一类酶反应底和的光化学荧光研究

研究了对位取代酚在酶反应底物的光化学荧光反应机理，指出光子不仅可以取代过氧化物酶，而且可以取代氧化剂（Ｈ２Ｏ２）。用于测定多处酶反应底物，结果满意。     

线型异核三金属M－E－M（M＝Mo，W；E＝Hg，Zn）化合物的研究──［η~5－RC_5H_4（CO）_3M］_2Zn（M＝Mo，W；R＝CO_2Me，CO_2Et）的合成、性质及结构

研究了含汞三金属化合物［η_５－ＲＣ_５Ｈ_４（ＣＯ）_３Ｍ］_２Ｈｇ（Ｍ＝Ｍｏ，Ｗ；Ｒ＝Ｍｅ，Ｅｔ，ＣＯ_２Ｍｅ，ＣＯ_２Ｅｔ）与锌粉的置换反应，发现当取代基Ｒ为给电子的Ｍｅ和Ｅｔ时底物不发生反应，而取代基Ｒ为拉电子的ＣＯ_２Ｍｅ和ＣＯ_２Ｅｔ时，则底物中的汞可被锌置换，生成带有机官能团的三金属化合物［η_５－ＲＣ_５Ｈ_４（ＣＯ）_３Ｍ］_２Ｚｎ；另外，还发现Ｒ为ＣＯ_２Ｅｔ，Ｍ为Ｍｏ的产物［η_５－ＲＣ_５Ｈ_４（ＣＯ）_３Ｍ］_２Ｚｎ可在室温下被分解为相应的氯代物η_５－ＥｔＯ_２ＣＣ_５Ｈ_４ＭｏＣｌ．     

μ－氧代双锰（Ⅲ）卟啉氧化反应及取代基效应研究

用紫外－可见光谱对氧化剂ＰｈＩＯ、Ｈ_２Ｏ_２和空气对μ－氧代双四苯基卟吩合锰（［ＴＰＰ·Ｍｎ（Ⅲ）］_２Ｏ）的氧化过程进行监测，揭示了［ＴＰＰＭｎ（Ⅲ）］_２Ｏ在不同氧化剂作用下具有不同的反应过程。研究了８种取代μ－氧双四苯基卟吩合锰｛［ＴＸＰＰＭｎ（Ⅲ）］_２Ｏ，Ｘ＝ｐ－（ｉ－Ｐｒ），ｐ－ＣＨ_３，ｐ－Ｃｌ，ｐ－Ｆ，ｐ－ＯＣＨ_３，Ｈ，ｍ－Ｃｌ，ｏ－Ｃｌ｝与Ｈ_２Ｏ_２反应中的取代基效应和溶剂效应。结果表明：上述反应为卟啉环上的吸电子基所促进；且反应速率随着反应溶剂的亲核性能的增加而增加。     

吲哚酚显色底物的合成及其在微生物检测中的应用研究进展

吲哚酚显色底物是由作为产色原的吲哚酚或其取代物与酶底物间接缩合而成,其合成主要包括中间体乙酸1-乙酰基-吲哚-3-基酯的合成及其与酶底物的衍生物缩合两部分。中间体可以通过以取代苯胺、邻氨基苯甲酸、邻氯苯甲酸等为起始物合成,而其再与酶底物的衍生物如乙酰溴代糖、酰卤、三氯氧磷、氯磺酸等反应可得到相应的各种显色底物。吲哚酚显色底物应用于微生物检测,依据特异性酶与相应底物的特异性反应,一般通过显色培养基技术来实现,不同的显色底物针对的酶及其应用于检测的微生物会有所不同。     

线型异核三金属M—E—M（M=Mo,W;E=Hg,Zn）化合物的研究…

研究了含汞三金属化合物「η－ＲＣ５Ｈ４（ＣＯ）３Ｍ２「Ｈｇ（Ｍ＝Ｍｏ，Ｗ；Ｒ＝Ｍｅ，Ｅｔ，ＣＯ２Ｍｅ，ＣＯ２Ｅｔ）与锌粉的置换反应，发现当取代基Ｒ为给电子的Ｍｅ和Ｅｔ时底物不发生反应，而取代基Ｒ为拉电子的ＣＯ２Ｍｅ和ＣＯ２Ｅｔ时，则底物中的汞可被锌置我。     

