环糊精功能化单体制备的研究现状

环糊精聚合物是含有多个环糊精单元的高分子衍生物,兼具环糊精和高聚物二者良好的性能,在分子识别、分离分析技术、生物医学工程、环境等领域得到广泛的应用。环糊精聚合物的合成得到广泛关注,将环糊精单体功能化是制备环糊精聚合物的关键步骤。本文综述了β-环糊精单体功能化的几种制备方法,包括将环糊精修饰成带高反应活性的官能团、修饰成含乙烯基环糊精单体以及多取代官能团环糊精单体等。     

环糊精聚合物及其生物医学应用的研究进展

环糊精是一类由吡喃葡萄糖单元构成的大环分子,能够通过包结作用与多种小分子、金属离子以及聚合物形成主-客体包结物,从而实现对客体分子理化性能的调控,被广泛用于制药、食品、化学、色谱、催化、生物技术、农业、化妆品、卫生、医学、纺织和环境等领域.然而,环糊精分子在众多应用领域不易操控,通过化学交联制备环糊精聚合物,形成以环糊精为主体的聚合物,则有望实现环糊精与交联基团的"集成"和"协同"作用,不但能有效解决环糊精分子的操控问题,而且能够赋予环糊精单分子所不具有的独特功能和理化性质,因此环糊精聚合物的设计合成及其应用吸引了广泛的研究兴趣.本综述介绍了环糊精聚合物领域的研究近况,对环糊精聚合物的种类按结构与性质进行了分类,系统介绍了各类环糊精聚合物的制备方法,重点介绍了近五年环糊精聚合物取得的新突破,并详细论述了各类环糊精聚合物在生物医药中的应用和其他领域的代表性应用,最后对环糊精聚合物作了简要总结和展望.     

超支化聚合反应的多尺度模拟

超支化聚合物具有与树枝状大分子相似的物理和化学性质,其具有合成简单、分子量分布宽等突出特点,超支化聚合物分子的结构形成取决于聚合反应过程,本文介绍了超支化聚合反应模拟研究的最新进展.首先介绍了八位置键涨落粗粒化格子模型在超支化聚合反应模拟中的应用,该方法考虑了聚合物分子空间位阻效应、分子内成环和反应点活性等影响因素,从而可以模拟不同类型的超支化聚合反应;为了定量描述单体和聚合物分子结构,研究者进一步发展了杂化多尺度超支化聚合反应模拟方法,该方法通过玻尔兹曼反演迭代方法获取单体和聚合物特异性粗粒化力场,然后通过粗粒化分子动力学方法结合反应性Monte Carlo方法对特异性超支化聚合反应进行定量模拟.多尺度聚合反应模拟不仅可以精确计算超支化聚合物分子量、多分散性指数和支化度等一般性聚合物参数,还可以获取分子成环率、超支化大分子构象等重要分子结构信息,在超支化聚合反应基础研究与预测方面具有重要应用价值.     

基于环糊精的高度支化聚合物*

环糊精（CD）与高度支化聚合物都存在空腔结构,若将两者结合起来可构筑出含有两种不同疏水空腔且具有特异物理化学功能的高分子体系,并有望在分子包合与识别、药物控释、基因传输等领域得到新的应用。本文根据高度支化聚合物与环糊精结合方式的不同,从以环糊精为核的高度支化聚合物、外端悬挂环糊精的高度支化聚合物、高度支化聚合物的结构单元与环糊精包合、环糊精与客体分子包合后自组装成高度支化聚合物,以及用功能化的环糊精单体合成超支化聚合物等5个方面对其研究进展进行了总结和评述,并在此基础上展望了该类聚合物的研究方向和发展趋势。     

超分子聚合物制备新方法:超分子单体的共价聚合

超分子聚合物是超分子化学与高分子化学交叉的前沿研究领域,近年来受到了国内外研究学者的广泛关注.可控制备超分子聚合物对于研究超分子聚合物的结构与性能关系、设计合成特定功能的超分子聚合物具有重要的意义.本文将总结通过超分子单体的共价聚合反应以制备超分子聚合物的方法.不同于传统的制备超分子聚合物的方法,超分子单体的共价聚合方法将不易调控的非共价聚合转化为可控的共价聚合,为实现超分子聚合物的可控制备提供了新思路.     

环糊精键接聚合物的研究进展

环糊精键接聚合物是一种通过化学键将超分子主体环糊精和聚合物连接在一起的新型高分子。其既具有环糊精分子识别的特点,又兼具聚合物的各种优良性质。将二者通过共价键连接后,其在大分子机器、智能材料、分子组装等领域展现出更多新颖的特性,尤其是在生物医学、传感等方面有着潜在的应用价值。本文先介绍了传统环糊精分子的结构性质,并重点从合成方法和性能特点两方面综述了近些年来环糊精键接聚合物的研究进展,最后展望了环糊精键接聚合物的发展方向。     

环境响应性β-环糊精高聚物的合成及性能研究

环糊精聚合物既有着与其母体分子相同的分子包合及识别能力,又具有聚合物良好的机械强度、稳定性等,现已被广泛应用于色谱分离、医药等许多领域[1].由于环糊精分子的结构特点,使得线性环糊精高聚物的合成变得较为困难,其数量和种类非常有限[2].     

分子印迹球状β-环糊精聚合物的合成及性能研究

利用分子印迹技术,以β-环糊精为功能单体,甲苯-2,4-二异氰酸酯为交联剂,茶碱为模板分子,合成了分子印迹β-环糊精聚合物。采用反相悬浮聚合的方法,以戊二醛为交联剂,用聚乙烯醇(PVA)包埋环糊精聚合物合成了分子印迹球状β-环糊精聚合物(MI-CDPs)吸附剂,对聚合物的合成条件进行了考察,并利用静态吸附方法对球状MI-CDPs的吸附性能进行研究,结果表明,球状MI-CDPs对水溶液中的茶碱分子表现出良好的分子识别能力,实现了对水溶液中茶碱的分子识别,证实在pH=9时,球状MI-CDPs的吸附性能最佳。     

基于环糊精的原子转移自由基聚合

综述了近年来基于环糊精的原子转移自由基聚合的最新进展.其中,基于环糊精合成化学的原子转移自由基聚合主要表现在:一方面,通过原子转移自由基聚合反应实现环糊精母体的共价键修饰;另一方面,利用该反应参与构筑非共价键的环糊精自组装体系.而通过原子转移自由基聚合反应获得的这些新型环糊精衍生物和自组装体系还可以被进一步应用到有机合成化学、复杂“智能型”超分子自组装体系的构筑、药物输运与控缓释工具、蛋白识别以及手性分离等领域.     

环糊精聚合物的高分子效应

环糊精以其独特的包络性能而引人注目, 现已广泛应用于色谱分离、选择性合成的催化剂、食品、医药及农药等多种领域。环糊精聚合物被证实亦具有包络、缓释及催化的能力, 以及较好的机械强度和化学稳定性。目前环糊精聚合物主要应用在色谱分离、空气净化和食品工业等方面。本文综述了环糊精高分子化后所表现出的高分子效应, 为环糊精聚合物的合成和应用提供参考。     

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.     

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.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

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.