The Application of Combinatorial Chemistry in Catalysis

In recent few years combinatorial methodology has been extensively used in material science research. Based on the desired properties of materials, various high throughput synthesizing and screening technologies were developed. These high throughput technologies can increase our speed to more than hundred folds for finding and optimizing materials. One of the most active areas is catalysis. Scientists are developing novel high throughput technologies to screen catalyst libraries to find and optimize new catalysts for chemical industry. In this area die key is combinatorial catalytic reactor design, catalyst library synthesis, and product detection. Systematic technologies for catalyst library synthesis and characterization were developed in our laboratory. In this work, catalyst in situ synthesis, parallel reactor design, and detection methods will be introduced. Combining with the powerful combinatorial methodology, good chemistry design will make our work even more efficient. Hence, as an example of combining combinatorial technologies with chemistry design, a successful catalyst design is also introduced.     

Strategies for the Dynamic Integration of Combinatorial Synthesis and Screening

Selection and amplification of only those components with the desired property–the integration of combinatorial chemistry and screening makes this possible. If the components of a combinatorial library are in a reversible equilibrium, the desired components can be selected and amplified by shifting the equilibrium of the mixture (see schematic representation).     

Crown Ethers and Phase Transfer Catalysis in Polymer Chemistry

Abstract

This paper is the first half of a two part review on the applications of crown ethers, cryptands, glymes and various onium ion salts to polymer chemistry. Part 1 surveys the use of these phase transfer catalysts (PTC's) in the synthesis and modification of macromolecules. Applications to ring-opening and vinyl polymerizations generally have involved solubilization and activation by PTC's of organic and inorganic salts which serve as anionic initiators. Change in the polymerization rates, polymer yields and product microstructure often resulted from association of the PTC with the active chain end.

Polymer modification and functionalization reactions have been enhanced by the use of PTC's. Macromolecular substrates have included both soluble and insoluble polymers, although the most popular have been the readily-available Merrifield resins. Generally these two-phase reactions have involved polymer solutions interacting with insoluble reagents or insoluble polymers reacting with the reagent solution. Some of the groups incorporated have been thiols, nitriles, carboxylic acids, esters, and crown ether analogs themselves. Most of this work has aimed at synthesis of polymer derivatives which can serve as chelating agents, catalysts and reagents in subsequent reactions. In almost all cases described, phase transfer catalysis offers definate advantages in selectivity and yield over conventional methods. The outline below gives the general subject areas of both Part 1 and Part 2; the latter will be published shortly.     

固相合成及组合化学用的高聚物载体

综述了用于固相合成及组合化学的高聚物载体的制备方法、特征、应用和最新进展,重点介绍了目前广泛用作固相载体的交联聚苯乙烯树脂、聚酰胺树脂和TentaGel树脂,并对几类新型载体如聚乙二醇、聚四氢呋喃衍生物交联剂改性的聚苯乙烯树脂、非芳环体系的POEPOP,树脂和SPOCC树脂作了简要的概述。     

手性催化与合成中的一些凝聚态化学问题

凝聚态化学作为一门研究化学反应中凝聚态物质的科学,最近引起了化学界的广泛关注。从手性化学角度出发,本文列举了近年来手性催化与合成中的一些凝聚态化学现象,分类介绍了不对称催化反应中不同类型的凝聚态物质,并通过列举实例分析讨论了凝聚态物质的具体组成、层次结构等因素对反应的催化活性、对映及区域选择性控制影响,以望能引起业界对凝聚态科学的关注,启发更多学者从凝聚态化学角度思考有机化学反应本质并解决相关问题,完善凝聚态科学体系。     

Microwave Induced Synthesis of 3,4-Dihydro-2H-pyran-2-carboxaldehyde: A Versatile Linker for Solid Phase Combinatorial Library

Procedures for the dimerization of acrolein to form 3,4-dihydro-2H-pyran-2-carboxaldehyde by microwave induced synthesis have been developed. Significant rate-enhancement and yield increase were observed. 3,4-Dihydro-2H-pyran-2-carboxaldehyde was obtained in 91% yield under microwave irradiation for 5 minutes instead of 39% yield by reacting at 190 °C for 40 min or at 160 °C for 4 hr.     

