胺类末端官能化聚合物的研究进展

简要介绍了胺类末端官能化聚合物的国内外发展状况,按照伯胺类、仲胺类、叔胺类三类封端剂合成的官能化聚合物进行了分类介绍,对于利用不同的胺类封端剂合成官能化聚合物的官能化反应的机理、反应条件和反应特点进行了深入的分析对比,叙述了从苛刻的低温反应条件到室温或更高反应温度、从需要添加极性调节剂到使用非极性烃类做溶剂和从单一特殊的官能化封端反应到通用的官能化封端反应的发展历程,并对未来胺类末端官能化聚合物的发展进行了展望。     

基于双锂法的炔基功能化热塑性弹性体的合成

苯乙烯-异戊二烯-苯乙烯三嵌段聚合物(SIS)是目前广泛使用的一种热塑性弹性体(TPE)材料, 建立高效、 精准、 普适的SIS功能化方法一直是提高TPE材料性能的关键. 首先, 利用双烯单体与单官能度引发剂的反应合成了双官能度的双锂引发剂; 然后采用双锂引发法, 以炔基功能化单体封端, 高效合成了α,ω-端炔基官能化SIS聚合物. 采用叔丁醇锂作为异戊二烯聚合段的调节剂, 叔丁醇钾作为苯乙烯聚合段的调节剂, 合成了低乙烯基结构含量(5.8%)、 窄分子量分布(<1.17)的SIS三嵌段聚合物; 再向SIS三嵌段聚合物中一步加入炔基官能化的1,1-二苯基乙烯(DPE)衍生物进行封端, 以高于90%的收率高效合成了α,ω-端炔基官能化SIS三嵌段模块聚合物, 借助炔基的高效点击反应, 实现了功能化及拓扑化TPE材料的制备.     

Enzymes动能化的树形高分子: 蛋白和酶的人工模型

含有官能机制特殊树枝状聚合物可作为生物有机分子, 如蛋白质及酵素的模型。本文将介绍这类型官能性树枝聚合物的制备方法。     

单体慢加入技术对超支化聚合物分子参数的影响

详细分析了单体慢加入到多官能度核分子中制备超支化聚合物的动力学过程,以单体转化率为参数导出了产物的聚合度分布函数、平均聚合度、多分散性指标和支化度等分子参数的解析式,计算结果与文献报道的实验数据十分一致.分子参数依赖于核的官能度(f)、核分数(α)和单体转化率(x),这为通过聚合反应条件来进行分子结构的设计提供了理论依据.与一步聚合方法的产物相比,单体慢加入技术能够改进产物的分子量分布,提高其支化度.     

氟烯烃的活性/可控自由基聚合研究进展

含氟聚合物具有优异而独特的性能,主要是通过氟烯烃的聚合反应合成的。自从上世纪90年代以来,活性/可控自由基聚合反应获得极大的进展,发展了多种活性自由基聚合的方法,为聚合物的精确设计、合成提供了强有力的手段。氟烯烃的活性/可控自由基聚合反应研究始于上世纪70年代,碘转移聚合已经成功地应用于含氟热塑性弹性体的商业化生产。文献已经报道的氟烯烃活性/可控自由基聚合反应包括碘转移聚合(ITP)、烷基硼自由基聚合、原子转移自由基聚合(ATRP)和可逆加成断裂链转移聚合(RAFT)或黄原酸酯交换法(MADIX)等。通过这些方法可以制备出分子量确定、结构多样化的含氟聚合物,如嵌段、接枝和遥爪聚合物等,使含氟聚合物的应用范围得到进一步拓展。本文结合本课题组的研究工作,对氟烯烃活性/可控自由基聚合反应的研究进展进行了简要综述。     

可用于建材防水涂料的含氟聚氨酯的研制及性能研究

以聚醚二元醇和异氰酸酯合成两端含异氰酸酯基的聚氨酯预聚物,将含氟醇与聚氨酯预聚物进行反应,得到端基含氟的聚氨酯,制备了一系列含氟聚氨酯涂料。对涂料的性能研究显示,聚合物对基材具有良好的附着力,且随着含氟量的增大,制备的含氟聚氨酯涂层对水及乙二醇的接触角数值逐渐增大,表面能和吸水率逐渐降低;聚合物体系均一,未发生相分离。表明通过化学方法将含氟链段引入聚氨酯结构,得到了稳定的含氟聚氨酯聚合物,且涂料的表面性能得到提高。该含氟聚氨酯在建材防水涂料领域有广阔的应用前景。     

热致相分离法制备聚合物微孔材料

热致相分离是一种制备聚合物微孔材料的有效方法。本文介绍了聚合物初始浓度、聚合物分子量、稀释剂、冷却速率、萃取剂、聚合物密度等因素对热致相分离法制备聚合物微孔材料的影响,并对热致相分离法制备新型微孔材料的最新研究进展进行了综述。     

乳液聚合的最新进展（上）

本文对近１０多年中发展起来的与乳液聚合相关的聚合技术，如无皂乳液聚合、细乳液聚合、微乳液聚合、分散聚合等，也对其实施方法、理论研究结果和应用作了介绍；还针对近年来已经成为热点的核壳乳液、单分散聚合物微球及表面官能化的乳液微球的制备方法及应用进行了综述。     

结构与制备条件对两亲性偶氮聚合物胶体球尺寸和光响应性的影响

合成了3种具有不同官能团或官能化度的双亲性多分散偶氮聚合物.系统研究了它们在选择性溶剂中形成聚合物胶体球时,各种因素对胶体球尺寸和光响应性能的影响规律.结果表明,不仅官能团和官能化度对胶体球的尺寸与光响应性有明显影响,具体的制备条件(如初始浓度、沉淀剂加入速率等)对胶体球尺寸和光响应性能也有重要影响.聚合物胶体球的粒径随官能化度的增加而增大;随初始浓度的增加和沉淀剂加入速率的减小而增大.聚合物PEAPE胶体球的光致异构化速率快于PCNPE胶体球的光致异构化速率.聚合物胶体球的光致异构化速率随官能化度的增加而减小;随初始浓度的增加和沉淀剂加入速率的减小而减小.这些影响表现出了明显的规律性.从双亲性聚合物在选择性溶剂中自组装形成胶体球的热力学与动力学因素出发,讨论了上述现象产生的原因.     

“梳形”含氟功能聚合物的构建与应用

含氟化合物因具耐热性、耐化学性和低表面能等优异性能,在设计具有特殊功能和特定化学物理性质的功能聚合物时展现出优秀的特性。然而目前大部分含氟聚合物仍是通过传统的自由基聚合获得,难以对聚合物的聚合过程进行调控,导致具有新型结构的含氟聚合物的构建较为困难。随着可控/活性自由基聚合方法的发展,如原子转移自由基聚合(atom transfer radical polymerization, ATRP),可逆加成-断裂链转移聚合(rever-sible addition-fragmentation chain transfer polymerization, RAFT)和开环易位聚合(ring opening metathesis poly-merization, ROMP)等,构建新型结构的含氟聚合物成为可能。通过对含氟聚合物的聚合过程和结构的精准控制,结合“grafting-from”、“grafting-to”和“grafting-through”三种接枝方法可得到“梳形”结构的含氟聚合物。由于含氟链段的高温自迁移性,将含氟链段作为“梳段”,使其具有独特的物理化学性质,在光电、生物医药等高端...     

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.     

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.     

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.     

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.