铁(Ⅲ)-柠檬酸盐配合物光解引发橙黄Ⅱ的脱色

介绍了金属卟啉化合物的结构、种类及其应用，综述了金属卟啉化合物对烷烃的仿生催化氧化研究进展。运用金属卟啉仿生催化空气氧化环己烷制备环己酮技术，使得停留在实验室研究水平的金属卟啉仿生催化烷烃空气氧化进入了工业化生产。     

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.     

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.     

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.     

乙酰糖基金属卟啉的合成及其对烷烃温和氧化的选择性催化作用

由吡咯和葡萄糖取代苯甲醛直接缩合制备了两种葡萄糖取代卟吩,四(邻位乙酰葡萄糖氧代苯基)卟吩和四(间位乙酰葡萄糖氧代苯基)卟吩,它们进一步金属化合成了四种葡萄糖金属卟啉,氯化四(邻位乙酰葡萄糖氧代苯基)卟吩合铁、氯化四(间位乙酰葡萄糖氧代苯基)卟吩合铁、氯化四(邻位四乙酰葡萄糖氧代苯基)卟吩合锰和氯化四(间位乙酰葡萄糖氧代苯基)卟吩合锰。它们的结构由紫外-可见光谱、元素分析和核磁共振证实。研究了这些葡萄糖取代金属卟啉对亚碘酰苯常温常压下氧化异戊烷反应的选择性催化作用。研究表明,糖基金属卟啉催化异戊烷端基碳氢键的氧化,对一级碳氢键表现出专一性催化作用。非糖基金属卟啉催化异戊烷二级和三级碳氢键的氧化。与非糖基金属卟啉比较,糖基金属卟啉对烷烃羟基化反应的催化行为更接近细胞色素P-450单充氧酶。     

P(4VP-co-St)/SiO2固载的取代钴卟啉对乙苯的催化氧化性能

通过轴向配位法将不同结构的钴卟啉(CoTXPP(X=H, Cl, NO2))分别固载到接枝微粒聚(4-乙烯基吡啶-co-苯乙烯)/SiO2(P(4VP-co-St)/SiO2)上, 室温下分别制备了P(4VP-co-St)/SiO2固载的金属卟啉催化剂CoTPP-P(4VP-co-St)/SiO2, CoTClPP-P(4VP-co-St)/SiO2和CoTNPP-P(4VP-co-St)/SiO2, 利用傅立叶变换红外(FTIR)光谱和电子吸收光谱对其结构及轴配过程进行了表征. 在无溶剂、无助催化剂和还原剂的体系中, 研究对比了其催化分子氧氧化乙苯为苯乙酮的性能, 考察了不同反应条件对苯乙酮产率的影响. 研究发现, 其催化活性随着环外取代基吸电子能力的增强而提高. CoTNPP-P(4VP-co-St)/SiO2的催化活性和选择性最好, 在120 ℃常压下其催化乙苯反应12 h, 苯乙酮收率达到25.53%, 产物α-甲基苄醇的含量则极少. 与普通的催化剂不同, 在催化氧化体系中, CoTNPP-P(4VP-co-St)/SiO2存在最适宜用量, 过量的CoTNPP-P(4VP-co-St)/SiO2反而会使其催化活性降低; P(4VP-co-St)/SiO2表面CoTXPP的固载密度存在一最佳值. 此外, 固载化以后, 催化剂具有较好的重复使用性. 结果表明, 接枝微粒P(4VP-co-St)/SiO2对金属卟啉不仅有明显的保护作用, 而且能提高其稳定性.     

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.     

On a possible radical-cation mechanism of the biomimetic oxidation of the saturated hydrocarbon 1,3-dimethyladamantane in a Gif-type system containing a Fe2+ salt, picolinic acid, and pyridine

Based on an analysis of the ratio between the final products of the oxidation of 1,3-dimethyladamantane (1,3-DMA) with hydrogen peroxide under new catalytic conditions, an EPR-spectroscopic study of the 1,3-DMA radical cation under model radiation-chemical conditions, and the results of PM3 quantum-chemical calculations, a new mechanism was proposed for the biomimetic oxidation of the saturated hydrocarbon. This mechanism involves the intermediate formation of the 1,3-DMA radical cation, in which a tertiary C-H bond is selectively activated. Next, oxene (oxygen atom) is inserted into this C-H bond to form a tertiary alcohol. It was found that a comparison of the composition of final products in the oxidation of saturated hydrocarbons under conditions of a real chemical experiment with the structure and reactivity of their radical cations under model radiation-chemical conditions can be a methodologically new general technique for the analysis and prediction of the reactivity of saturated hydrocarbons under oxidative conditions.     

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.     

