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In this report, we try to show the importance of incorporation of name reactions in the sequential cascade reaction in which significantly decreasing the number of steps towards an ideal and practical multi-step synthesis of natural products as well showing virtually all the advantages already mentioned for “Click Chemistry”. In addition, since the chiral inductions are desired for most of these sequential name reactions, their asymmetric catalyzed reactions were also described. 相似文献
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《Green Chemistry Letters and Reviews》2013,6(4):311-320
Abstract In the second part of our paper, further recent developments of ionic liquids in selected name reactions of carbonyl chemistry such as Mannich, Reformatsky, Cannizaro, Streacker, Barbier, Pechmann, etc. are described. 相似文献
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Thermal reaction of 2-[N-(alk-2-enyl)benzylamino]-3-(2-substituted and 2,2-disubstituted)vinylpyrido[1,2-a]pyrimidin-4(4H)-ones gave azepine, the desired ene products, and/or pyran derivatives. The formation of the latter was responsible for the [4+2] cycloaddition reaction between the α,β-unsaturated ester carbonyl moiety as a diene part and the alkenylamino moiety as an ene one. The reaction features depended upon the kinds of substituents both on the vinyl and alkenyl counterparts; strongly electron-withdrawing substituents on the vinyl moiety or an electron-donating substituent on the alkenyl one changed the reaction feature from the ene reaction to the hetero Diels-Alder reaction. 相似文献
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温度和时间对有机合成反应影响的探讨 总被引:1,自引:0,他引:1
根据物理化学和有机合成原理,从动力学、热力学、反应机理及溶解度等各方面详细分析了反应温度和反应时间对有机合成反应的影响。通过这些分析,可以让同学们更好地在合成反应课程的学习中掌握和分析反应温度和反应时间对反应的影响。 相似文献
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Thomas A. Klein 《Tetrahedron letters》2005,46(27):4535-4538
Dimethylnitro alcohols are constructed in a one-pot process from benzylic halides and 2-nitropropane. The use of tetrabutylammonium fluoride (TBAF) as the promoter is essential for this tandem Hass-Bender/Henry reaction to proceed. 相似文献
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Yoshishige Okuno 《International journal of quantum chemistry》2000,77(4):791-796
A microscopic method to examine a nonequilibrium solvation effect is reported. The solution reaction is simplified as a barrier‐crossing reaction within a solution reaction surface that corresponds to a two‐dimensional space determined by solute and solvent reactive coordinates. For this simplification, the motions within the space spanned by nonreactive coordinates are frozen. We derive three rate constant expressions: (1) in the nonadiabatic solvation limit, (2) in the equilibrium solvation limit, and (3) of the transition‐state theory. This method was applied to the examination of the contact‐ion‐pair formation of t‐BuCl in four waters. We found that the nonadiabatic solvation picture overestimates the nonequilibrium solvation effect. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 77: 791–796, 2000 相似文献
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钯催化的交叉偶联反应是非常实用的合成新方法.文章给出了Heck反应、Negishi反应和Suzuki反应的概念,对其反应机理作了详细的说明,并对其在复杂化合物和天然产物全合成中的应用作了评价. 相似文献
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An efficient and straightforward synthesis of beraprost sodium was developed with dicyclopentadiene as a starting material, a one-pot reaction product 5 as key intermediate and the Prins reaction and the Horner-Wads- worth-Emmons reaction as key steps. The structures of the key intermediate and the target compound were confirmed by 1H NMR, 13C NMR and MS. The purity of beraprost sodium identified by high performance liquid chromatography(HPLC) was identical to that of Japanese Pharmacopoeia(16th). This development will be used for the industrial synthesis of beraprost sodium. 相似文献
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杂环化合物广泛存在于天然产物和药物分子中,许多杂环化合物还具有潜在生物活性和药理作用。因此,如何快速高效地构建小分子杂环化合物库成为当今有机合成和药物化学领域的研究热点。Ugi反应在多样性导向合成方面具有得天独厚的优势,能够解决待合成化合物数量庞大、结构复杂的难题;同时,Diels-Alder [4+2]环加成反应能够高效构建碳-碳键,以较高的立体选择性和区域选择性合成六元环系。目前,集二者于一身的Ugi/Diels-Alder串联反应在构建杂环化合物方面展现出了巨大优势和无穷潜能。本文以不同类型的DA反应分类:按照呋喃作为双烯体、吡咯作为双烯体、噻吩为双烯体、口恶唑作为双烯体、 1,2,4-三嗪作为双烯体、苯作为双烯体、不饱和键和芳环共同作为双烯体等对UDA串联反应的研究进行了综述。 相似文献
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Jaime Baeza Juanita Freer Graciela Palma 《Monatshefte für Chemie / Chemical Monthly》1984,115(11):1369-1371
The oxidative addition of benzenethiol to indene in the presence of ovoalbumin produces only one isomer on the surface of the protein,trans-anti-2-phenylsulfinyl-1-indanol. This reaction may be considered as a biomimetic model of detoxification of certain hydrocarbons by the liver.
