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1.
张蓉  赵邦蓉 《合成化学》2003,11(1):76-79
利用β-环糊精的吡喃葡萄糖单元上2,3,6-位羟基氢的反应活性差异,选用合适的催化剂和修饰剂合成了十四,(2,6-O-烯丙基)-β-环糊精,研究了反应温度,反应时间、催化剂、修饰剂等对合成的影响,产物经元素分析,IR,1H,NMR,FAB-MS等表征。  相似文献   

2.
SAPO—11分子筛用i—Pr2NH导向合成及其酸性研究   总被引:3,自引:0,他引:3  
以AlPO4、H3PO4、SiO2等为原料采用单一模板剂iPr2NH合成了SAPO11分子筛,利用Avrami方程等对合成过程进行了定量描述。还利用红外(IR)、程序升温脱附(TPD)、线性丁烯骨架异构反应催化活性测试等手段表征了SAPO11的酸性。结果表明,合成过程随温度有明显变化,晶化阶段的活化能远高于核化阶段的值。可用Avrami方程的参数来表征合成过程的难易程度。分子筛中存在B酸和L酸位,主要在中等强度范围,从而对线性丁烯骨架异构反应有较好的催化活性。提高分子筛中硅含量可明显增大酸位浓度,酸强度也有轻度增强。  相似文献   

3.
张蓉  赵邦蓉 《合成化学》2003,11(2):178-180
利用氢氧化钠作催化剂使β-环糊精(简称β-CD)被烯丙基修饰合成了七-(2,3,6-O-烯丙基)-β-环糊精[Heptakis-(2,3,6-O-allyl)-β-CD]。用正交实验法考察了反应温度、反应时间、催化剂用量和修饰剂-烯丙基溴用量等因素对合成目标化合物的影响,得出合成七-(2,3,6-O烯丙基)-β-环糊精的最佳实验条件:n(β-环糊精):n(烯丙基溴)=1:86.92,n(催化剂):n(烯丙基溴)=1:1.052。产物经元素分析,IR和1HNMR表征和确认。  相似文献   

4.
在Na_2O-1.6-C_6H_(14)N_2-SiO_2-TiO_2-H_2O体系中首次用快速动态法和静态法合成了TiZSM-48型分子筛,考察了两种合成方法的晶化动力学。利用XRD、IR、XPS、SEM、DRS、TG-DTA等测试手段对TiZSM-48型分子筛进行了表征,结果表明,Ti进入了分子筛骨架,动态法合成比静态法合成快得多,且样品的晶粒较小。热分析表明,两种方法合成的样品热稳定性均较好。  相似文献   

5.
由氯甲基聚苯乙烯和多-1,2-亚乙基多胺反应合成了聚苯乙烯我-1,2-亚乙基多胺树脂,并通过质量变化,分析,交换量和红外光谱进行了表征,研究了利用该树脂催化合成正丁基苯基醚的反应,催化剂能够回收并重复使用,4次后其质量未损失,活性未下降。  相似文献   

6.
利用P(NEt2)3与双酰胺类化合物在干馏条件下的环缩合反应了一系列含双芳氧乙酰基的新型五元磷杂环,对所合成的化合物进行了元素分析和谱学表征。初步生物活性测定表明,部分化合物具有优良的选择性除草活性。合成中首次发现此类磷杂环的P=Se与P-Se的转化现象,通过X射线单晶衍射确定证了产物的结构,并发现产物分子间氢键的存在。  相似文献   

7.
MCM—48介孔分子筛的合成研究   总被引:14,自引:3,他引:11  
利用水热法合成了MCM-48介孔分子筛,通过IR,TG-DTA,XRD,XRD,TEM,N2吸附等方法对产物进行了表征,并系统地研究了晶化温度、晶化时间、凝胶组成等对合成MCM-48介孔分子筛的影响。  相似文献   

8.
β-PbO2纳米棒及Pb3O4纳米晶的制备与表征   总被引:7,自引:0,他引:7  
利用NaClO在碱性溶液中与Pb(Ac)2进行氧化反应直接合成出直径为10-20nm、长度为400nm、长径比达20以上的纯相β-PbO2纳米棒,对所得β-PbO2在420℃下进行热解,得到晶粒尺寸为20nm左右的Pb3O4。对液相氧化反应的温度、时间、氧化剂浓度、pH等因素的影响进行了详细研究,获得了最佳合成反应条件,所得产物利用粉末X射线衍射和透射电子显微镜分析进行了表征。  相似文献   

9.
稀土与8-羟基喹啉三元配合物的合成研究Ⅱ.甲基丙烯酸稀土与8-羟基喹啉三元固态配合物的合成与表征王学智(安徽机电学院食品工程系芜湖241000)关键词稀土甲基丙烯酸8-羟基喹啉三元配合物Biryulina[1]首次报导了甲基丙烯酸稀土的合成与表征。8...  相似文献   

10.
冯志强  尹承烈 《合成化学》2001,9(4):341-344
以L-谷氨酸为手性原料,经过环化、酯化、N-甲基化和格氏加成反应合成了11个(S)-α,α-二烃基-5-氧代-1-甲基-2吡咯烷甲醇,并进行了表征。  相似文献   

11.
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   

12.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

13.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
Zhanhui Yang  Shiyi Yang  Jiaxi Xu 《Tetrahedron》2017,73(23):3240-3248
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   

19.
A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.  相似文献   

20.
A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.  相似文献   

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