长链烷氧基取代金属卟啉／H2O2体系催化烯烃环氧化反应研究

长链烷氧基取代金属卟啉／Ｈ_２Ｏ_２体系催化烯烃环氧化反应研究肖友发，游劲松，余孝其，虞小华，蓝仲薇（四川大学化学系成都６１００６４）关键词长链烷氧基金属卟啉，过氧化氢，烯烃，环氧化反应具有疏水结合部位的金属卟啉，如甾体一金属卟啉［１］、环糊精一金属卟...     

（四甲基二硅撑）双（3－三甲硅基环戊二烯基）－四羰基二铁的反应性

标题化合物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η￣５－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２］_２／（μ－ＣＯ）_２（Ａ）分子中的Ｆｅ－Ｆｅ键被钠汞齐还原断裂，生成相应的双铁负离子，分别与ＭｅＣＯＣｌ、ＰｈＣＯＣｌ、ＰｈＣＨ_２Ｃｌ、ＣｌＣＨ_２ＣＯＯＣ_２Ｈ_５和Ｐｈ_３ＳｎＣｌ进行亲核取代反应，生成在铁原子上引入相应取代基的产物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η￣５－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２Ｒ］_２（Ｒ：ＭｅＣＯ（１），ＰｈＣＯ（２），ＰｈＣＨ_２（３），ＣＨ_２ＣＯＯＣ_２Ｈ_５（４），Ｐｈ_３Ｓｎ（５），Ｉ（６））。Ａ在氯仿中与碘反应，得到Ｆｅ－Ｆｅ断裂的双铁碘化物，但在苯中与过量碘反应，则得到Ｆｅ－Ｉ－Ｆｅ桥联的离子型化合物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η￣５－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２］_２Ｉ·Ｉ（７）。化合物６的晶体和分子结构经Ｘ射线衍射测定，６属单斜晶系，Ｐ２１／ｃ空间群，ａ＝１．７２１７（４）ｎｍ，ｂ＝０．７７５３（２）ｎｍ，Ｃ＝１．３６２９（７）ｎｍ，β＝１０３．８０（３）°，Ｖ＝１．７６７（２）ｎｍ３，Ｚ＝４，Ｄｃ＝１．６２９９·ｃｍ－１，最终偏差因子Ｒ＝０．０５４。     

双核金属酞菁类化合物催化脱硫机理研究Ⅵ──电子转移机制和催化脱硫机理

提出了双核金属酞菁类化合物催化Ｈ_２Ｓ液相氧化反应的催化电池电子转移机制，即借助于催化剂分子自身歧化所形成的催化电池Ｍ（Ⅰ）Ｐｃ－ＰｃＭ（Ⅲ）实现底物（ＨＳ~－）与分子氧间的电子转移，其反应过程为阴极反应：Ｏ_２＋Ｍ（Ⅰ）Ｐｃ→Ｏ_２~－＋Ｍ（Ⅱ）Ｐｃ，阳极反应：ＨＳ－＋Ｍ（Ⅲ）Ｐｃ→ＨＳ·＋Ｍ（Ⅱ）Ｐｃ。这一电子转移过程也是决定整个反应的控制步骤，从而导致催化反应按自由基历程进行。     

漆树漆酶的催化氧化作用 (ⅹⅢ)──Fe~(2+)离子对漆酶催化氧化反应的影响()

以５,６－二溴－２,３－二氰基氢醌为底物,在ｐＨ４．５０条件下,用分光光度法考察了ＦｅＳＯ４对漆树漆酶催化氧化反应的影响．结果表明,在本文实验条件下ＳＯ２－４离子对酶促反应的影响基本可以忽略,而Ｆｅ２＋离子对漆酶的催化氧化反应则有明显的竞争性抑制作用．研究证实,Ｆｅ２＋离子的抑制作用是通过它还原酶促反应的产物半醌自由基阴离子来实现的     

