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在SmI_2-HMPA-THF-t-BuOH体系中,硫代碳酸酯的酰硫键发生还原断裂反应,得到相应的二硫醚产物。 相似文献
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室温下SmI2-THF-HMPA-t-BuOH体系可顺利地将二硫代氨基甲酸酯还原断裂得到二硫醚和硫代甲酰胺; 同样条件下, 硫代氨基甲酸酯还原断裂得到二硫醚篅34The reductive cleavage of dithiocarbamic esters are promoted by the SmI2-HMPA-THF-t-BuOH System successfully to give disulfides and thiocarboxamides at room temperature in good yields; The reduction of thiocarbamic esters are also promoted by the same system to give disulfides and carboxamides. 相似文献
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二碘化钐作为易得的路易斯酸型预催化剂,可有效催化芳胺和碳二亚胺的反应,在温和条件下以高收率得到一系列胍。 相似文献
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偕二氟烯烃是一类重要的含氟有机化合物,在有机合成化学和药物化学研究领域展现出独特的结构优势.例如,偕二氟烯基可以便利地转化为单氟烯基、二氟烷基、三氟甲基以及其他多种含氟结构.偕二氟烯基结构作为羰基理想的电子等排体在药物设计研究中也有广泛的应用.报道了一种镍促进的电化学还原交叉偶联反应合成功能化的偕二氟烯烃.该反应在非分隔电解槽中进行,在温和的电化学还原条件下,实现了三氟甲基烯烃烯丙基脱氟、氧化还原活性羧酸酯脱羧或者烷基卤化物脱卤素的有机结合.反应可有效避免使用化学计量的金属粉末或有机还原剂.该反应为含偕二氟烯基功能结构的生物活性分子提供了有效的合成途径. 相似文献
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Samarium diiodide (SmI2) was found to be an efficient catalyst for the condensation of o-phenylenediamine and ketones to afford the corresponding 2,3-dihydro-1H-benzo[b][1,4]-diazepines in moderate to excellent yields under very mild and solvent-free conditions. The real active species here was suggested to be a Sin(Ⅲ) intermediate formed in situ and the mechanism of the present reaction was proposed. 相似文献
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Group 14 element catenates such as di-, tri-, poly-germanes, and polystannanes are efficiently synthesized by use of the one-electron reducing agent SmI2 under mild homogeneous conditions in good yields. 相似文献
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The amide bond between an amino acid and proline can take the trans- or cis-conformation. The conformation influences both the structure and function of peptides and proteins. Therefore, constrained mimetic, which corresponds to Pro-dipeptides whose amide bond is replaced with an (E)- or (Z)-alkene, is a useful bioprobe for elucidating the structure-function relationship of peptides and proteins. Herein, we report the synthesis of cis-(Z)-alkene-containing Pro-dipeptide mimetics via a samarium(II) diiodide (SmI2)-mediated reductive alkylation reaction. 相似文献
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Samarium(II) diiodide mediated intramolecular cyclisation of mixed enone-enoate substrates in THF/MeOH is described. Spirocyclic ethers are obtained, and the stereodefined preparation of 1-oxaspiro[4.4]nonan-7-one products is included. 相似文献
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Samarium(II)-induced coupling of acid chlorides with allylic halides gave diallylated tertiary alcohols. Monoallylated allylic ketones could not be obtained. 相似文献
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Bis(cyclopentadienyl)samarium(II) has been shown to be insoluble in thf : ether mixtures, hence it cannot be isolated as a soluble product from the reaction of samarium with HgCp2 in thf : ether. 相似文献
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《合成通讯》2013,43(7):1095-1101
Abstract The intermolecular reductive coupling of 1,1-diaryl-2,2-dicyanoethylenes or 1,1-diaryl-2-cyano-2-ethoxycarbonylethylenes with substituted benzalazines induced by samarium diiodide was studied. Functionalized 2,3-dihydropyrroles were prepared in good yields under neutral and mild conditions. 相似文献
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Xiaoxia WangYongmin Zhang 《Tetrahedron》2003,59(23):4201-4207
N-Acylbenzotriazoles, when treated with samarium diiodide in THF, undergo self-coupling reaction to afford 1,2-diketones in good to excellent yields; while when treated with samarium diiodide in CH3CN, they undergo ring-opening reaction to afford 1-acylamido-2-alkyl (or aryl) benzimidazoles in reasonable to good yields. A plausible mechanism was suggested. 相似文献
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The reaction of samarium(II) diiodide with in situ prepared disodium‐1,1,3,3‐tetraphenyl‐1,3‐disiloxanediolate, [(Ph2SiONa)2O], afforded the unusual heterobimetallic samarium(III) disiloxanediolate cluster [Me3SiO{μ‐Na(THF)}3Sm{μ‐(Ph2SiO)2O}3Na(THF)] ( 1 ) in low yield. A single‐crystal X‐ray structure determination of 1 revealed the presence of a polycylic inorganic ring system in which the samarium atom is not only chelated by three [(Ph2SiO)2O]2? ligands but is also part of a SmNa3O4 heterocubane cage. 相似文献
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Summary. We report a new reductive fragmentation/aldol tandem reaction in a 1,4-diketone induced by samarium(II) iodide. Due to the
particular stereoelectronic situation in the molecule, an alternative pathway was avoided despite the fact that it would have
greatly reduced the strain in the tricyclic molecule.
Received February 23, 2001. Accepted March 7, 2001 相似文献
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Myeongseob Kim Brian W. Knettle Anders Dahln Gran Hilmersson Robert A. Flowers II 《Tetrahedron》2003,59(52):10397-10402
The reductive coupling of aldimines and ketimines by a series of Sm(II)-based reagents (SmI2, SmI2–HMPA, SmBr2, Sm{N[Si(CH3)3]2}2, and SmI2/triethylamine/water) were examined. In general, aldimines and ketimines were efficiently reduced or coupled using reductants that are more powerful than SmI2, and the use of Sm{N[Si(CH3)3]2}2 led to higher diastereoselectivities in reductive coupling reactions. Surprisingly, only the combination of SmI2/triethylamine/water was capable of reducing and coupling para-substituted benzaldimines and coupling ketimines. 相似文献