聚环氧磺羧酸的合成及其阻垢性能

聚环氧磺羧酸的合成及其阻垢性能;聚环氧磺羧酸; 聚环氧琥珀酸; 阻垢剂     

近化学计量比碳化硅的制备及其结构表征

近化学计量比碳化硅的制备及其结构表征;聚碳硅烷;聚甲基硅烷;聚环硼氮烷     

新型阳离子聚丙烯酰胺离解行为的研究

前文曾报导,以聚丙烯酰胺为母体,通过甲醛为桥梁引入二氰二胺可合成一种新型阳离子聚电解质,简称PAm·MG,它是一种弱聚碱的盐酸盐,结构式如下(S 为取代度):PAm·MG 对含活性艳红染料的废水有明显的絮凝脱色作用,其絮凝效果受聚合物的取代度、介质的pH 以及外加盐浓度的影响,而这些影响因素又直接与聚碱的离解行为或胺基离子化度(指已离子化的胺基占全部胺基的分数)密切相关.为此,本文对影响PAm·MG 离解行为和离子化度的一些因素作进一步探讨,并通过粘度测定考察离解行为对聚合物在水中形态的影响,为PAm·MG 的实际应用提供理论根据.     

絮凝处理对聚驱污水中部分水解聚丙烯酰胺浓度的影响

用常见无机和有机絮凝剂处理了聚驱污水,分别考察了絮凝剂单剂和复配处理后聚驱污水中残余部分水解聚丙烯酰胺(HPAM)质量浓度和透光率随絮凝剂剂量的变化.结果表明:采用无机絮凝剂处理聚驱污水时,残余HPAM质量浓度随絮凝剂剂量增加先减小后增大;采用有机絮凝剂处理聚驱污水时,残余HPAM质量浓度随絮凝剂剂量增加而线性增加.将无机絮凝剂与无机絮凝剂复配使用,则残余HPAM质量浓度与透光率成反比;将无机絮凝剂与有机絮凝剂复配使用,则残余HPAM质量浓度取决于复配体系中阳离子聚丙烯酰胺(CPAM)的添加量.     

端羟基聚环氧环己烷的合成

端羟基聚环氧环己烷的合成;端羟基聚环氧环己烷;环氧环己烷;阳离子聚合     

聚二甲基硅氧烷改性的聚氨酯齐聚物增韧环氧树脂

聚二甲基硅氧烷改性的聚氨酯齐聚物增韧环氧树脂;聚氨酯齐聚物;聚二甲基硅氧烷;环氧树脂;增韧;IPN     

电位型聚吡咯pH传感器的制备

电位型聚吡咯pH传感器的制备;聚吡咯; pH传感器; 电化学聚合; 交流阻抗     

聚天门冬氨酸合成过程中的水解反应

L-天门冬氨酸;;聚天门冬氨酸钠盐;聚丁二酰亚胺;水处理;阻垢作用;聚天门冬氨酸合成过程中的水解反应     

掺杂聚丙炔醇及其酯的湿敏特性

聚醋酸丙炔酯;湿敏性;掺杂聚丙炔醇及其酯的湿敏特性     

溶聚丁苯链化学结构的NMR研究

溶聚丁苯链化学结构的NMR研究;溶聚丁苯; 链化学结构; 相容性     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

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%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

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.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

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.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

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.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

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.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

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.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

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.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

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%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

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.