Nafion修饰金膜玻碳电极溶出伏安法测定痕量Se（Ⅳ）的研究

提出了Ｎａｆｉｏｎ修饰膜玻碳电极测定痕量硒的新方法。在０．１ｍｏｌ．Ｌ＾－１硫酸和０．０１．Ｌ＾－１硝酸钠的介质中，Ｓｅ（Ⅳ）浓度在５．０＊１０＾－１０－２．５＊１０＾－８ｍｏｌ．Ｌ＾－１范围与二次导数峰电流呈良好线性关系，测定下限为５．０＊１０＾－１０ｍｏｌ．Ｌ＾－１。     

头孢拉定的电化学行为

头孢拉定在ＮｏＯＨ溶液中降解后，于０．３ｍｏｌ／Ｌ ＮａＯＨ底液中有一灵敏的导数还原峰。电峰位为－０．８４Ｖ左右，峰电流ｉｐ与头孢拉定浓度在２．０＊１０＾－８－５．０＊１０＾Ｔ－６ｍｏｌ／Ｌ范围内呈线性关系，检测限为５．０＊１０＾－９ｍｏｌ／Ｌ。     

博莱霉素A5的示波极谱行为及测定

在０．０５ｍｏｌ／Ｌ Ｈ２ＳＯ４支持电解质中，博莱霉素Ａ５出现二个示波极谱导数还原峰，峰电位Ｅｐ１＝－０．８２Ｖ和Ｅｐ２＝－１．０８Ｖ（ｖｓ．ＳＣＥ）。峰电流ｉｐ１比峰电流ｉｐ２小得多。ｉｐ２与博莱霉素Ａ５的浓度在５．０＊１０＾－８－４．０＊１０＾－６ｍｏｌ／Ｌ范围内呈线性关系；检出限为１．０＊１０＾－８用于老鼠血样中博莱霉素Ａ５含量的测定，得到满意的结果，对第二个峰的电化学行为作了初步探讨。     

鲁米诺—双氧水—铬（Ⅲ）化学发光体系测定化探样品中痕量砷

用鲁米诺－双氧水－铬（Ⅲ）化学发光体系结合巯基棉对Ａｓ（Ⅲ）的富集分离，建立了快速的测定化探样品中痕量砷的新方法，检测线性范围为１．０＊１０＾－４－１．０＊１０＾１ｍｇ／Ｌ，检出限为３．４＊１０＾－５ｍｇ／Ｌ。用于实际化探样吕测定，相对标准偏差为５．５＾－９．０％。     

脱氧核糖核酸（DNA）的极谱伏安行为研究

研究了脱氧核糖核酸的极谱伏安行为，在０．１ｍｏｌ．Ｌ＾－１ＮＨ４Ｃｌ溶液中ＤＮＡ产生一良好的极谱峰，峰电位Ｅｐ＝－１．６５Ｖ（ｖｓ．Ａｇ／ＡｇＣｌ），且峰电流ｉｐ与ＤＮＡ的浓度在４．５＊１０＾－５－３．７＊１０＾－４ｍｏｌ．ＬＯ＾－１范围内呈线性关系，可望用于ＤＮＡ的定量分析。     

头孢噻肟钠降解产物在银微电极上示差脉冲阴极溶出伏安法的测定

基于包噻肟钠（ＣＴＸ）在０．１０ｍｏｌ／Ｌ ＮａＯＨ溶液中水浴降解产物含有巯基（－ＳＨ），在ＰＨ４．５ＮａＡｃ－ＨＡｃ介质中，于奶微电极上产生－灵敏的吸附伏安还原峰，峰电位Ｅｐ＝－０．５５Ｖ（ｖｓ．ＳＣＥ）。示差脉冲溶出峰电流与ＣＴＸ浓度在１．０＊１０＾－７－１．０＊１０＾－５ｍｏｌ／Ｌ范围内呈线性关系，方法可应用于模拟样品ＣＴＸ的检测，令人满意。     

镉-茜素紫-邻二氮菲体系的极谱行为及应用

用线性扫描示波极谱法研究了镉（Ⅱ）－茜素紫－邻二氮菲体系的极谱行为，发现在含有０．１ｍｏｌ／Ｌ ＫＣｌ、ｐＨ＝２．８５的ＨＡｃ的溶液中，镉（Ⅱ）－茜素紫－邻二氮菲体系产生－灵敏的极谱吸附波，共峰电位为－０．６４Ｖ（ｖｓ．ＳＣＥ），峰电流与镉（Ⅱ）的浓度在５．０＊１０＾－８－１．０＊１０＾－６ｍｏｌ／Ｌ的范围内呈一性关系；检出限为３．０＊１０＾－８ｍｏｌ／Ｌ。研究了电极反应机理，并用建立的方法成功地测定了废水样中的镉。     

筛选免疫药物的单扫描示波极谱法研究

用示波极谱研究了溶血素的溶血活性，在１／１５ｍｏｌＬＮａＨＰＯ４－１．１５ｍｏｌ．ＬＫＨ２ＰＯ（ｐＨ＝７．４）底液中活性溶血素有一灵敏的极谱阴极波，峰电位为－１．８２Ｖ，峰高与溶血素活性在６．０＊１０＾－６－５。３＊１０＾－５ｕｎｉｔ．ｍＬ和５．３＊１０＾－５－２。０＊１０＾－３ｕｎｉｔ／ｍＬ范围内呈线性关系，根据不同药物对抗血清中溶血清形成的不同影响，建立了极谱法筛选免疫药物的新方法。本法简单，     

流动注射化学发光抑制法测定抗坏血酸

基于抗坏血酸对Ｌｕｍｉｎｏｌ－ＫＩＯ４－Ｈ２Ｏ２体系化学发光反应的抑制作用,建立了化学发光抑制快速测定抗坏血酸的新方法。该方法线性范围为１．０＊１０＾－７－１．０＊１０＾－５ｍｏｌ／Ｌ,检出限为６．０＊１０＾－８ｍｏｌ／Ｌ,对８．０＊１０＾－７ｍｏｌ／Ｌ抗坏血酸１１次平行测定的相对标准偏差为１．０％。用于维生素Ｃ片剂及注射液中抗坏血酸含量的测定,结果令人满意。     

流动注射化学发光传感器测定抗坏血酸

基于抗坏血酸抑制ＫＭｎＯ４－鲁米诺体系化光反应这一效应，设计出一种简便，快速，灵敏度高的消耗型化学发光抗坏血酸传感器。该传感器线性响应范围为１．０＊１０＾－５－４．０＊１０＾－３ｇ／Ｌ；相对标准偏差为２．３％（１．０＊１０＾－４ｇ／Ｌ，ｎ＝１１）；     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.