An intramolecular nitro-Mannich route to functionalised tetrahydroquinolines

A simple protocol for the diastereoselective synthesis of 3-nitrotetrahydroquinolines has been developed using an intramolecular nitro-Mannich reaction. In situ formation of an imine generated from treatment of 2-(2-nitroethyl)phenylamine with an aldehyde, in EtOH at room temperature, and subsequent addition of NH₄OH, led to the formation of trans-products in high yield and diastereoselectivity for 15 representative examples.     

Synthesis of 2,6-dimethyl-9-aryl-9-phosphabicyclo[3.3.1]nonanes: their application to asymmetric synthesis of chiral tetrahydroquinolines and relatives

Synthesis of 2,6-dimethyl-9-aryl-9-phosphabicyclo[3.3.1]nonanes from 1,5-cyclooctadiene and their application to asymmetric cyclization leading to chiral tetrahydroquinolines and relatives through palladium-catalyzed allylic alkylation are described.     

超分子有机框架:具有周期性孔结构的超分子聚合物

本文概述了水相周期性超分子有机框架(supramolecular organic frameworks,SOFs)的研究进展.首先介绍了水相超分子聚合物和多孔材料研究的背景,然后分别描述了二维单层、三维金刚石型和立方型SOF的构建、结构表征及功能.最后就SOF的未来应用前景做出了分析和展望.     

Potassium Vanadates of Mixed Valence as Sulfuric Acid Catalyst Precursors

The kinetics of hydrolytic precipitation of potassium vanadates K_xV₁₂O_31-δ ·nH₂O(0 < x ≤ 2.25; 0 <δ ≤ 1.15) from a KVO₃ solution at pH = 1.7 and 80°C in the presence of K₂SO₄ and VOSO₄ is controlled by second and third order reactions respectively occurring on the precipitate surface. This difference is due to the effect of VO²⁺ ions on the polymer anion [V₁₂ O_31-δ]ⁿ formation. Potassium vanadates K_xV₁₂O_31-δ ·nH₂O and K_xV₃O_8-δ·nH₂O (1.02 ≤ x ≤ 1.91; 0 ≤ δ ≤ 0.22) can be used as vanadium-containing precursors for sulfuric acid catalysts. This revised version was published online in June 2006 with corrections to the Cover Date.     

界面超分子聚合

超分子聚合物诞生于高分子化学与超分子化学的交叉融合,一般是指单体间通过非共价键作用连接形成的聚合物,并在溶液或体相中表现出类似聚合物的性质。目前超分子聚合物一般通过均相溶液聚合制备得到,但溶液中的超分子聚合是一个自发的组装过程,具有浓度依赖性,组装过程不易可控。为解决此问题,研究人员可以将超分子聚合从均相溶液转移到界面,在界面上可控地制备超分子聚合物。通过界面聚合制备超分子聚合物具有一些独特的优势,如可以制备得到分子量更高的超分子聚合物,易于制备一些缺陷少、面积大、有序的二维超分子聚合物等。本文基于在液-液、气-液和固-液三种界面上制备超分子聚合物的一些代表性工作,介绍了界面超分子聚合方法和应用,并展望其未来发展。     

Gemini型两亲分子超分子组装研究进展

综述了国内外对Gemini型两亲分子在超分子组装方面的研究进展。总结了Gemini分子的体相组装、界面组装以及近几年应用领域的研究进展;着重介绍了基因传递、纳米材料模板、降解剂、药物缓释以及胶凝剂的制备等方面的应用进展;对相关研究领域的主要研究成果做了一些探讨和分析;为更加深入探索和研究Gemini型两亲分子的超分子组装提供参考信息。     

超分子聚合机理

与共价键聚合物由单体(M1)通过共价键连接不同,超分子聚合物是由单体(M2)通过非共价键连接而成的长链大分子。聚合包括分子聚合和超分子聚合。超分子聚合描述M2通过非共价键自组装形成超分子聚合物的过程,涉及氢键、π-π堆砌型和立体匹配等驱动力以及分子识别、协同性等特征,与M1通过共价键形成聚合物的过程(分子聚合)不同。为了理解超分子聚合物链结构形成机理,本文分析和讨论超分子聚合的三个主要机理:(1)线性链生长;(2)螺旋链生长;(3)拓扑链生长。     

Facile and green synthesis of triarylmethanes using silica sulfuric acid as a reusable catalyst under solvent-free conditions

A facile and environmentally-benign protocol has been developed for the synthesis of triarylmethanes (TAMs) from the reaction of different arenes and aldehydes in the presence of silica sulfuric acid (SSA) as a heterogeneous and reusable catalyst under solvent-free conditions. Easy work-up, short reaction times, high yields, high selectivity, mild and green conditions are other salient features of this method.     

Supramolecular surfactants derived from calixarenes

Supramolecular surfactants self-aggregate via noncovalent interactions. The process is rapid and reversible which makes them potentially useful for the design of stimuli-responsive systems. Here we focus on host:guest interactions using calixarenes as molecular receptors. Calixarenes are an important family of molecular receptors because of their ease of preparation and post-modification. The calixarenes discussed here cannot self-aggregate, but when combined with an appropriate guest molecule readily self-associate. Different types of aggregates are obtained, e.g., micelles or vesicles, depending upon the structures of the calixarene and guest.     

Supramolecular chemistry

The article discusses molecular recognition and overviews the key concepts -storage and retrieval of chemical information by molecular structures, supramolecular reagents and catalysts, molecular transport, semiochemistry and self assembly. The prospects of controlling supramolecular architecture through engineered molecular recognition and design of ‘programmed systems’ controlled by molecular information are also discussed.     

