选择性接聚乙烯醇枝聚醚氨酯的合成及其血液相容性

合成了α－甲基，ω－（２，３－环氧丙基）－聚乙二醇醚（Ⅱ）．经水解得到悬挂聚乙二醇（ＰＥＧ）枝的丙二醇－２，３（Ⅲ）．用二元醇（Ⅲ）为扩链剂制得了在硬链段上接有ＰＥＧ枝的聚醚氨酯（Ｈ－ＰＥＵ）．以四氢呋喃与少量大分子单体（Ⅱ）进行正离子开环共聚合制得每个链接有约１．３个ＰＥＧ枝的聚丁二醇（Ⅳ），用以合成了在软链段上接有ＰＥＧ枝的聚醚氨酯（Ｓ－ＰＥＵ）．ＥＳＣＡ及抗凝血性研究结果表明，不同位置接枝的ＰＥＵ，其表面都有明显的聚醚链段富集．Ｓ－ＰＥＵ抗凝血复钙时间只比未接枝者增长约２０％，而Ｈ－ＰＥＵ则增约一倍，比Ｓ－ＰＥＵ增约６０％．随ＰＥＧ最增大，复钙时间增长．     

可生物降解的聚乳酸弹性体的合成与表征

本文将丙交酯（ＤＬ－ＬＡ）与聚乙二醇（ＰＥＧ）的预聚体用甲苯－二异氰酸酯８０（ＴＤＩ）扩链，得到了一系列的聚乳酸（聚醚）型聚氨酯（ＰＥＧ－ＰＬＡ／ＰＵ）弹性体。对预聚体和弹性体分别进行了ＩＲ、ＨＮＭＲ和ＤＭＡ表征，并测定了弹性体的力学性能。结果表明，ＬＡ与ＰＥＧ生成的预聚体是一种三嵌段结构：ＨＯ－ＰＬＡ－ＰＥＧ－ＰＬＡ－ＯＨ。随着ＰＥＧ含量的增加，弹性体的玻璃化温度下降；ＰＥＧ分子量增大时，弹性体     

IR研究聚氨酯预聚反应的活化能

在滴定分析判断聚乙二醇（ＰＥＧ）和２，４－二甲苯二异氰酸酯（ＴＤＩ）预聚反应为一级反应的基础上，用ＩＲ分析ＰＥＧ和ＴＤＩ预聚反应过程中ＮＣＯ基的定量变化，结合Ａｒｒｈｅｎｉｕｓ经验式得ＰＥＧ入ＴＤＩ预聚反应的表观活性能Ｅα＝８６．９ｋＪｍｏ６－２，为研究其预聚反应的历程奠定基础。     

微米级聚酯醚嵌段共聚物微球的制备及其蛋白包裹研究

聚酯 醚嵌段共聚物聚 Ｄ，Ｌ 乳酸 聚乙二醇（Ｐｏｌｙ ＤＬ ｌａｃｔｉｄｅ Ｐｏｌｙｅｔｈｙｌｅｎｅｇｌｙｃｏｌ，ＰＬＡ ＰＥＧ）采用本体聚合法在１８０℃及－９５×１０－２ＭＰａ条件下制得．光谱分析证实产物结构．采用乳液溶剂蒸发法制备ＰＬＡ ＰＥＧ微球，粒径＜５μｍ．以复合乳液技术包裹蛋白．差示扫描量热分析确证ＰＬＡ ＰＥＧ有效包裹蛋白．ＢＣＡ法检测微球蛋白含量．结果表明与均聚物ＰＬＡ比较，ＰＬＡ ＰＥＧ不仅改善了成球条件而且蛋白的包裹效率明显提高．     

聚乙二醇改性聚对苯二甲酸乙二酯／聚对苯二甲酸丁二酯共混体系研究 Ⅱ．结晶形态和分子量及动态力学性能

本文研究工作表明，聚乙二醇（ＰＥＧ）作为聚对苯二甲酸乙二酯（ＰＥＴ）／聚对苯二甲酸丁二酯（ＰＢＴ）共混体系的结晶促进剂．不仅使聚合物分子链运动容易而有利于结晶时定向排列，晶体生成速度加快．而且使成核剂的成核效率提高，晶核生成速度加快，晶核数目增多而晶体尺寸减小．此外，ＰＥＧ还部分参与了聚酯的酯交换反应，在低用量时有利于聚合物特性粘数提高，而用量增大则引起聚酯降解．由于ＰＥＧ的这些作用，共混体系在ＰＥＧ为６．０％时的模量及γ－衰减强度最大．动态力学性能最好．     

