共查询到20条相似文献,搜索用时 62 毫秒
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N-Boc-氨基噻吩的相转移催化N-烷基化;N-Boc-氨基;噻吩;N-烷基化;相转移催化 相似文献
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新型相转移催化剂的合成及其催化水解反应研究 总被引:2,自引:0,他引:2
相转移催化(PTC)技术是70年代初发展起来的应用在有机合成中的新技术。由于相转移催化剂能使反应速度加快,产率明显提高,反反化学通报1,2年第,期此,近年来相转移催化这一技术发展很快。高分子相转移催化剂,由于它具有在反应完毕后容易分离 相似文献
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使用两种 ω-氯代酰氯 (氯乙酰氯与氯丁酰氯) 对交联聚苯乙烯微球 (CPS) 进行 Friedel-Crafts 酰基化反应,使用 1,4-二氯甲氧基丁烷对 CPS 微球进行氯甲基化反应, 分别将可交换的氯引入 CPS 微球表面, 制备了化学改性的 CPS 微球. 然后使用三苯基膦对改性微球进行季鏻化反应, 制备了间隔臂 (spacer arm) 长度不同的三种季鏻 (QP) 盐型三相相转移催化剂 QP-CPS. 考察了主要反应条件对制备过程的影响, 并以氯化苄与乙酸钠合成乙酸苄酯的反应体系作为三相相转移催化的模型体系, 初步考察了 QP-CPS 的相转移催化活性,探索了催化剂结构与相转移催化活性的关系. 结果表明, 季鏻盐的化学稳定性较差,在制备过程中需控制反应时间与温度, 且宜选用极性较高的溶剂. 季鏻盐型三相相转移催化剂 QP-CPS 对乙酸苄酯的合成具有较高的催化活性, 在液-固-液之间可有效地实现反应物种乙酸根的转移. 与季铵盐 (QN) 型三相相转移催化剂 QN-CPS 相比, 季鏻盐型三相相转移催化剂 QP-CPS 具有更高的相转移催化活性. 间隔臂越长, QP-CPS 的相转移催化活性越高, QP-CPS 的亲水和亲油性能对相转移催化活性也有很大的影响. 相似文献
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杂多阴离子的相转移化学(Ⅳ):杂多阴离子与NO的配位反应 总被引:3,自引:1,他引:2
杂多阴离子的相转移化学(Ⅳ)──杂多阴离子与NO的配位反应王恩波,刘霞,王作屏,许林,高丽娟(东北师范大学化学系,长春,130024)关键词杂多阴离子,相转移,NO配位Pope等[1]发现表面含有配位水分子的杂多阴离子可以在相转移作用下转移到非极性溶... 相似文献
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用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
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Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
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《Tetrahedron》2014,70(21):3377-3384
The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative. 相似文献
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Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner. 相似文献