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。     

磁场对铁卟啉仿生催化性能的影响

在生命体中,细胞色素P－450单充氧酶辅基是具有铁Df琳结构的血红素．用金属叶琳作为细胞色素P－450单充氧酶的模型化合物探讨和研究人类生命现象一直是国内外化学仿生催化领域极为感兴趣的研究内容之一［’1．我们曾用p一氧代双铁叶琳作为细胞色素P－450单充氧酶的模型化合物,发现改变金属叶琳结构和金属原子电子自旋态将会引起金属叶琳磁性改变,而金属叶琳磁性改变会进一步导致金属叶琳仿生催化性能发生改变D”‘．我们认为,这一现象与人类和地球构成的生物圈可能有某些关联．为了考察地球磁场对人类生命现象的影响,我们进一步建立…     

四氮金属配合物仿生催化不对称氧化研究进展

非血红素四氮锰、铁配合物催化的不对称氧化反应是有机合成化学中的重要转化.这类催化剂通过模拟自然界中金属酶的结构与功能特点实现了高效的催化不对称氧化,成功地在产物分子中引入手性中心,从而构建出一类有潜在应用价值的化合物.在这些四氮配体的设计中, N,N’-二甲基-1,2-环己二胺、联吡咯和脯氨酸的衍生物是主要的二胺骨架,与吡啶、苯并咪唑侧基的不同组合可以制备出各种催化活性的仿生配合物.同时配体取代基的调整也会对不对称氧化反应产生巨大的影响.给电子基和大位阻羧酸效应显著提高了仿生催化不对称氧化反应的效率和对映选择性.我们综述了近年来非血红素锰、铁配合物催化不对称氧化反应的研究进展,主要包含N,N’-二甲基-1,2-环己二胺、联吡咯和脯氨酸的衍生物作为二胺骨架,吡啶和苯并咪唑作为侧基的四氮配合物的结构设计以及配体结构对不对称环氧化和C-H键氧化反应活性的影响,并对该领域的发展前景做出了展望.     

TEMPO-linked metalloporphyrins as efficient catalysts for selective oxidation of alcohols and sulfides

Six new TEMPO-linked porphyrins and metalloporphyrins were synthesized and they exhibited efficient catalytic activity for selective oxidation of alcohols and sulfides to the corresponding aldehydes, ketones and sulfoxides using NaOCl as oxidant.     

担载金属卟啉模拟细胞色素P-450的催化丙烯环氧化

制备了SiO2化学键合金属卟啉Mn（TPP）Cl，Mn（TDCPP）Cl的担载配合物催化剂，并与单氧给体次氯酸钠（NaClO）构造了细胞色素P－450单加氧酶模拟体系，并考察了该体系的反应性能及其影响因素．金属卟啉经化学修饰的SiO2担载之后，由于表面官能团与金属中心的轴向配位及刚性载体SiO2对金属卟啉在载体表面很好的位置分离作用，使得金属卟啉的抗氧化性及稳定性显著增加，表现出优良的催化丙烯环氧化反应性能．     

Study of enzyme models and imitation of enzyme action

This paper deals with some of the research activities in our group in recent years in the areas of artificial enzyme models with porphyrin, steroids and calixarenes as building units. Wherein two kinds of novel enzyme models of steroids-metalloporphvrin and calixarene-metalloporphyrin have been synthesized and employed as cytochrome P450 modeling. These biomimetic systems exhibited high catalytic selectivity and efficiency in oxidation of olefins (styrene, cyclohexene) and hydrocarbonds (isopropylbenzene) as well as phenol ( p-benzenedi-ol). The excellent catalytic property stems mainly from hydrophobic effect and multiple recognition sites that lead to cooperative catalysis.     

长链烷氧取代金属卟啉的合成及催化性能研究

本文报道了一类长链烷氧取代金属卟啉化合物3的合成.研究了由化合物3与表面活性剂:十二烷基三甲基溴化铵所形成的混合胶束体系作为仿细胞色素P-450加氧酶模拟物对苯乙烯环氧化的催化活性.结果表明:在胶束体系中长链烷氧取代金属卟啉的催化效率优于对称四甲苯基金属卟啉,由此证实:混合胶束中,疏水内核提供的模拟酶的疏水微环境,在苯乙烯环氧化反应中起着重要作用.     

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.     

Catalytic oxidation of organic substrates by molecular oxygen and hydrogen peroxide by multistep electron transfer--a biomimetic approach

Oxidation reactions are of fundamental importance in nature, and are key transformations in organic synthesis. The development of new processes that employ transition metals as substrate-selective catalysts and stoichiometric environmentally friendly oxidants, such as molecular oxygen or hydrogen peroxide, is one of the most important goals in oxidation chemistry. Direct oxidation of the catalyst by molecular oxygen or hydrogen peroxide is often kinetically unfavored. The use of coupled catalytic systems with electron-transfer mediators (ETMs) usually facilitates the procedures by transporting the electrons from the catalyst to the oxidant along a low-energy pathway, thereby increasing the efficiency of the oxidation and thus complementing the direct oxidation reactions. As a result of the similarities with biological systems, this can be dubbed a biomimetic approach.     

Chelating Metal Ions in a Metal-Organic Framework for Constructing a Biomimetic Catalyst Through Post-modification

Crystal engineering, as a burgeoning technology, has been widely used to construct metalloporphyrins biomimetic catalysts. Herein, a bimetallic metal-organic framework (MOF) was constructed by 4-(4-carboxyphenyl)-1,2,4-triazole ligand, Co²⁺ and Zr⁴⁺ metal ions by solvothermal reaction(named PFC-88). A N,N-chelation site was found between the two adjacent ligands in PFC-88, consequently a porphyrin-like structure was obtained through chelating Fe³⁺ in this site by post-modification, named PFC-88-Fe. The result of a single crystal X-ray technology verified that Fe ions were successfully metalated in the N,N-chelation site of PFC-88, which is assisted by the X-ray absorption near-edge structure(XANES) spectra. An o-phenylenediamine oxidation reaction was applied to assessing the catalytic activity of PFC-88-Fe, in which the absorbance increases of phenazine-2,3-diamine at λ=418 nm were recorded by absorption spectroscopy in kinetic mode, exhibiting the application potential as a biomimetic catalyst.