甲壳胺-g-PEG的合成及医用性能的研究(Ⅰ)甲壳胺-g-PEG的合成及表征

通过官能团偶联反应，将端基改性为醛基的甲氧基聚乙二醇（分子量分别为２０００、５０００），按不同配比与甲壳胺反应，制得了甲壳胺接枝ＰＥＧ的产物（Ｃｈｉｔｏｓａｎ－ｇ－ＰＥＧ）。讨论了反应的最佳ｐＨ条件。建立了有效的产物分离方法，用红外光谱法、１Ｈ－ＮＭＲ法对产物的本体结构进行了表征，并用元素分析法和１Ｈ－ＮＭＲ法对接枝量进行了测定。     

不饱和聚酯／聚氨酯复合体系的研究

以端羟基不饱和聚酯（ＨＵＰ）与聚氨酯（ＰＵ）浇注型复合网络聚合物（ＣＰＮｓ）为基材，考察了化学动力学及相分离对ＣＰＮ聚合物物理机械性能的影响．数据揭示了不饱和聚酯／聚附聚氨酯（ＨＵＰ／ＰＵ－ｅｓ）ＣＰＮ，当ｒ＝ＮＣＯ／ＯＨ＝０．４时，它的物理力学性能优于不饱和聚酯／聚醚聚氨酯（ＨＵＰ／ＰＵ－ｅｔ）ＣＰＮ或ＨＵＰ／ＰＡＰＩＣＰＮ组成物．最佳ＣＰＮ可通过调整聚氨酯中软段和硬段组分及网络组成而设计与制备．     

聚乙二醇—硫酸铵—亚硝基R盐体系中钴（Ⅱ）的分离及其存在形态

在ｐＨ４．０～６．０的ＨＡｃ－ＮａＡｃ缓冲溶液中，Ｃｏ（Ⅱ），Ｆｅ（Ⅲ），Ｎｉ（Ⅱ），Ｃｕ（Ⅱ）等金属离子与亚硝基Ｒ盐可形成稳定络合物，加入ＨＣｌ适当提高溶液酸度（ＨＣｌ浓度在０．３～０．６ｍｏｌ／Ｌ）用聚乙二醇２０００（ＰＥＧ）－硫酸铵－亚硝基Ｒ盐体系萃取，Ｃｏ（Ⅱ）可被ＰＥＧ相几乎完全萃取，而Ｆｅ（Ⅲ），Ｎｉ（Ⅱ），Ｃｕ（Ⅱ）基本上不被萃取，实现了Ｃｏ（Ⅱ），Ｆｅ（Ⅲ），Ｎｉ（Ⅱ），Ｃｕ（Ⅱ）     

聚乙二醇改性聚对苯二甲酸乙二酯／聚对苯二甲酸丁二酯共混体系研究 Ⅱ．结晶形态和分子量及动态力学性能

本文研究工作表明，聚乙二醇作为聚对苯二甲酸乙二酯（ＰＥＴ）／聚对苯二甲酸丁二酯（ＰＢＴ）共混体系的结晶促进剂，不仅使聚合物分子链运动容易而有利于结晶时定向排列，晶体生成速度加快，而且使成核的成效率提高，晶核生成速度加快，晶核数目增多而晶体尺寸减小，此外，ＰＥＧ还部分参与了聚酯的酯交换反应，在低用量时有利于聚合物特性粘数提高，而且量增大则引起聚酯降解。由于ＰＥＧ的这些作用，共混体系在ＰＥＧ为６．０％     

含偶氮苯生色团的聚醚的合成与热致液晶性质

β－氯乙基缩水甘油醚（ＧＣＥ）和ＧＣＥ／羟丁基乙烯基醚（ＨＢＶＥ）分别通过阳离子聚合、光引发共聚合,获得两种聚醚,然后再分别与４－硝基－４’－羟基偶氦苯（ＮＨＡ）反应,制备了两种侧链含偶氦苯生色团的液晶聚合物（ＰＡＥＧ、ＰＡＶ）。用ＦＴＩＲ、＾１Ｈ－ＮＭＲ和ＥＡ对其化学结构及生色团含量进行了表征,以ＰＯＭ,ＤＳＣ、ＴＧＡ和ＷＡＸＤ对聚合物介晶相转变温度、织构、热稳定性及相行为进行了研究。结果表明,     

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%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

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.     

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.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

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.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.