环氧溴丙烷或环氧氯丙烷／溴代萘／β—环糊精三元包接络合物的磷 …

在β－环糊精溶液中,环氧溴丙烷或环氧氯烷能够诱导α－溴代萘和β－溴代萘强的室温磷光。结果证明,ＥＢＨ比ＥＣＨ有更强的重原子 增强效应;α－ＢｒＮ／ＥＣＨ／β－ＣＤ三元包接合物的稳定性比β－ＢｒＮ／ＥＣＨ／β－ＣＤ稳定性更强。     

环糊精体系中4种多环芳烃敏化丁二酮室温燐光

对β－环糊精（β－ＣＤ）溶液中４种多环芳烃α－溴代萘（α－ＢｒＮ）、β－溴代萘（β－ＢｒＮ）、菲、敏化丁二酮（ＢＩＡＣ）的室温光（ＲＴＰ）进行了研究，β－ＣＤ能有效地增强敏化光强度，并从三重态能量、主客体分子几何尺寸大小等方面讨论了各种因素的影响。方法的线性动态范围上限受能量受体浓度的限制，其检出限达 １０－８ｍｏｌ／Ｌ。     

环糊精体系中4种多环芳烃敏化丁二酮室温磷光

对β－环糊精（β－ＣＤ）溶液中４种多环芳烃α－溴代萘（α－ＢｒＮ）、β－溴代萘（β－ＢｒＮ）、菲、Ｑｕ敏化丁二酮（ＢＩＡＣ）的室温磷光（ＲＴＰ）进行了研究，β－ＣＤ能有效地增强敏化磷光强度，并从三重态能量、主客体分子几何尺寸大小等方面讨论了各种因素的影响。方法的线性动态范围上限受能量受体浓度的限制，其检出限达１０＾－８ｍｏｌ／Ｌ。     

环氧溴丙烷作重原子微扰剂环糊精诱导室温燐光法测定7种痕量多环芳烃化合物

１引言环糊精诱导室温燐光法（ＣＤ－ＲＴＰ）测定痕量多环芳烃化合物的研究，我们曾做过大量的工作。在此基础上，本文研究ＴＮａ２ＳＯ３化学除氧技术用于环氧溴丙烷作重原子微扰剂β－ＣＤ－ＲＴＰ法测定痕量菲（Ｐｈｅｎ．），苊（Ａｃｅ．），芴（Ｆｌｕ．），７，８－苯并喹啉（７，８－ＢＱ），７－甲基喹啉（７－ＭｅＱ），α－４嗅代萘（α－ＢｒＮ），β－溴代茶（β－ＢｒＮ）中，均取得了成功。说明化学除氧技术在ＣＤ－ＲＴＰ法中具有普遍的意义。２实验部分２．１仪器和试剂ＬＳ－５０Ｂ型发光分析仪；菲、芴、苊（高效液相色…     

化学除氧技术在环糊精诱导室温磷光法中的应用(Ⅱ)2-溴乙醇作重原子微扰剂β-环糊精诱导室温磷光法测定四种痕量多环芳烃

以．２－溴乙醇作重原子微扰剂，用亚硫酸钠化学除氧技术，建立了β－环糊精诱导室温磷光法（β－ＣＤ－ＲＴＰ）测定痕量二氢苊、芴、菲、７，８－苯并喹啉的方法．该法除氧简便快速，体系澄清     

β—环糊精存在下直链脂肪醇诱导1—溴萘室温磷光光谱研究

研究了β－环糊精溶液中直链脂肪醇诱导１－溴萘的室温磷光光谱性质。结果表明，三元包络物中１－ＢｒＮ分子的磷光起初随醇中碳原子数的增加而增强，正戊醇对磷光呈现最大的敏化作用，随后从正己醇至正辛醇，磷光强度逐渐下降，测定了包络物组成和稳定常数，发现１－ＢｒＮ和Ａ：β－ＣＤ包络物的结合强度是三元包络物磷光强弱的决定性因素，并从三元包络物可能的结构解释了醇分子大小对室温磷光的影响。     

胺类对α—溴代萘／β—环糊精体系流体室温磷光的影响

首次研究了不同的胺对α－溴代萘（α－ＢｒＮｐ）／β－环糊精（β－ＣＤ）体系ＲＴＰ发射的影响,发现胺能显著增强α－ＢｒＮｐ／β－ＣＤ体系的ＲＴＰ发射,ＲＴＰ强度 随着胺的烷基链的增长和支锭的增加而增加,且当胺的用量是β－ＣＤ用量的一倍时,ＲＴＰ强度最大。由此认为,胺的影响主要应归因地胺分别从β－ＣＤ的二端接近,胺的－ＮＨ２基与β－ＣＤ的－ＯＨ基形成氢键,而其烷基从ＣＤ二端折向空腔,封住了ＣＤ的上、下     

一种新的重原子微扰剂氯代叔丁烷在亚硫酸钠化学除氧环糊精诱导 …

以氯代叔丁烷作重原子微扰剂采用亚硫酸钠化学除氧技术建立了菲、７,８－苯并喹啉、２－溴代萘在环糊精介质中的室温磷光分析法。通过对比平衡时间和第三组分的浓度对于β－环糊精／磷光体／氯代叔丁烷和β－环糊精／磷光体／叔丁醇两种体系中磷光的磷光强度、磷光寿命的不同影响,探讨了氯代叔丁烷和叔丁醇诱导产生室温磷光机理的差异。     

化学除氧技术在环糊精诱导室温磷光法中的应用：（Ⅱ）2—溴乙醇作？…

以２－溴乙醇作重原子微扰剂，用亚硫酸钠化学除氧技术，建立了β－环糊精诱导室温磷光法（β－ＣＤ－ＲＴＰ）测定痕量二氢苊，芴，菲，７，８－苯并喹啉的方法。该法除氧简便快速，体系澄清。     

RE（Ⅲ）与5—（2‘—羧基苯偶氮）绕丹宁及其衍生物的配合物稳定常数

采用ｐＨ－电位滴定法研究了乙醇溶液中ＲＥ（Ⅲ）与新型荧试剂Ｈ２Ｌ［５－（２＇－羧基苯偶氮）］绕丹宁（Ｂｒ－ＲＡＣＰ）、５－（４＇－氯代－２＇－羧基苯偶氮）绕丹宁（Ｃｌ－ＲＡＣＰ）、５－（４＇－溴代－２＇－羧基苯偶氮）绕丹宁定常数大小为ＲＡＣＰ＞Ｃｌ－ＲＡＣＰ＞Ｂｒ－ＲＡＣＰ。而与Ｎｄ（Ⅲ）的累积生成常数ｌｇβｍｌｈ随原子序数Ｚ增大时，研究了浓度对ｌｇβｍｌｈ的影响，测定了１５种稀土与ＲＡＣＰ的ｉｇ     

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%.     

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.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

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.