金属卟啉化合物及其对烷烃的仿生催化氧化

综述;金属卟啉化合物及其对烷烃的仿生催化氧化     

金属卟啉催化烷烃选择性氧化反应的研究进展

金属卟啉作为一种仿生催化剂,能够实现在温和条件下对分子氧的催化活化,在催化烷烃氧化反应中显现出巨大的潜力.本文总结了金属卟啉结构对烷烃选择性氧化结果的影响,并介绍了近期金属卟啉催化剂应用于烷烃氧化反应的研究进展,最后探讨了金属卟啉催化剂在催化烷烃选择性氧化反应中存在的问题及发展前景.     

μ-氧代双锰卟啉催化下空气高选择氧化乙苯

金属卟啉能够在温和条件下催化烃类的部分氧化,且有较好的选择性因此,金属卟啉的仿生催化研究不仅具有重大的理论意义,亦有广阔的应用前景,现已成为仿生催化领域中人们极感兴趣的工作,但是,金属卟啉化合物催化领域中人们极感举的工作,但是,金属卟啉化合物催化烃类氧化时,一般须使用诸如PhIO、NaClO、H2O2这样的单氧原子供体作氧化剂,或使用诸如锌粉、Vc等还原剂加分子氧体系,从实际应用来看,单独使用分子氧为氧化剂用于金属卟啉催化烃类氧化是最具诱惑力的。然而,在这方面的研究报导仅见于多卤代卟啉,我们在探索单独用空气作用氧化剂进行金属卟啉仿生催化时发现,象乙苯这样含有相对较为活泼的C－H键的分子,在μ－氧化双锰卟啉（[TPPMn]2O)的催化下,亦能够直接被分子氧氧化,本工作考察了各种因素对该反应的影响。     

水溶性金属卟啉应用于催化反应的研究进展

综述了水溶性金属卟啉作为催化剂应用于均相或非均相的催化反应的研究进展,重点介绍了水溶性金属卟啉在水或水与有机溶剂混合介质中催化底物氧化反应的催化性能,其中包括烷烃的羟基化,烯烃的环氧化,含氧、含硫及含氮化合物的氧化反应.另外水溶性金属卟啉还可用于催化Suzuki-Miyaura反应、氧化偶联反应、C=C氧化断裂反应等.水溶性金属卟啉催化剂具有水溶性、催化效率高、反应条件温和等优点,因此将在催化反应特别是氧化反应中得到更广泛的应用.     

仿生催化及其在烃类氧化中的应用

从叶绿素及血红素的结构出发,综述金属卟啉仿生催化的特点;重点介绍仿生催化的概念,仿生催化氧化过程与技术以及仿生催化氧化在工业上的应用;总结仿生催化以及该技术的发展现状和前景。     

金属卟啉催化下环己烷羟基化反应的Hammett关系

合成了４０个卟啉环上具有不同取代基的单铁、锰卟啉和μ－氧桥连双铁、锰卟啉、研究了这些金属卟啉模拟细胞色素Ｐ－４５０单充氧酶在温和条件下催化环己烷羟基化的反应。首次用线性自由能关系对金属卟啉仿生催化反应和金属卟啉自氧人反应进行相关分析，获得一 些新的结果和规律。在此基础上，对金属卟啉仿生催化反应的可能机理进行了探讨。     

诱捕在沸石超笼内的金属卟啉的催化性能

诱捕在沸石超笼内的金属卟啉的催化性能＊王杏乔高爽曹昌盛于连香曹锡章（吉林大学化学系，长春１３００２３）关键词诱捕的金属卟啉，分子筛，苯乙烯，对甲酚，氧化众所周知，金属卟啉是一种共轭的大环化合物，这种化合物具有特殊的性能，尤其在氧化－还原反应中的催化性...     

金属卟啉催化下环己烷羟基化反应中的Hammett关系

合成了40个卟啉环上具有不同取代基的单铁、锰卟啉和u-氧桥连双铁、锰卟啉,研究了这些金属卟啉模拟细胞色素P－450单充氧酶在温和条件下催化环己烷羟基化的反应.首次用线性自由能关系对金属卟啉仿生催化反应和金属卟啉自氧化反应进行相关分析,获得一些新的结果和规律.在此基础上,对金属卟啉仿生催化反应的可能机理进行了探讨.     

金属卟啉类模拟酶催化剂研究

对金属卟啉化合物在催化氧化反应中的应用和机理方面的最新研究成果进行了详细的阐述,并概述了量化计算方法在金属卟啉分子设计、结构及催化活性等方面的应用.也介绍了本课题组在上述领域的最新研究成果.预测了金属卟啉化合物在催化领域的应用前景.     

