共查询到20条相似文献,搜索用时 93 毫秒
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氰基化合物不仅广泛存在于医药和农药分子中,还是一类重要的中间体.传统合成氰基化合物的方法是使用氰化钠、氰化钾和氢氰酸等最简单的氰化试剂,但这类氰化试剂的剧毒性和不稳定性限制了其在合成中的应用.因此发展有机氰化试剂和无氰源试剂构建氰基化合物的策略备受关注.氮杂环卡宾是一类高效的有机小分子催化剂,可用于实现多种碳-碳(C—C)和碳-杂(C—X)键的形成.综述了氮杂环卡宾催化有机氰化试剂和无氰源试剂构建氰基化合物的反应,目的是引起更多的化学工作者关注该领域的发展,并提供氮杂环卡宾催化活化模式的新思路. 相似文献
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研究了亲核试剂对IB 1 ,3 二 (2 氯异丙基 )苯 (DiCumCl) TiCl4体系正离子聚合反应的规律 ,亲核试剂与增长的碳正离子作用的紫外光谱图 ;采用分子模拟 ,利用量子力学半经验方法计算了亲核试剂与质子反应的活化能 ,确定了不同亲核试剂与质子的作用能力 ;利用分子力学方法计算了在增长碳正离子末端的不同位置亲核试剂与之络合的稳定化能 ,根据能量最低原则确定了亲核试剂在碳正离子链端的作用位置 ;利用分子力学方法进行构象优化后 ,借助QEq方法得到了聚异丁烯碳正离子和聚苯乙烯碳正离子的电荷数值 .综合以上实验结果提出了亲核试剂在正离子聚合反应中的作用及其作用机理 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(33):10023-10028
Layered black phosphorus has been attracting great attention due to its interesting material properties which lead to a plethora of proposed applications. Several approaches are demonstrated here for covalent chemical modifications of layered black phosphorus in order to form P−C and P‐O‐C bonds. Nucleophilic reagents are highly effective for chemical modification of black phosphorus. Further derivatization approaches investigated were based on radical reactions. These reagents are not as effective as nucleophilic reagents for the surface covalent modification of black phosphorus. The influence of covalent modification on the electronic structure of black phosphorus was investigated using ab initio calculations. Covalent modification exerts a strong effect on the electronic structure including the change of band‐gap width and spin polarization. 相似文献
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Dipl.‐Chem. Alexander Schwenger Dr. Wolfgang Frey Prof. Clemens Richert 《Angewandte Chemie (International ed. in English)》2016,55(44):13706-13709
Tetrakis(dimethoxyphenyl)adamantane (TDA) readily forms crystalline inclusion complexes with reactive, toxic, or malodorous reagents, such as benzoyl chloride, acetyl chloride, cyclohexyl isocyanide, phosphorus trichloride, and trimethylsilyl chloride. The crystals are stable and largely free of the problematic properties of the free reagents. When exposed to solvents such as DMSO or MeOH, the reagents react, and a large portion of the TDA precipitates. The TDA‐coated reagents may lead to a safer way of storing, handling, and delivering reagents, and ultimately to synthetic protocols that do not require fume hoods. 相似文献
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The spectral interferences of phosphorus species originating from the thermal decomposition of calcium phosphate on Sb, As, Se and Te resonance lines, and the influence of increasing amounts of Ce, Ni, W, Pd, Pt, Zr and other elements on non-correctable signals generated by calcium phosphate and on selenium and phosphorus sensitivity have been studied. The results indicate that spectral interference is caused by P2 absorption and that the extent of interference depends on the wavelength and the spectral band width. The generation of P2 is masked by large amounts of all the tested reagents. There is a significant reduction in selenium sensitivity in the presence of high concentrations of Ce, Pd and Pt while no decrease in sensitivity is caused by the presence of even 1% nickel and tungsten solutions. All the reagents tested provided enhanced phosphorus sensitivity, thorium being the best. 相似文献
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Somaia M. Abdel‐kariem 《Journal of heterocyclic chemistry》2019,56(7):1922-1927
Synthesis of some novel organophosphorus compounds bearing 1,2,4‐triazinone moiety was achieved. The methodology depended on simple reactions between 4‐amino‐6‐methyl‐3‐sulfanyl‐1,2,4‐triazin‐5(4H)‐one ( 1 ) and variable phosphorus reagents such as phosphorus halides and phosphorus sulfides as well as phosphorous acid and its esters. These reactions were performed in proper solvents under mild conditions giving good yields of phosphorylated 1,2,4‐triazinones. 相似文献
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Dr. Valentín Hornillos Dr. Manuel Pérez Dr. Martín Fañanás‐Mastral Prof. Dr. Ben L. Feringa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(17):5432-5441
An efficient and highly enantioselective copper‐catalyzed allylic alkylation of phosphonates and phosphine oxides with Grignard reagents and Taniaphos or phosphoramidites as chiral ligands is reported. Transformation of these products leads to a variety of new phosphorus‐containing chiral intermediates. 相似文献
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Lucie Appy Anaïs Depaix Xavier Bantreil Frédéric Lamaty Suzanne Peyrottes 《Phosphorus, sulfur, and silicon and the related elements》2020,195(11):930-931
AbstractWe have developed original one-pot and protecting group-free approaches, which are also user-friendly and reliable, to synthesize nucleotides and derivatives starting from nucleoside 5’-monophosphates. Both methods present convenient set-up, i.e., non-dry solvents and reagents, substrates in their sodium or acid form, and commercially available and cheap phosphorus reagents as sodium and potassium salts. 相似文献
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I. V. Shevchenko M. V. Furmanova V. P. Kukhar O. I. Kolodiazhnyi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract We found the title compound 1 to contain a very labile P-C bond, which is readily cleaved under the action of protondonating reagents, even as weak as aniline, and other electropnilic reagents as well as under the conditions of sulphuration or imination. This can probably be explained by the presence of bulky substitutes at phosphorus and the ability of bis(dimethylamino)methyl group to form the thermodynamically stable formamidinium cation (1). 相似文献
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2-Bromo-3,4-dicyanopyridine 2 was obtained in moderate yield by reacting 1,1,2,2-tetracyano-3-trimethylsiloxycyclobutane 1 with phosphorus tribromide. Similarly, reaction of 1 with chlorinating reagents such as thionyl chloride and oxalyl chloride led to the corresponding 2-chloro-3,4-dicyanopyridine 3 in 40% yield. A reaction mechanism is suggested. 相似文献
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A new synthetic approach to aromatic diols substituted with two, three, and four (similar or different) phosphorus groups via the Michael‐type addition of the P H bond containing reagents to p‑benzoquinone derivatives, reoxidation, and subsequent addition of another phosphorus unit is presented. A variety of new phosphorus‐containing p‑hydroquinone derivatives were synthesized and fully characterized. 相似文献
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Yu. G. Trishin V. N. Chistokletov A. A. Petrov 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract A general method of phosphorus heterocycle synthesis has been developed. It is based on the interaction between α,β-ethylene, acetylene P(III) derivatives and reagents, which contain electrophilic and nucleophilic centres in α,β- and α,β-positions, e.g. compounds with activated multiple bonds; β-halogenalcanols and thiols; nitrilimines, nitrilylides as 1,3-dipoles. This process is an unsynchron-ic ionic cycloaddition which begins with the attack of a phosphorus atom to the electrophilic centre of a reagent. 相似文献