茂钛配合物—纳米氢化钠双组分高活性加氢催化剂的研究

提出了带有不同取代基的茂钛配合物与纳米氢化钠（ＮａＨ）组成的高活性加氢催化剂，在常温常压下，取代茂钛配合物ＴｉＣｌ２／ＮａＨ对１－己烯的加氢反应有极高的初始活性，ＴＯＦｍａｘ达到１１０ｍｏｌＨ２／（ｍｏｌＴｉ．ｓ），催化转换数达到２２２００ｍｏｌＨ２／（ｍｏｌＴｉ）。该催化体系对底物有明显的专一选择性，只有端烃才能发生加氢反应，且无民构化副反应发生，纳米氢化钠的助剂作用是该催化体系高活性关键因素。     

亚胺膦钌配合物RuCl2P2N2的合成和催化性能

ＲｕＣｌ２（Ｐｈ３Ｐ）４或ＲｕＣｌ２（ＤＭＳＯ）４在甲苯中直接与等摩尔的亚胺膦配体Ｎ，Ｎ－双－［邻－（二苯基膦苯亚甲基）］乙二胺（Ｐ２Ｎ２）在甲苯中回流反应，高产率地合成了反式配位的双亚胺双膦钌配合物ｔｒａｎｓ－ＲｕＣｌ２Ｐ２Ｎ２．在温和条件下，该配合物作为新型催化剂有效地催化α，β－不饱和酸和几种功能团烯烃的选择加氢反应．讨论了可能的催化活性物种．     

锰配合物催化加氢反应的研究进展

过渡金属催化不饱和有机化合物的加氢反应具有原子经济性高、绿色环保等优点,一直是有机化学研究的重点和难点.当前加氢反应中最常用的催化剂主要是铑、钌、铱、钯等贵金属,以储量丰富的金属锰作为催化剂更符合可持续发展的要求,在过去的几年中,锰催化的醛、酮、酯、腈、酰胺等不饱和化合物的氢化反应得以实现.我们系统地总结了锰配合物在加...     

两相催化体系中α，β－不饱和醛的选择加氢反应研究Ⅱ．RuCl_3和TPPTS形成催化活性物种过程中的~（31）PNMR研究

两相催化体系中α，β－不饱和醛的选择加氢反应研究Ⅱ．ＲｕＣｌ_３和ＴＰＰＴＳ形成催化活性物种过程中的~（３１）ＰＮＭＲ研究王祥智，陈华，黎耀忠，李贤均（四川大学化学系，成都６１００６４）刘华骥（四川大学分析测试中心）关键词钌－膦配合物，选择加氢，（３１...     

水溶性钯配合物催化柠檬醛的选择加氢反应研究 Ⅰ.反应条件的影响

研究了在水／有机物两相体系中水溶性钯－膦配合物催化柠檬醛的加氢反应．考察了反应温度、氢气压力、底物和催化剂浓度、反应时间、水相ｐＨ值等对该反应的影响，并与几种柠檬醛衍生物的加氢结果进行了比较．发现仅用蒸馏水作水相，则主要产物是二氢香茅醛（＞９３％）；而水相中加入Ｎａ２ＣＯ３后，则主要产物为香茅醛（９７％），且加氢速度比同样条件下使用Ｐｄ／Ｃ催化剂快得多．     

均相苯乙酮加氢反应研究

合成了一种新的钌膦配合物[RuCl2(Dmpp)2en](Dmpp=4-(2，6-二甲氧吡啶基)二苯基膦，en=乙二胺)，对其结构进行了表征．系统研究了反应温度，氢气压力，底物和催化剂的比例，碱和催化剂的比例等反应条件对[RuCl2(Dmpp)2en]催化的芳香酮加氢反应活性的影响，证明其在苯乙酮加氢反应中具有很好的催化活性．     

两相催化体系中α，β－不饱和醛的选择性加氢反应研究Ⅰ．水溶性钌－膦配合物催化肉桂醛的加氢性能

本文研究了两种水溶性钌－膦配合物ＲｕＣｌ_２（ＴＰＰＴＳ）_３和Ｒｕｃｌ_２（ＣＯ）_２（ＴＰＰＴＳ）_２［ＴＰＰＴＳ为：Ｐ（ｍ－Ｃ_６Ｈ_４ＳＯ_３Ｎａ）_３］的合成，在水相和有机相组成的两相催化体系中，考察了它们衍生出的活性物种和以ＲｕＣｌ３－ＴＰＰＴＳ原位合成的活性物种对肉桂醛的选择加氢性能，并对反应温度（２０—８０℃），氢压（２—６ＭＰａ），催化剂浓度（１．１２×１０~（－３）～４．５０×１０~（－３）ｍｏｌ／Ｌ），配体ＴＰＰＴＳ浓度（９．０×１０~（－３）～５．４×１０~（－２）ｍｏｌ／Ｌ），表面活性剂浓度和反应时间的变化对选择加氢反应的影响进行了详细研究。实验结果表明，ＲｕＣｌ_３－ＴＰＰＴＳ原位合成配合物的催化加氢活性最高，而在金属Ｒｕ上羰基的配位将使加氢活性降低，表面活性剂ＣＴＡＢ是有效的促进剂，它的加入可大大提高加氢活性，选择适当的ＣＴＡＢ浓度，在反应结束后水相与有机相分层迅速，有利于Ｒｕ催化剂的分离，在所考察的反应条件下，肉桂醛选择加氢生成肉桂醇的转化率大于８０％，选择性达９６％以上。     

钛配合物烯烃聚合催化剂研究的新进展

线性低密度聚乙烯是聚烯烃材料中亟待发展的高附加值树脂，近年来获得了快速发展和产业化应用，其关键推动力在于钛配合物催化剂的研究发展。本文综述了近几年钛配合物催化剂研究的新进展，探讨了配合物结构变化对催化剂活性和共聚性能的影响规律。     

负载型Sn2(OMe)4/SiO2催化剂的制备及其催化CO2和CH3OH直接合成碳酸二甲酯的性能

 采用表面改性法制备了负载型Sn2（OMe）4／SiO2双核桥联配合物催化剂，用IR，TPD和微反技术对催化剂的表面结构、化学吸附性质和催化活性进行了研究．结果表明，双核桥联Sn2（OMe）4／SiO2配合物中存在Sn－O－Si双齿配位形式，甲氧基以桥基形式联结两个Sn4＋离子；CO2在催化剂表面以桥式吸附态和甲氧碳酸酯基吸附态存在，而CH3OH只以分子吸附态存在．在反应温度413K，压力0．5MPa，反应空速1500h－1以及CH3OH与CO2的摩尔比为2～2．5的反应条件下，CO2和CH3OH在Sn2（OMe）4／SiO2催化剂上生成碳酸二甲酯的选择性达到近100％．根据实验结果，提出了CO2与CH3OH在Sn2（OMe）4／SiO2催化剂表面上的反应机理，反应物分子共吸附于催化剂表面同一活性位上及CO2的甲氧碳酸酯基吸附态的形成是反应顺利进行的关键因素．     

聚γ—（β—氰乙硫基）丙基硅氧烷铂配合物的合成与催化性能

γ－巯丙基三乙氧基硅烷与丙烯腈反应，得到γ－（β－氰乙硫基）丙基三乙氧基硅烷．后者经气相法二氧化硅固载，再与氯亚铂酸钾反应，合成了聚γ－（β－氰乙硫基）丙基硅氧烷铂配合物．研究了该铂配合物对不饱和烃与三乙氧基硅烷的硅氢加成反应的催化特性．     

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.     

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.     

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.     

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.