芳基肟胺菊酯类化合物和1，2，4－噁二唑衍生物的合成及其生物活性研究

芳基肟胺化合物与取代环丙烷羧酸酰氯在Ｅｔ_３Ｎ作用下室温反应得到芳基肟胺菊酯类化合物，在甲苯中回流反应则得到含取代环丙烷基的１，２，４－　二唑衍生物。前者在甲苯中回流，ＨＯＡｃ作催化剂时发生环化反应也生成１，２，４－　二唑衍生物．初步生物活性测试表明这些化合物具有的杀菌和除草活性．     

Directed evolution of protease beacons that enable sensitive detection of endogenous MT1-MMP activity in tumor cell lines

Directed evolution was applied to identify peptide substrates with enhanced hydrolysis rates by MT1-MMP suitable for protease beacon development. Screening of a random pentapeptide library, using two-color CLiPS, yielded several substrates identical to motifs in distinct collagens that shared the consensus sequence P-x-G↓L. To identify substrates with enhanced cleavage rates, a second-generation decapeptide library incorporating the consensus was screened under stringent conditions, which resulted in a MxPLG↓(M)/(L)M(G)/(A)R consensus motif. These substrates are hydrolyzed by human-MT1-MMP up to six times faster than reported peptide substrates and are stable in plasma. Finally, incubation of soluble protease beacons incorporating the optimized substrates, but not previous substrates, enabled direct detection of endogenous MT1-MMP activity of human-fibrosarcoma (HT-1080) cells. Extended substrate libraries coupled with CLiPS should be useful to generate more effective activity probes for a variety of proteolytic enzymes.     

Catalytic transfer hydrogenation reactions of PEG-bound succinyl esters

Various substrates bound to polyethylene glycol (PEG) through succinyl ester linkages were cleaved under catalytic transfer hydrogenation conditions. The substrates with unsaturated functions also underwent hydrogenation. The protocol was found to be suitable for substrates having acid and base labile functional groups.     

Bio-orthogonal affinity purification of direct kinase substrates

Protein phosphorylation is a major mechanism of post-translational protein modification used to control cellular signaling. A challenge in phosphoproteomics is to identify the direct substrates of each protein kinase. Herein, we describe a chemical strategy for delivery of a bio-orthogonal affinity tag to the substrates of an individual protein kinase. The kinase of interest is engineered to transfer a phosphorothioate moiety to phosphoacceptor hydroxyl groups on direct substrates. In a second nonenzymatic step, the introduced phosphorothioate is alkylated with p-nitrobenzylmesylate (PNBM). Antibodies directed against the alkylated phosphorothioate epitope recognize these labeled substrates, but not alkylation products of other cellular nucleophiles. This strategy is demonstrated with Cdk1/cyclinB substrates using ELISA, western blotting, and immunoprecipitation in the context of whole cell lysates.     

Surface enhanced Raman optical activity of molecules on orientationally averaged substrates: theory of electromagnetic effects

We present a model for electromagnetic enhancements in surface enhanced Raman optical activity (SEROA) spectroscopy. The model extends previous treatments of SEROA to substrates, such as metal nanoparticles in solution, that are orientationally averaged with respect to the laboratory frame. Our theoretical treatment combines analytical expressions for unenhanced Raman optical activity with molecular polarizability tensors that are dressed by the substrate's electromagnetic enhancements. We evaluate enhancements from model substrates to determine preliminary scaling laws and selection rules for SEROA. We find that dipolar substrates enhance Raman optical activity (ROA) scattering less than Raman scattering. Evanescent gradient contributions to orientationally averaged ROA scale to first or higher orders in the gradient of the incident plane-wave field. These evanescent gradient contributions may be large for substrates with quadrupolar responses to the plane-wave field gradient. Some substrates may also show a ROA contribution that depends only on the molecular electric dipole-electric dipole polarizability. These conclusions are illustrated via numerical calculations of surface enhanced Raman and ROA spectra from (R)-(-)-bromochlorofluoromethane on various model substrates.     