金属酞菁与高价金属盐或氧化物在乙苯液相催化氧化反应中的协同效应

金属络合物催化饱和烷烃的选择性催化氧化一直是有机合成中具有挑战性的课题之一.饱和烷烃的催化氧化可采用各种氧源,如PhIO、H2O2、有机过氧化物或次氯酸盐等[1,2],然而采用分子氧为氧源对烃类化合物进行选择性催化氧化一直是人们致力于解决的目标.利用分子氧为氧源实现饱和烷烃的选择性催化氧化大致可分为两条路线:(1)在共还原剂(H2,醛,抗坏血酸)存在下利用原位产生的氧化剂的催化氧化[3,4];(2)金属卟啉[5]、杂多酸[6]及其它催化剂对饱和烷烃的直接催化氧化.路线(1)需要消耗大量的共还原剂,实际上是对分子氧的间接利用,不具有明显的实…     

Theoretical studies and industrial applications of oxidative activation of inert C-H bond by metalloporphyrin-based biomimetic catalysis

High costs and low catalytic efficiency of metalloporphyrins, which are an analogue of cytochrome P450 enzyme, are the bot-tlenecks in the industrialization of biomimetic hydrocarbon oxidation reactions. The basic principle and research technique of physical organic chemistry were applied to the process of biomimetic oxidation of hydrocarbon catalyzed by metalloporphyrins. This biomimetic technology could be adapted to bulk chemicals production by developing the new methods for efficient scale-up synthesis of metalloporphyrins, new pathways for molecular oxygen activation on an industrial scale and new approaches to elevate the catalytic efficiency of metalloporphyrins. This review mainly focuses on research carried out in our group.     

金属次卟啉二甲酯对空气氧化环己烷的催化作用

在无任何外加溶剂及共还原剂的条件下, 将金属次卟啉二甲酯应用于催化空气氧化环己烷的氧化反应. 结果表明, 金属次卟啉二甲酯能够很好地催化环己烷的氧化反应, 与简单的金属四苯基卟啉相比, 金属次卟啉二甲酯催化剂具有更高的催化活性. 进而研究了络合金属对其催化性能的影响.     

金属卟啉自氧化反应研究

金属卟啉能在温和条件下催化PhIO、H_2O_2和NaClO等氧化剂对烷烃和烯烃的单充氧反应,但在这些氧化剂存在下,金属卟啉本身存在自毁灭现象而失去催化活性,关于金属卟啉的自毁灭现象,尚无文献详细报道,我们发现,这一现象实际上是金属卟啉在氧化剂作用下发生的自氧化反应,为了系统地研究并控制金属卟啉的自氧化反应,我们合成了9种不同结构的金属卟啉(图1),从动力学上对它们的自氧化反应进行了考察,研究发现,铁和铬卟琳的自氧化反应在动力学上为二级反应,锰卟啉为一级反应;卟啉环上的取代基,无论是吸电子基还是供电子基都使反应速度加快;但在反应体系中加入中性有机配体,能抑制金属卟啉的自氧化速度,氧化剂的能力越强,反应速度越快;溶剂的极性越小,反应速度越慢。     

Cyclohexene Promoted Efficient Biomimetic Oxidation of Alcohols to Carbonyl Compounds Catalyzed by Manganese Porphyrin under Mild Conditions

Selective oxidation of alcohols to corresponding carbonyl compounds is one of the most important processes both in academic and application research. As a kind of biomimetic catalyst, metalloporphyrins‐catalyzed aerobic oxidation of alcohols with aldehyde as hydrogen donator is gathering much attention. However, using olefins as another kind hydrogen donator for aerobic oxidation of alcohols has not been reported. In this study, a system comprising managenese porphyrin and cyclohexene for biomimetic aerobic oxidation of alcohols to carbonyl compounds was developed. The catalytic system exhibited excellent catalytic performance and selectivity towards the corresponding products for most primary and secondary alcohols under mild conditions. Based on the results obtained from experiments as well as in situ EPR (electron paramagnetic resonance) and UV‐vis spectroscopy, the role of cyclohexene was demonstrated.     

