脂肪酸蔗糖酯非离子表面活性剂的合成和性能

应用超声技术合成了辛酸蔗糖酯(SE8)、月桂酸蔗糖酯(SE12)、肉豆蔻酸蔗糖酯(SE14)和棕榈酸蔗糖酯(SE16),表征了它们的表面张力、临界胶束浓度(CMC)、亲水亲油平衡值(HLB)以及它们的润湿性能、乳化性能;并采用32#机油污染铂黑电导电极测试了蔗糖酯表面活性剂的净洗性能。结果显示,蔗糖酯(SE8、12、14、16)非离子表面活性剂具有低于传统表面活性剂的表面张力和CMC,且具有较好的乳化性、优异的润湿性和净洗性。     

聚(2-丙烯酰胺甲基-6-十二烷基硼酸二乙醇胺酯)与十二烷基苯磺酸钠混合溶液的表面活性

聚(2-丙烯酰胺甲基-6-十二烷基硼酸二乙醇胺酯)(PADB)是一类两亲性聚硼酸酯.本文通过表面张力法考察了不同相对分子质量的PADB水溶液的表面活性;重点研究了PADB与十二烷基苯磺酸钠(SDBS)在0.5 mol.L-1 NaCl溶液中的相互作用,通过正规溶液理论,计算PADB/SDBS混合体系的胶束化参数,并与单体ADB/SDBS混合溶液体系进行了比较.结果表明,PADB相对分子质量可达1.5×104-3.5×104,随分子量增加,PADB水溶液中临界胶束浓度(cmc)增大,但cmc时的表面张力(γcmc)维持在31 mN.m-1左右(298 K);加入PADB后,SDBS溶液表面张力-浓度对数(γ-lgc)曲线出现两处转变点,即c1和c2点,但c1和c2皆小于纯SDBS溶液的临界胶束浓度(cmcSDBS),即c1c2cmcSDBS.PADB加入量越大,相对分子质量越低,SDBS溶液的表面活性越强.将聚硼酸酯PADB溶液视为特殊状态的单体ADB溶液,通过近似处理,计算得到PADB/SDBS混合胶束中相互作用参数βm在-2.4到-4.7之间,活度系数f1m1,表明聚硼酸酯PADB与SDBS有较强的相互作用;当混合体系中PADB的ADB结构单元摩尔分数x1为0.47时,|βm|达到最大.相比于单体ADB/SDBS混合体系,当x10.8时,PADB/SDBS混合体系|βm|值较大,相互作用更强;随x1增大,混合胶束中聚合物PADB的ADB结构单元摩尔分数x1m不断增加,但其值低于ADB/SDBS混合体系.     

基于丙二酰胺的不对称双子表面活性剂的合成及其乳化性能

将二(3-二甲氨基丙基)丙二酰胺分别与溴代十六烷和溴代十四烷反应,生成的季铵盐化产物经丙酮-乙腈重结晶,得到含丙二酰胺基的不对称阳离子双子(Gemini)表面活性剂(命名为16-9-14),总收率为45.9%(以溴代十六烷计);利用红外光谱和核磁共振谱表征了合成产物的结构,采用电导法测定了其临界胶束浓度(CMC),采用滴体积法测定了其临界张力(γCMC),进而初步探讨了其发泡沫性能和乳化性能.结果表明,合成的Gemini表面活性剂的CMC为1.57×10-4 mol/L,γCMC为38.45mN/m;其发泡性能和乳化性能优于相应的单子表面活性剂.     

聚谷氨酸基双重响应性纳米胶束的制备及药物控释性能

首先制备端氨基聚(N-异丙基丙烯酰胺-co-聚乙二醇)大分子引发剂,再通过端氨基引发L-谷氨酸-γ-苄酯-N-羧酸酐开环聚合,制备了聚(N-异丙基丙烯酰胺-co-聚乙二醇)与聚(L-谷氨酸-γ-苄酯)的嵌段共聚物,将其中的γ-苄酯基团转化为酰肼基团后与阿霉素(DOX)共价结合,最后在水溶液中自组装成纳米胶束,制备了温度和pH值双重响应性纳米胶束。胶束外层由亲水性聚(N-异丙基丙烯酰胺-co-聚乙二醇)组成,具有温敏性,低临界溶液温度为38℃;胶束内层由聚(L-谷氨酸-γ-酰肼-阿霉素)组成。该胶束对于药物的释放具有温度和pH双重敏感性。     

光-碱双重可降解阳离子表面活性剂的合成与性能

以香草醛、溴代十二烷、硝酸等为原料,通过O-烷基化、硝化、还原、酯化、成盐五步反应,合成了一种含邻硝基苄酯的可光-碱双重降解的吡啶盐阳离子表面活性剂.中间体与目标产物都进行了1H NMR结构表征;所得阳离子表面活性剂的临界胶束浓度(CMC)值约为0.3 mol·L-1.以该表面活性剂为乳化剂,进行苯乙烯乳液聚合可以得到稳定的乳液,表明该表面活性剂具有良好的乳化性能.将乳液进行紫外光照2h,可明显观察到乳液破乳并变色.经光降解测试证实该表面活性剂可在光作用下降解;发泡测试表明该表面活性剂具备一定的发泡性能;pH降解测试表明表面活性剂可在pH为7～9下实现碱降解.     