Hydrogen-bond directed palladium-catalyzed allylic substitution of cyclic substrates

The regioselectivity of the Pd-catalyzed allylic substitution of cyclic substrates possessing an adjacent amide functional group was investigated. With imide-like nucleophiles, six-membered ring substrates were found to proceed with a high level of regiodirection whereas hydrogen-bond directed addition was not a significant factor in the five-membered ring substrates.     

Evaporation of droplets of silver nanoparticle dispersions on metal surfaces

The formation of ring-shaped deposits during the evaporation of droplets of silver nanoparticle dispersions on aluminum, copper, and nickel substrates has been studied, and the geometric characteristics and conductivity of the deposits have been determined. The formation process of the deposits on the above substrates has been shown to exhibit some peculiarities to compare with that on hydrophilic glass substrates. These peculiarities lead to substantial differences in the geometric parameters and structure of the deposits formed on substrates of different natures. Therewith, the qualitative regularities of variations in the geometric parameters and conductivity of the deposits with the size (numerical concentration) of silver nanoparticles remain preserved.     

Application of modified Pictet-Spengler reaction for the synthesis of thiazolo- and pyrazolo-quinolines

Two new thiazole and pyrazole-based arylamine substrate have been used for the Pictet-Spengler reaction. This is in contrast to the traditionally used indole/imidazole-based aliphatic amine substrates that has remained in use for the last ∼100 years. The condensation of both the substrates with a variety of aldehydes in the presence of 2% TFA-DCM at 0° for 30 min or pTsOH in toluene at reflux led to the synthesis of thiazoloquinolines and pyrazoloquinolines, respectively. Unlike aliphatic amine substrates, our substrates readily underwent Pictet-Spengler cyclization even with aldehydes having electron donating group. The studies are based on a new concept proposed by us that arylamines linked to an activated heterocyclic ring can lead to a variety of second-generation substrates for the Pictet-Spengler cyclization. Our studies open up new avenues for the application of Pictet-Spengler reaction beyond syntheses of the tetrahydroisoquinolines and tetrahydro-β-carbolines.     

Selective photocatalytic transformations on microporous titanosilicate ETS-10 driven by size and polarity of molecules

Photocatalytic activity of microporous titanosilicate ETS-10 has been studied in water. The photoactivated ETS-10 shows catalytic activity driven by size and polarity of substrates. ETS-10 efficiently catalyzes a conversion of substrates with a size larger than the pore diameter of ETS-10. In contrast, the reactivity of small substrates depends strongly on substrate polarity; less polar substrates show higher reactivity on ETS-10. Electron spin resonance analysis reveals that large substrates or less polar substrates scarcely diffuse inside the highly polarized micropores of ETS-10 and, hence, react efficiently with hydroxyl radicals (*OH) formed on titanol (Ti-OH) groups exposed on the external surface of ETS-10. In contrast, small polar substrates diffuse easily inside the micropores of ETS-10 and scarcely react with *OH, resulting in low reactivity. The photocatalytic activity of ETS-10 is successfully applicable to selective transformations of large reactants or less polar reactants to small polar products, enabling highly selective dehalogenation and hydroxylation of aromatics.     

Oxidative rearrangement of tertiary allylic alcohols employing oxoammonium salts

Practical and highly efficient methods for oxidative rearrangement of tertiary allylic alcohols to beta-substituted alpha,beta-unsaturated carbonyl compounds employing oxoammonium salts are described. The methods developed are applicable to acyclic substrates as well as medium membered ring substrates and macrocyclic substrates. The counteranion of the oxoammonium salt plays crucial roles on this oxidative rearrangement.     

The preparation of perfluoroalkenyl allenes (trienes) and pentafluorophenyl allenes

Trifluorovinyl- and (Z)-pentafluoropropenylcopper reagents readily react with propargylic halides or tosylates. With primary propargylic substrates, the major product is the alkyne. With secondary propargylic substrates, mixtures of alkyne/allene are obtained; the allene product is the major product. With tertiary propargylic substrates, the allene is regiospecifically and stereospecifically formed in good isolated yields. With pentafluorophenyl copper and primary propargylic substrates, the major product is pentafluorobenzene. With secondary and tertiary propargylic substrates, the allene is regiospecifically formed in good isolated yields.