiation decreases drastically the reaction time from 48 to 2 h. 相似文献
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发展了一种微波-超声复合场下绿色高效合成砜类化合物的简便方法。 以芳甲基氯和苯亚磺酸钠为原料,以水为反应介质,在微波-超声复合场辅助下合成了一系列芳甲基苯基砜。 通过考察微波功率、超声功率、原料投料比、溶剂体积和反应时间等因素的影响,得出了苄基氯与苯亚磺酸钠之间模型反应的最优反应条件:微波功率为40 W,超声功率为50 W,苄基氯与苯亚磺酸钠的摩尔配比为1:3,反应时间为5 min。 在此条件下合成的苄基苯基砜产率为83%。 相比常规油浴条件,在微波-超声复合场的强化下反应速率提升了约42倍。 该方法具有较好的底物适应性,成功合成了23种砜类化合物。 相似文献
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研究了在水溶液体系中用微波加热使壳聚糖发生羧甲基化改性的反应。探讨了碱化时间、微波加热时间、投料比对反应产率的影响。确定了壳聚糖在水溶液中改性的最佳条件:壳聚糖∶NaOH∶一氯乙酸=1∶10∶8(质量比),碱化时间为2.5h,微波加热时间和温度分别为20min和100℃。 相似文献
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An efficient one-pot method has been developed for the synthesis of 1,2,4-oxadiazoles through a one-pot reaction of nitriles with hydroxylamine hydrochloride in the presence of magnesia-supported sodium carbonate followed by reaction with acyl halides under solvent-free conditions using microwave irradiation. This method is easy, rapid and good yielding. 相似文献
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An improved approach to the synthesis of organic diselenides is reported. The process involves the reaction of organic halides with selenium, carbon monoxide, and water under atmospheric pressure in the presence of an inorganic base, sodium hydroxide, to afford organic diselenides in good yields. 相似文献
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Under iodine-catalyzed and visible light-irradiated aerobic conditions, selenoalkoxylation of olefins with diselenides and alcohols can be efficiently achieved to afford the useful α-alkoxyl selenides in the presence of only 0.5 equiv. of H2O2. Controlling the sub-stoichiometric H2O2 amount is crucial to avoid the non-selective over-oxidation of the diselenides that leads to the ineffective hyper-valent selenium compounds. Meanwhile, under visible light irradiation, the green, safe, and low-cost air can work as a supplemental mild oxidant in the reaction to ensure selective oxidation of the diselenides, full conversion of the reactants, and ultimately good yield of the products. 相似文献
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Mizuki Yamada Mio Matsumura Erina Sakaki Shih-yun Yen Masatoshi Kawahata Tadashi Hyodo Kentaro Yamaguchi Yuki Murata Shuji Yasuike 《Tetrahedron》2019,75(10):1406-1414
A simple method for the synthesis of monoselenides and diselenides having 1,2,3-triazole ring is described herein. The three component reaction of ethynylstibanes, organic azides, and selenium powder is catalyzed by CuI (10?mol%) using 1,10-phenanthroline as the ligand (10?mol%) under aerobic conditions. Either selenides or diselenides can be synthesized by selecting the appropriate amount of selenium powder for otherwise identical reaction conditions. The obtained selenides and diselenides having a 1,2,3-triazole ring are all novel compounds. By using an antimony reagent, this one-pot reaction provides regioselective double Se-arylation under simple reaction conditions. 相似文献
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一种合成二硒化钠和有机二硒化物的新方法 总被引:5,自引:0,他引:5
二硒化物是有机合成中重要的原料及中间体,有些二硒化物还具有生物活性或催化活性。现已有多种方法合成二硒化物,其中用碱金属二硒化物与卤代烷发生取代反应制备二硒化物是较为直接的方法。二硒化钠(Na2Se2)是一种常用的二硒阴离子试剂,它可通过多种方法制得,由Klayman报道的在质子性溶剂、中性条件下用硼氢化钠(NaBH4)还原硒粉(Se)的方法,由于其简便易行常被采用。我们在用此法制备二硒化物时,发现在碱性条件下,反应以一种新的方式进行,相对于Klayman方法具有很多优点,现报道如下。 相似文献
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A novel application of microwave irradiation for the epoxidation of some simple alkenes, in which hydrogen peroxide was used as an oxidant together with sodium tungsten and phosphorous acid under phase‐transfer catalytic (PTC) conditions, is described as a new environmentally benign method. In comparison with conventional heating, the microwave process is a very useful alternative for introducing of the oxirane ring into some unsaturated hydrocarbons because of reduction of the reaction time and increase in yield. 相似文献
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Nuriye Kocak Mustafa Sahin Ilker Akin Mahmut Kus Mustafa Yilmaz 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10):776-779
Chitosan nanoparticles (CHN) were prepared based on ionotropic gelation between low moleculer weight chitosan and sodium tripolyphosphate (TPP) under microwave irradiation. Particle size, zeta potential, and FT-IR techniques were used for characterization of CHN. The influence of reaction time on the nanoparticle size distribution was investigated, and the results showed that the microwave irradiation method evidently decreases the reaction times and particle size over the conventional method. It was determined by the results of the zeta potential measurements that synthesized CHN under microwave irradiation clearly exhibits more homogeneous and stable dispersion. 相似文献
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Sandeep Vasantrao Rohokale Santosh Rajaram Kote Santosh Rangnath Deshmukh Shankar Ramchandra Thopate 《Chemical Papers》2014,68(4):575-578
Naturally occurring organic acids are reported to be highly efficient promoters of the Beckmann rearrangement. Citric, oxalic, tartaric, malic, succinic, malonic, and fumaric acids efficiently promote the Beckmann rearrangement under solvent-free conditions and thermal and microwave irradiation. Tartaric acid was found to be the best promoter of the Beckmann rearrangement under conventional conditions as well as under microwave irradiation. Compared with conventional heating, microwave irradiation provides higher reaction rate and slightly higher yields. 相似文献
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An experimentally simple sequential one-pot RuAAC reaction, affording 1,5-disubstituted 1H-1,2,3-triazoles in good to excellent yields starting from an alkyl halide, sodium azide, and an alkyne, is reported. The organic azide is formed in situ by treating the primary alkyl halide with sodium azide in DMA under microwave heating. Subsequent addition of [RuClCp*(PPh(3))(2)] and the alkyne yielded the desired cycloaddition product after further microwave irradiation. 相似文献
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<正>A facile and efficient method for the preparation of 2-non-substituted quinoline-4-carboxylic acids is described via the Pfitzinger reaction of isatins with sodium pyruvate following consequent decarboxylation under microwave irradiation. 相似文献
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A general and efficient synthetic method of 1-phenoxy-3-arylseleno-2-propanol by reducing diary1 diselenides with sodium borohydride in basic environment and their reaction with epoxypropoxyphenols are described. 相似文献
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Various diselenides assist in the sulfuration of dienes giving cyclic di- and tetrasulfides as main products. The reaction requires a 2-fold excess of diselenides to be efficient. Catalytic amounts of diselenides result in lower yields. This is likely due to secondary reactions (polymerization, aromatization) occurring during extended reaction times under catalytic conditions. It was verified that the sulfur-transferring properties of diselenatetrasulfides are virtually identical to those of diselenides combined with sulfur. Contrary to previous claims, not only the cyclic diselenatetrasulfide but also linear diselenatetrasulfides (RSeSnSeR) transfer sulfur to dienes. A mechanism is proposed and its implications to the nature of diatomic sulfur are discussed. 相似文献