磷酰胆碱基pH敏感性ABA型嵌段共聚物的合成与胶束化

采用氯化亚铜/2,2-联二吡啶催化体系, 2,5-二溴己二酸二乙酯为引发剂, 甲醇为溶剂运用希莱克技术, 利用原子转移自由基聚合(ATRP)方法合成了ABA型三嵌段共聚物PDEAEMA-b-PMPC-b-PDEAEMA. ¹H NMR和GPC(凝胶渗透色谱)对聚合物组成、结构及分子量进行了表征, 利用透光率、粘度测定研究了嵌段共聚物溶液的pH敏感性, 利用表面张力测定、荧光探针和透射电镜研究了嵌段共聚物胶束化作用, 确定了共聚物水溶液的临界胶束浓度(CMC). 结果表明所合成的ABA型三嵌段共聚物水溶液具有pH敏感性, 其临界相变pH 7～7.5. 调节溶液pH值可实现嵌段共聚物胶束化形成“花状”胶束, 并测定了其临界胶束浓度.     

星型共聚物PEO_3-b-PDMAEMA_3的pH敏感和温敏性研究

本课题组结合阴离子开环聚合技术和原子转移自由基聚合技术,以环氧乙烷(EO)和甲基丙烯酸[2-(二甲基氨基)乙基]酯(DMAEMA)为单体,合成了分子量可控、分子量分布窄的星型嵌段共聚物PEO3-b-PDMAEMA3。基于PEO的亲水性和PDMAEMA的温敏和pH敏感性,我们用荧光光谱仪、动态激光散射仪等比较研究了该系列星型嵌段共聚物在水溶液中的温敏及pH敏行为,证明其具有温敏和pH敏感性,而且其临界胶束化pH值要小于相应的线型嵌段共聚物的临界胶束化pH值。     

ARGET ATRP 与ROP 结合制备pH 响应两亲性聚合物分子刷及其自组装研究

结合电子转移活化剂再生-原子转移自由基聚合(ARGET ATRP)和开环聚合(ROP)法合成了一种具有无规疏水/ pH 响应结构的两亲性聚合物分子刷聚(甲基丙烯酸聚丙交酯酯-co-甲基丙烯酸)-b-聚甲基丙烯酸单甲氧基聚乙二醇酯 [P(PLAMA-co-MAA)-b-PPEGMA]. 通过核磁共振氢谱(¹H NMR)和凝胶渗透色谱(GPC)表征了聚合物的结构、分子量及分子量分布. 优化了反应条件并合成出分子量可控、分子量分布窄的聚合产物. 采用动态光散射法(DLS)、扫描电子显微镜(SEM)研究了聚合物分子刷在水溶液中自组装胶束的粒径、形貌及pH 响应行为. P(PLAMA-co-MAA)-b-PPEGMA 自组装形成粒径分布均匀的球形胶束. 且随着溶液pH 值从7 降低至3, 胶束中的PMAA 逐渐去离子化, 溶胀的胶束逐渐收缩, 粒径由200～300 nm 减小至150 nm 左右; 但当pH 值减小到2 以下, 胶束表面电荷量非常小, 胶束聚集, 使得粒径增大.     

壬基酚聚氧乙烯醚型Gemini季铵盐表面活性剂的合成 及其表面性质的研究

合成了系列壬基酚聚氧乙烯醚型Gemini季铵盐表面活性剂(GNPQA), 用核磁、红外和元素分析对它们的结构进行了表征, 考察了反应条件对转化率的影响, 并用表面张力法和稳态荧光探针法对GNPQA的表面性能及胶束聚集数(N)进行了研究. 结果表明, 较优的反应条件: 反应时间为12 h, 反应温度为70 ℃, 反应原料摩尔比为n(双聚壬基酚聚氧乙烯醚)∶n(三乙胺)∶n(环氧氯丙烷)＝1∶1∶1; GNPQA的临界胶束浓度(CMC)值较相应的单体壬基酚聚氧乙烯醚型季铵盐表面活性剂(NPQA)降低了1～2个数量级, 显示了较高的表面活性; 当GNPQA溶液浓度为5～9倍CMC时, N值随浓度增大而线性增大; 随着氧乙烯(EO)单元数的增长, GNPQA的CMC和N值均逐渐减小; 结合GNPQA的表面性能参数和N值的变化规律, 探讨了这类表面活性剂表面及胶束聚集体的结构形态.     

聚硼酸酯表面活性剂囊泡自发形成

通过直接引发聚合, 以偶氮二异丁腈为引发剂, 用N-羟甲基丙烯酰胺、硼酸三乙酯和N,N-二羟乙基十二烷基胺制备了聚硼酸酯(PMBE)表面活性剂, 用红外光谱、核磁共振谱和凝胶色谱对其结构进行了表征; 用透射电镜(TEM)研究了PMBE在纯水和0.1 mol/L NaCl水溶液中的自组装形态. 结果表明, PMBE在水和0.1 mol/L NaCl溶液中皆可自发形成聚合囊泡; 在水溶液中PMBE囊泡粒径约为20 nm, 而NaCl溶液中囊泡直径增大, 在150~250 nm之间, 分布较为均匀; 结合两亲性分子排列参数理论和一定的近似处理方法对PMBE聚合囊泡的形成机理进行了初步探讨.     

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.     

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.     

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.     

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.