A green method for the synthesis of bis–indolylmethanes and 3, 3'-indolyloxindole derivatives using cellulose sulfuric acid under solvent-free conditions

<正>A highly efficient green protocol for the preparation of bis-indolylmethanes,bis-2-methylindolylmethanes,bis-1-methylindolylmethanes and 3,3'-diindolyloxindole derivatives from the reaction of indoles with various aldehydes and ketones in the presence of cellulose sulfuric acid under solvent-free conditions is reported.The significant features of this procedure are high yields of the products,mild reaction,solvent-free condition and non-toxicity of the catalyst.     

超分子化学在药物共晶中的应用

药物共晶是一种新兴的药物晶型, 一个给定的活性药物分子通过形成共晶, 一方面可以大大丰富其结晶形式, 另一方面可以改善其物化性质及临床疗效. 本文从超分子化学的角度对药物共晶进行了综述, 列举了一系列通过氢键超分子合成子进行药物共晶设计和制备的研究实例, 旨在促进超分子化学和药学的交叉融合.     

Supramolecular enzyme mimics by self-assembly

The development of supramolecular chemistry has led to a shift in the research focus from the structural design of supramolecules to developing functional systems, such as supramolecular enzyme models. The supramolecular enzyme mimics can be readily constructed by self-assembly which is an efficient strategy for generating highly-ordered structures with complex and hierarchical architectures to mimic the biopolymers. The study of supramolecular enzyme mimics has implications for understanding both the structure–function relationships of natural enzymes and the thermodynamic mechanism during catalysis. Additionally, they are potentially useful in many important applications, e.g., medicinal application and industrial biocatalysts and so on. This review is aimed at giving a brief overview of the synthesis of supramolecular enzyme mimics and their functions.     

多酸-环糊精超分子体系的研究进展

综合评述了近些年来基于环糊精的多金属氧簇超分子体系的代表性工作, 以参与构建的多酸-环糊精超分子复合物中不同多酸的结构类型为分类依据进行了相应的归纳概述. 希望本文可以引起读者对于多金属氧簇-环糊精超分子体系的研究兴趣, 并为研究者提供一些新的思路和启发.     

A new approach to 2,2-disubstituted chromenes and tetrahydroquinolines through intramolecular cyclization of chiral 3,4-epoxy alcohols

An efficient route to chiral chromene and tetrahydroquinoline ring models 3 and 4 was developed by means of the vanadium epoxidation of chiral homoallylic alcohols 12 and 19 followed by an intramolecular epoxide opening of 3,4-epoxy alcohols 14 and 20. The configuration of all compounds was confirmed using NMR analysis.     

Expeditious Pechmann Condensation by Using Biodegradable Cellulose Sulfuric Acid as a Solid Acid Catalyst

A facile synthesis of coumarins was performed in excellent yields via Pechmann condensation by using different type of phenols and ethylacetoacetates under solvent–free media using both conventional method and microwave irradiation in short reaction times is described. The reaction workup is very simple, and the catalyst can be easily separated from the reaction mixture and reused several times in subsequent reactions.     

光响应超分子聚合物

超分子聚合物是超分子化学、高分子化学和材料化学领域的研究热点.将光响应的功能基团以非共价作用构筑到超分子聚合物体系中,得到光响应型超分子聚合物,从而能够将超分子聚合物的独特性质与光化学反应的优势有效地结合起来,从而构筑新型的光功能材料.本文总结了近年来本课题组有关光响应超分子聚合物方面的研究工作:介绍了主链型的光响应超分子聚合物的光调控组装和解离,超分子聚合物和共价聚合物的光控可逆切换和光调控组装形貌;另外还举例介绍了具有自修复和室温磷光发射等功能的侧链型光响应超分子聚合物,并对刺激-响应的超分子聚合物领域的发展做了展望.     

三聚氰胺和对苯二氧乙酸共晶中的三维氢键网络

合成了一个新的超分子聚合物{(MAH+)2(p-BDOA2-)·4H2O}n(MA=三聚氰胺;p-BDOAH2=对苯二氧乙酸),通过X-射线对其结构进行了表征。在该聚合物中,三聚氰胺被质子化,相邻的三聚氰胺分子通过氢键形成一维阳离子链(MAH+)n,相邻的阳离子链由p-BDOA2-阴离子连接构成波浪状的二维层,层状结构通过水分子的氢键和π-π堆积形成三维结构。     

pH-Responsive Phase Transition of Supramolecular Hydrogel Consisting of Glycosylated Amino Acetate and Carboxylic Acid Derivative

By addition of a carboxylated amino acetate (2) to a low-molecular-weight hydrogel (1) which has a unique thermally induced volume-phase transition character, a macroscopic pH-responsive feature is newly conferred on the supramolecular hydrogel. The direct observation of temperature-dependent behavior of the mixed hydrogel clearly showed that the thermally induced swelling-shrinkage type of the volume phase transition at pH 4 is shifted to the gel–sol transition at pH 7 by 10?mol% addition of 2 to the hydrogel 1. On the basis of the measurements by TEM, SEM, XRD and FT-IR, it is conceivable that incorporation of the anionic carboxylate of 2 slightly disturbs the packing of the hydrogen bond belt of the mixed hydrogel. Such a slight disturbance greatly leads to the sol–gel transition by elevating temperature, instead of the volume-phase transition. Introduction of dynamic characteristics to supramolecular systems in a macroscopic level may extend the potential of these materials in various fields.