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71.
Batool Akhlaghinia 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):1783-1786
Tetrahydropyranyl ethers were converted to their corresponding alkyl cyanides efficiently by using the triphenylphosphine/ 2,3-dichloro-5,6-dicyanobenoquinone/n-Bu 4 NCN system in refluxing acetonitrile with good-to-excellent yields. 相似文献
72.
Boris I. Usachev Vyacheslav Ya. Sosnovskikh Mikhail A. Shafeev Gerd-Volker Röschenthaler 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5-6):1315-1319
Abstract Alkyl 2-mercaptophenyl ketones react with trifluoroacetic anhydride in the presence of triethylamine to give 2-(trifluoromethyl)-4H-thiochromen-4-ones, which are transformed into the corresponding pyrazoles by treatment with hydrazine hydrate and into 1,1-dioxides by oxidation with H2O2 in AcOH. 相似文献
73.
An efficient two‐step synthesis of 3,6‐diaminopyridazine from 3,6‐dichloropyridazine is reported. In this synthetic procedure, 4‐methoxybenzylamine was used as a nitrogen source to substitute the chloro groups of 3,6‐dichloropyridazine to form N,N′‐bis‐(4‐methoxybenzyl)‐pyridazine‐3,6‐diamine. The 4‐methoxybenzyl groups were then removed by treatment with hydrochloric acid to provide the target 3,6‐diaminopyridazine with an overall yield of 78%. 相似文献
74.
Naoyuki Masuda Osamu Yamamoto Masahiro Fujii Tetsuro Ohgami Ayako Moritomo Toru Kontani 《合成通讯》2013,43(17):2305-2316
Various N‐3‐alkylated thiazolidenesulfonamide derivatives were efficiently prepared by the direct endo‐selective alkylation of thiazolylsulfonamides. The effects of different bases and solvents were investigated, and the NaH–THF combination was found to be the most effective at conferring high yields and endo‐selectivity. 相似文献
75.
Mediated by samarium diiodide, 1-(benzotriazole-1-yl)alkyl esters 1 underwent cross-coupling with aldehydes or ketones to afford β-(benzotriazole-1-yl)alcohols 2 exclusively with the selective removal of acyloxy over benzotriazolyl. 相似文献
76.
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
77.
Torsten Kerber Rachel Nathaniel Kerber Xavier Rozanska Philippe Sautet Paul Fleurat‐Lessard 《Journal of computational chemistry》2013,34(13):1155-1163
We present a new software to easily perform QM:MM and QM:QM' calculations called QMX. It follows the subtraction scheme and it is implemented in the Atomic Simulation Environment (ASE). Special attention is paid to couple molecular calculations with periodic boundaries approaches. QMX inherits the flexibility and versatility of the ASE package: any combination of methods namely force field, semiempirical, first principle, and ab initio, can be used as hybrid potential energy surface (PES). Its ease of use is demonstrated by considering the adsorption of Al2Cl3Me3 on silica surface and by combining different levels of theory (from standard DFT to MP2 calculations) for the so‐called High Level cluster with standard PW91 density functional theory calculations for the Low Level environment. It is shown that the High Level cluster must contain the silanol group close to the aluminum atoms. The bridging adsorption is favored by 58 kJ mol?1 at the MP2:PW91 level with respect to the terminal position. Using large clusters at the MP2:PW91 level, it is shown that PW91 calculations are sufficient for structure optimization but that embedded methods are required for accurate energy profiles. © 2013 Wiley Periodicals, Inc. 相似文献
78.
A. De Kok M. Van Opstal T. De Jong B. Hoogcarspel R. B. Geerdink R. W. Frei 《International journal of environmental analytical chemistry》2013,93(1-2):101-123
Abstract In earlier work, various strategies have been developed for the trace-level determination of phenylurea herbicides and the anilines which are their main degradation products. They include catalytic hydrolysis of the phenylureas on silica, liquid chromatographic fractionation of complex mixtures of herbicides and anilines, derivatization of anilines and herbicides with electron-capture-sensitive reagents, and final analysis by means of capillary gas chromatography. In the present paper, the application of these principles to trace-level analysis of surface water, soil and crop samples is demonstrated. 相似文献
79.
Takumi Nakajima Ken Takano Hiromu Maeda Dr. Yohei Ogiwara Prof. Dr. Norio Sakai 《化学:亚洲杂志》2021,16(24):4103-4107
The results of this study show that disilathiane is an effective mediator in the synthesis of alkyl aryl sulfides with disulfides and alkyl carboxylates. Mechanistic studies suggest that disilathiane promotes cleavage of the sulfur–sulfur bond of disulfides to generate thiosilane as a key intermediate. Diselenides were also applicable to this transformation to produce the corresponding selenides. 相似文献
80.
研究了四种不同烷基链长度的对称季铵碱对草酸电还原制备乙醛酸反应的影响。线性扫描测试考察了添加剂对铅电极上阴极反应的影响,结果表明对称季铵碱在电极表面的吸附对析氢反应的抑制程度大于其对草酸电还原反应的抑制程度,且随着对称季铵碱中烷基链长度的增加,添加剂抑制析氢反应效果更明显。计时安培法的结果证明添加剂可影响草酸向电极表面的扩散,随着对称季铵碱中烷基链长度的增加,草酸的扩散系数呈现出先增加后减小的趋势。恒流电解实验结果表明,添加剂能有效提高草酸电还原反应的电流效率,且提高效果随对称季铵碱所含烷基链长度的增加而增强。因此,添加剂的吸附对阴极表面析氢反应的抑制作用是草酸电还原反应电流效率提高的主要原因。本研究表明,四丁基氢氧化铵为添加剂时,草酸还原为乙醛酸的电流效率最高。 相似文献