钯（Ⅱ）－二溴羟基苯基荧光酮－溴化十六烷基三甲铵体系分光光度法的研究

在ｐＨ６．１～６．７的磷酸盐介质中，钯（Ⅱ）与二溴羟基苯基荧光酮－溴化十六烷基三甲铵于室温下反应，生成水溶性和稳定性皆佳的紫色三元配合物，最大吸收波长为６００ｎｍ，对比度为７０ｎｍ，表现摩尔吸光系数为９．４８×１０￣４Ｌ．ｍｏｌ￣（－１）’ｃｍ￣（－１），桑德尔灵敏度为１．１２×１０￣（－３）μｇ．ｃｍ￣（－２），钯含量在０～７．０μｇ／１０ｍＬ范围内服从比尔定律。据此提出了一个灵敏、简便分光光度法测定钯的新方法，用于合成试样和贵金属合金中微量钯的测定，结果满意。     

钯（Ⅱ）—二溴羟基苯基荧光酮—溴化十六烷基三甲铵体系分光光度法的…

在ＰＨ６．１－６．７的磷酸盐介质中，钯（Ⅱ）与二溴羟基苯荧光酮溴化十六烷基三甲铵于室温下反应，生成水溶性和稳定性皆佳的紫色三元配合物，最大吸收波长为６００ｎｍ，对比度为７０ｎｍ，表观摩尔吸光系数为９．４８ ×１０＾４Ｌ．ｍｏｌ＾－１ｃｍ＾－１，桑德尔灵敏度为１．１２×１０＾－３μｇ．ｃｍ＾－２，钯含量在０．７．０μｇ／１０ｍＬ范围内服从比尔定律。据此了一个灵敏、简便分光光度法测定钯的瓣方法，用于合     

新试剂3,5—二溴—4—偶氮8—羟基喹啉苯基荧光酮光度法测定微量铝

在溴化十六烷基三甲胺（ＣＴＭＡＢ）存在下，ＰＨ６，０的ＨＡｃ－ＮａＡｃ缓冲介质中，铝与新试剂３，５－二溴－４－偶氮８－羟基喹啉苯基荧光酮形成红色三元胶束配合物，最大吸收波长位于５６４ｎｍ，表观摩尔吸光系数ε为１．３５×１０＾５．ｍｏｌ＾－１．ｃｍ＾－１，铝浓度在０～５μｇ／２５ｍＬ范围内符合比耳定律，拟定的方法用于铝铁黄铜中微量铝的测定，结果满意。     

二溴羟基苯基光酮—溴化十六烷基三甲铵分光光度法测定微量铑

本提出了分光光度测定铑的新方法。在ｐＨ＝５．８～“．７的磷酸盐缓冲介质中，铑与二溴羟基苯基荧光酮－溴化十六烷基三甲争反应生成的配合物最大吸收峰位于６１０ｎｍ，对比度为８０ｎｍ，表观摩尔吸光系数为１．２９×１０＾５Ｌ·ｍｏｌ＾－１·ｃｍ＾－１。铑浓度在０～’．０μｇ／１０ｍＬ范围内符合比尔宣告。经离子交换分离消除贱金属等的干扰后，可用于二次合金中微量铑的测定，结果满意。     

二溴羟基苯基荧光酮－溴化十六烷基三甲铵分光光度法测定微量铑

本文提出了分光光度测定铑的新方法。在ｐＨ＝５．８～６．７的磷酸盐缓冲介质中，铑与二溴羟基苯基荧光酮－溴化十六烷基三甲铵反应生成的配合物最大吸收峰位于６１０ｎｍ，对比度为８０ｎｍ，表观摩尔吸光系数为１．２９×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）。铑浓度在０～５．０μｇ／１０ｍＬ范围内符合比尔定律。经离子交换分离消除贱金属等的干扰后，可用于二次合金中微量铑的测定，结果满意。     

5''''-硝基水杨基荧光酮荧光熄灭法测定微量钨

本文基于Ｗ（Ⅵ）－５′－硝基水杨基荧光酮（５′－Ｎ－ＳＡＦ）－Ｔｗｅｅｎ－８０体系的荧光熄灭效应，提出一种测定微量钨的新荧光方法。在０．２～１．０ｍｏｌ／Ｌ的硫酸介质中，在Ｔｗｅｅｎ－８０存在下，５′－Ｎ－ＳＡＦ存在两个激发峰，其激发波分别为λｅｘ１＝４７５ｎｍ，λｅｘ２＝５０５ｎｍ，发射波长为λｅｍ＝５２５ｎｍ。Ｗ（Ⅵ）与５′－Ｎ－ＳＡＦ形成１∶３的配合物。钨浓度在每２５ｍＬ０．２５～２．５μｇ范围内呈线性关系，检测限为每２５ｍＬ０．２５μｇ。本法灵敏度高，选择性好，不经分离可直接测定合金钢中的钨，结果满意。     

新试剂3,5—二溴—4—偶氮变色酸苯基荧光酮与锆（Ⅳ）显色反应的研究及应用

研究了在表面活性剂ＣＴＭＡＢ存在下，新试剂３，５－二溴－４－偶氮变色酸苯基荧光酮与锆（Ⅳ）显色反应条件和光度性质。在０．５ｍｏｌ／Ｌ盐酸介质中，形成红色胶束配合物，最大吸收波长为５３９ｎｍ，表观摩尔吸光系数为１．７４×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，锆含量在每２５ｍＬ０～１０μｇ范围内服从比尔定律。拟定方法用于直接测定铝合金中微量锆，结果满意。     

混合表面活性剂存在下二溴羟基苯基荧光酮光度法测定痕量铜

研究了在氯化十六烷基吡啶（ＣＰＣ）和吐温－４０存在下，铜与二溴羟基苯基荧光酮（ＤＢＨ－ＰＦ）显色反应，结果表明，在ｐＨ６．０－７．１的六次甲基四胺－盐酸缓冲溶液中，铜与ＤＢＨ－ＰＦ形成１：１配合物，其最大吸收峰全于５７０ｎｍ摩尔吸光系数１．２×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，铜含量在０～６μｇ／２５ｍＬ范围内符合比尔定律，方法用于测定环境水标样及牛肝粉标样中的痕量铜。     

二溴羟基苯基荧光酮荧光熄灭法测定微量钨

本文用荧光熄灭法研究了二溴羟基苯基荧光酮－溴化十六烷基三甲胺体系的显色反应和测定条件。在０．０２－０．１０ｍｏｌ／Ｌ硫酸介质中，钨与显色剂形成１：３的桔红色配合物，检出限为０．０８μｇ／２５ｍＬ范围内具人有线性关系。本法灵敏度高，选择性好，不经分离可直接测定合金钢中钨，结果满意。     

铝－5＇－硝基水杨基荧光酮－溴化十六烷基吡啶显色反应的研究及应用

本文研究了铝－５＇－硝基水杨基荧光酮（５＇－ＮＳＦ）－溴化十六烷基吡啶（ＣＰＢ）体系的显色条件。试验结果表明，在ｐＨ４．５～６．０范围内，铝与５＇－ＮＳＦ及ＣＰＢ形成紫红色的三元配合物，其最大吸收波长为５５８ｎｍ，摩尔吸光系数为１．３×１０￣５，配合物的组成为Ａｌ：５＇－ＮＳＦ：ＣＰＢ＝１：２：２。铝浓度在０～４μｇ／２５ｍＬ范围内符合比耳定律。方法用于石灰石、石英沙、石膏中铝的测定，结果令人满意。     

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.     

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.     

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.     

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.     

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.     

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.     

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%).     

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.