Study of the catalytic behavior of montmorillonite/iron(III) and Mn(III) cationic porphyrins

Two samples of montmorillonite (one of Brazilian origin, BNC1 clay, and the other STX-1, supplied by the Clay Mineral Society Repository (University of Missouri, USA) were allowed to react with biomimetic metalloporphyrins of Fe(III) and Mn(III) in cationic form. The compounds were characterized by several techniques, showing that the metalloporphyrins molecules were adsorbed at the surface of the clay platelet crystals. The catalytic activities of the intercalated complexes for the oxidation of alkane were dependent upon the concentration of the porphyrin immobilized in the clay and factors such as the metal ion species in the porphyrins, choice of solvent, and concentration of the iodosylbenzene oxidant. Good selectivity to cyclohexanol instead of cyclohexanone was observed for the catalytic oxidation of cyclohexane by iodosylbenzene.     

Oxidation of caffeine with hydrogen peroxide catalyzed by metalloporphyrins

The biomimetic oxidation of caffeine with hydrogen peroxide using metalloporphyrins as catalysts, which are known to be good biomimetic models of cytochrome P450 enzymes, is investigated. The two manganese porphyrins tested, chloro[5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrinato]manganese(III), [Mn(TDCPP)Cl], and chloro [5,10,15,20-tetrakis(pentafluorophenyl)porphyrinato]manganese(III), [Mn(TPFPP)Cl], afford high conversions of caffeine for all substrate/catalyst molar ratios. Selectivity was found to be dependent on the catalyst employed, and a new spiro racemic compound is described and fully characterized in the solid state from X-ray diffraction studies.     

高分子多糖载体对四苯基金属卟啉催化性能影响

在壳聚糖四苯基金属卟啉中, 氨基或羟基可能对金属卟啉的稳定性和催化活性起重要作用. 为探索这两类基团的作用效果差异, 并调查具有类似壳聚糖结构的纤维素作为载体, 对金属卟啉的保护以及羟基的协助催化作用, 制备了纤维素四苯基铁、钴和锰卟啉. 研究了纤维素四苯基铁、钴和锰卟啉催化空气氧化环己烷的能力, 并与相应的壳聚糖金属卟啉比较. 在418 K和0.8 MPa的空气压力下, 纤维素四苯基铁(钴或锰)卟啉均只能作一次性催化而耗尽; 所获得的醇酮选择性均低于相应的壳聚糖四苯基金属卟啉. 研究结果表明: 纤维素对四苯基铁、钴和锰卟啉没有明显的保护作用, 羟基对其催化环己基过氧化氢的协助分解作用也比较小. 壳聚糖对金属卟啉有很强的保护作用, 氨基有较强的协助金属卟啉催化环己基过氧化氢分解的能力, 使醇酮选择性提高.     

金属四苯基卟啉在氧化银和银胶体上的表面增强拉曼光谱研究(英文)

研究了四苯基卟啉金属配合物 (MTPP ;M =Ag ,Cu ,Pd ,Mg)和游离碱 (H2 TPP)在氧化银和银胶体中的表面增强拉曼光谱 (SERS) .在Ag2 O胶体中MTPP和H2 TPP的SERS谱与其普通拉曼谱明显不同 ,可知吸附分子在Ag2 O胶粒表面发生反应所引起 ,况且产物于 4 6 0nm附近有一强烈吸收 ,可知它含有共扼双吡咯发色团 .在OH- 修饰的银胶上也观察到类似的光谱变化 .     

金属卟啉催化环己烷羟基化反应中环己酮的形成机理研究

单金属卟啉和双金属卟啉催化下PhIO常温氧化环己烷的羟基化反应中金属卟啉结构和反应溶剂、反应温度、反应时间等环境因素对产物酮含量及酮形成反应动力学的影响进行了系统研究, 并与金属卟啉催化下PhIO氧化环己醇的反应进行了对比, 提出了金属卟啉催化下环己烷羟基化反应中产物酮的形成机理。     

Biomimetic modeling of oxidative drug metabolism

The prediction of drug metabolism is an important task in drug development. Besides well-established in vitro and in vivo methods using biological matrices, several biomimetic models have been developed. This review summarizes three different nonenzymatic strategies, including metalloporphyrins as surrogates of the active centre of cytochrome P450, Fenton’s reagent, and the electrochemical oxidation of drug compounds. Although none of the systems can simulate the whole range of cytochrome P450-catalyzed reactions adequately, the biomimetic models show some advantages over standard in vitro methods. For example, metalloporpyhrin catalysts allow the synthesis of certain metabolites in sufficient amounts and with sufficient purities to permit characterization and further pharmacological and toxicological tests. The electrochemical generation of metabolites coupled on-line to liquid chromatography/mass spectrometry is a promising tool for studying reactive metabolites and can be applied in automated high-throughput screening approaches. In this paper, detailed comparisons with cytochrome P450 catalysis are drawn, advantages and disadvantages of the respective methods are revealed, and possible applications are discussed.