胡椒碱的极谱分析研究

在ｐＨ２．２的Ｂｒｉｔｔｏｎ－Ｒｏｂｉｎｓｏｎ缓冲溶液中，胡椒碱在－１．１０Ｖ（ｕｓ．ＳＣＥ）左右产生一灵敏的极谱波，导数峰电流与胡椒碱浓度在０．０５－８μｇ／ｍｌ范围内呈良好的线性关系。本法操作简便，快速，灵敏，选择性较好。用于天然胡椒果实中胡椒碱的测定，得到了满意结果。本文对极谱波性质及电极反应机理进行了研究。     

极谱络合吸附催化波测定人发中微量锗的研究

用Ｇｅ（Ⅳ）－邻苯二酚－溴酸钠极谱络合吸附催化波测定人发中微量锗，并对发样的消化处理方法进行了较详细的研究，测定结果令人满意。     

铜（II）—腺嘌呤的配位吸附波

本文对铜（Ⅱ）－腺嘌呤配位吸附波的极谱行为进行了研究。结果表明，当腺嘌呤浓度大于铜的浓度时，极谱波呈现为两电子还原配位吸附不可逆波。测定了配合物的组成及条件生成常数，对电极反应机制也进行了探讨。     

Bi（Ⅲ）—TAR络合吸附波的研究及应用

提出了铋－４－２（－噻唑偶氮）－间苯二酚络合物吸附波。试验发现，碱性条件下，络合物在单扫描示波极谱上有一个灵敏的铋还原波，峰电位－０．６０Ｖ（ｖｓ．ＳＣＥ）。方法用于纯铅中的微量铋测定，结果令人满意。     

吡哆醇的催化极谱波研究

了吡哆醇在有Ｎｉ＾２＋共存时的极谱催化波。详细研究了其极谱波的性质。在ｐＨ为６．００时磷酸氢二钠－柠檬酸缓冲液中，于０、５次微分伏安曲线上，在－１．４５伏附近观察到一灵敏极谱峰。采用０．５次微分伏安技术，可测定１０＾－８－１０＾－６ｍｏｌ／Ｌ的吡哆醇，实测了市售倒模粉中吡哆醇的含量，样品平均回收率达８５％，１０次测定的变异系数为４．６％，表明该法可用于化妆品中微量吡哆醇的测定。     

硒（IV）—四乙基碘化铵—砷（Ⅲ）体系的极谱吸附波及其应用

报道了一个测定硒的高灵敏极谱吸附波新体系。在０．７ｍｏｌ／Ｌ ＨＢｒ溶液中，Ｓｅ（Ⅳ）－（Ｃ２Ｈ５）４ＮＩ－Ａｓ（Ⅲ）体系于－０．６１Ｖ（ｖｓ．ＳＣＥ）处产生一高灵敏的极谱吸附波。峰电流与Ｓｅ（Ⅳ）浓度在０．１￣４０μｇ／Ｌ范围内呈线性关系。检出限为０．０５μｇ／Ｌ。研究了极谱波的性质。用本法测定了土壤中的全硒和有效硒，结果满意。     

铟（Ⅲ）—PMBP—Ferron极谱络合吸附波研究

在ＨＣｌ－ＮａＡｃ介质（ＰＨ２．５）中，可获得灵敏的Ｉｎ（Ⅲ）－ＰＭＢＰ－Ｆｅｒｒｏｎ极谱络合中附波，峰电位在－０．６５Ｖ处（ｖｓ．ＳＣＥ）检出限为０．０４ｎｇ／ｍＬＩｎ。峰电流与铟浓度在０．０８－２００ｎｍｇ／ｍＬ范围内呈一性关系。本法测定工业废水中的痕量铟，结果满意。本文还研究了极谱波的性质和机理。     

催化动力学极谱法测定痕量钯的研究

研究了催化动力学极谱法测定痕量钯的方法，在盐酸介质中，钯催化次磷酸钠与钼酸铵反应生成磷钼蓝，用氨－氯化铵缓冲液调节溶液ｐＨ值为９．２６可抑制催化反应条件，并在单扫描示波极谱仪上于－１．２４Ｖ（ｖｓ．ＳＣＥ）产生一灵敏极谱波，导数波高与钯０．０５～１．０ｎｇ．ｍｌ＾－１呈线性关系，检出限为０．０３ｎｇ．ｍｌ＾－１，研究了极谱波性质及机理，证明其为吸附波，方法用于合成样及电镀废液中的钯测定，结果满意。     

单扫描示波极谱法测定巯基乙酸的研究

在H2SO4－NH4OAc(pH3．5）溶液中，巯基乙酸有一灵敏的还原波。当使用单扫描极谱法时，其二阶导数峰电位位于－0．320V（vs.SCE)。用直流极谱法，单极描极谱法和循环伏安法研究了该体系的极谱行为和电极反应机理。结果表明，当使用单扫描极谱法时，该体系属于有吸附性的准可逆过程，测得电极反应电子转移数n=1,H^ ，反应数n′＝1。用单扫描极谱法可测定巯基乙酸，测定的线性范围为0.04-2.0mg.L^-1，该方法用于冷烫液中巯基乙酸的测定，结果满意。     

基于双波测量的催化动力学极谱法测定钒

在ｐＨ４．５ＨＡｃ－ＮａＡｃ缓冲溶液中，钍试剂分别于－０．３６Ｖ，－０．６０Ｖ产生两个灵敏的极谱波，基于钒对溴酸钾氧化钍试剂的催化作用，建立了双极谱波测量的催化动力学极谱法，钒浓度在０．７～１５μｇ／Ｌ与△Ｉ（△Ｉ１＋Ｉ２）呈线性关系，检测限为０．５μｇ／Ｌ。研究了极谱波性质及电极反应机理，本法简便，灵敏，准确，已用于直接测定水中痕量钒。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.