Stereoselektive oxydative Anlagerung von Thiophenol an Inden in Gegenwart von Ovoalbumin (Kurze Mitteilung)
Zusammenfassung Durch die oxydative Anlagerung von Thiophenol an Inden in Gegenwart von Ovoalbumin bildet sich nur ein Isomer an der Oberfläche des Proteins, dastrans-anti-2-Phenylsulfinyl-1-Indanol. Diese Reaktion kann als ein biomimetisches Modell der Entgiftung von gewissen Kohlenwasserstoffen durch die Leber betrachtet werden.相似文献
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The old classification of basic chemical reactions was evaluated and a new systematic classification of basic reactions was proposed.In the new classification,all the chemical reactions were divided into oxidation-reduction reactions and non-oxidation-reduction reactions,and both can be divided into combination reaction,decomposition reaction and replacement reaction,respectively.In addition,a new class of basic reactions,the complicated decomposition reaction,was appended to reaction system. 相似文献
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Irina-Claudia Grig-Alexa Adriana-Luminita Finaru Lucia Ivan Paul Caubère 《Tetrahedron letters》2004,45(11):2343-2346
Various 4-substituted dihydrodipyridopyrazines were synthesized by palladium-mediated cross-coupling reactions. Starting from the corresponding 4-iodo or 4-bromo derivatives, the incorporation of aryl, vinyl, alkynyl and methoxycarbonyl groups is described. 相似文献
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《Mendeleev Communications》2021,31(6):769-780
The synthesis of the desired chemical compound is the main task of synthetic organic chemistry. The predictions of reaction conditions and some important quantitative characteristics of chemical reactions as yield and reaction rate can substantially help in the development of optimal synthetic routes and assessment of synthesis cost. Theoretical assessment of these parameters can be performed with the help of modern machine-learning approaches, which use available experimental data to develop predictive models called quantitative or qualitative structure–reactivity relationship (QSRR) modelling. In the article, we review the state-of-the-art in the QSRR area and give our opinion on emerging trends in this field. 相似文献
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The Stille coupling of organostannanes and organohalides, mediated by air and moisture stable palladium(II) phosphine complexes containing succinimide or phthalimide (imidate) ligands, has been investigated. An efficient synthetic route to several palladium(II) complexes containing succinimide and phthalimide ligands, has been developed. cis-Bromobis(triphenylphosphine)(N-succinimide)palladium(II) [(Ph3P)2Pd(N-Succ)Br] is shown to mediate the Stille coupling of allylic and benzylic halides with alkenyl, aryl and allyl stannanes. In competition experiments between 4-nitrobromobenzene and benzyl bromide with a cis-stannylvinyl ester, (Ph3P)2Pd(N-Succ)Br preferentially cross-couples benzyl bromide, whereas with other commonly employed precatalysts 4-nitrobromobenzene undergoes preferential cross-coupling. Furthermore, preferential reaction of deactivated benzyl bromides over activated benzyl bromides is observed for the first time. The type of halide and presence of a succinimide ligand are essential for effective Stille coupling. The type of phosphine ligand is also shown to alter the catalytic activity of palladium(II) succinimide complexes. 相似文献
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Electrocatalysts are the cores of many electrochemical reactions including hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), nitrogen reduction reaction (NRR), and CO2 reduction reaction (CO2RR). Recent advances in research have demonstrated the potentials of molybdenum carbide-based catalysts for these reactions arising out of their unique electronic structure and physicochemical properties. In this review, we systematically summarize the recent advances of molybdenum carbide-based catalysts in these electrochemical processes. The corresponding synthesis strategies, structure and electrocatalytic performance of the catalysts are discussed and the relationships of the process-structure-property are highlighted. In addition, the catalytic mechanisms are analyzed based on the structure characterization and theoretical calculations results. Finally, the existing challenges and future perspectives are put forward for further development of molybdenum carbide-based catalysts. 相似文献