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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.
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   

4.
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   

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.
合成了3个三环己基锡-2-(1,2-亚乙二硫)亚甲基-3-羰基-5-芳基-4-戊烯酸酯化合物。用IR,^1H NMR,^13C NMR^119Sn NMR光谱及X射线衍射对所合成的化合物进行了表征,结果表明标明化合物为四配位、具有畸变四面体结构的锡酯类化合物。  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.
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   

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.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

14.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

15.
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   

16.
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   

17.
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   

18.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

19.
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.  相似文献   

20.
In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.  相似文献   

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