新型菊酯类化合物的组合合成及杀菌活性

新型菊酯类化合物的组合合成及杀菌活性;菊酯化合物库     

High‐Output Polymer Screening: Exploiting Combinatorial Chemistry and Data Mining Tools in Catalyst and Polymer Development

High‐output polymer screening (HOPS) combines automated polymerization with online reaction monitoring, rapid polymer characterization and novel fingerprint technology useful in polymer preparation as well as polymer processing and polymer additive development. Originally, HOPS was introduced to develop polymerization catalysts and polyolefin materials more effectively. In comparison to conventional high‐throughput screening, focusing on ultrahigh speed of catalyst screening using arrays of miniaturized reactors, output‐oriented, process‐relevant HOPS is aiming at generating and exploiting high information density (useful information/experiment). Catalyst systems for olefin polymerization are evaluated in automated workstations with multiparallel as well as semi‐ and fully automated, upgraded lab reactors. Automated polymerizations under standardized conditions afford large families of well‐characterized polymers which serve as calibration samples for data analysis. Data analysis, using multivariate calibration, is the key to basic correlations between spectroscopic information and catalyst and polymer properties as well as reaction parameters and processing conditions. IR spectroscopic fingerprints are used to measure chemical copolymer composition, density, molecular weight as well as thermal and even mechanical properties. This fingerprint technology can be applied in online quality control and facilitates transfer from lab results into pilot and production plants. Fingerprint methods are important components of rapid online analysis and can reduce the need for time‐ and money‐consuming polymer testing.

Fingerprint technology combines spectroscopic analysis by means of “cheap” spectrometers with multivariate calibration.     

组合化学法在筛选真空紫外荧光材料中的应用

综述了近年来组合化学法在筛选新型真空紫外荧光材料研究方面取得的进展, 包括组合材料库的并行合成和高通量表征技术, 并重点介绍了组合材料库的设计艺术, 最后列举了组合化学法筛选真空紫外荧光材料体系研究的实例及结果.     

Towards an Integrated Platform for Combinatorial Library Synthesis and Screening

JPC – Journal of Planar Chromatography – Modern TLC - Combined technology for the synthesis, separation, screening, and analysis of combinatorial libraries is described. The technique...     

一种新手性配体的合成及其锇配合物的催化作用

以1,4-二氯-2,3-二氮杂萘为原料,经两步反应合成了一种新的金鸡纳生物碱衍生物手性配体2,其结构经1H NMR,13C NMR和MS表征。OsO4-2用于催化烯烃的不对称双羟化反应,化学产率91%~94%,e.e.值93%~99%;用于催化烯烃的不对称氨羟化反应,收率45%~63%,e.e.值83%~95%。     

New Efficient Multicomponent Reactions with C-C Coupling for Combinatorial Application in Liquid and on Solid Phase

Up to nine C-C bonds are formed selectively from up to seven components starting from an alkene, a haloarene, and a dienophile [Eq. (1)]. A comparison of liquid- and solid-phase reactions reveals a surprising superiority of the solid-phase reaction.     

计算化学探索性实验设计：气体在固体表面的吸附现象及其对催化作用的影响

结合计算化学方法,介绍了一个面向高年级本科生的物理化学实验。本实验运用Materials Studio软件,通过量子化学方法研究H₂在Ni表面的物理和化学吸附现象,以及覆盖度和催化剂对于H₂解离的影响。通过本实验,可以使学生初步掌握借助计算化学手段获得反应活化能、搜索过渡态的思路和方法,有助于学生从原子层面上理解气体在固体表面的吸附现象。