一种新型的吡唑衍生物的合成

近年来,多齿含氮的配体在有机配合物的合成和研究中日益受到重视,不仅用在高氧化态、缺电子中心的高价过渡金属有机配合物上,而且已开始在低氧化态、富电子中心的低价过渡金属有机配合物上应用,其中一个重要原因是自然界中许多金属酶普遍含有以氮为配位原子的配体.我们合成了N,N'-二(3,5-二甲基吡唑)烷的衍生物1,同时分离得到了一种新型的环状化合物2.     

非对称结构的Salen型镍、铜、锰配合物的合成及性质

本文设计合成了两种新型Salen配体H2L1(N-苯基-N-(2-羟基-5-甲基苯基)-N′-(2,5-二羟基苯基)-4,5-二甲氧基邻苯二胺)和H2L2(N-苯基-N-(2-羟基-5-甲基苯基)-N′-(2-羟基-3,5二叔丁基苯基)-4,5-二甲氧基邻苯二胺)及相应的过渡金属配合物MLn(M=Ni、Cu、Mn;n=1、2)。分别采用核磁、质谱、元素分析、红外光谱和紫外-可见光谱对目标化合物进行了表征。研究了两种配体及其金属配合物的荧光性质,探讨了配体结构及中心金属离子对其荧光性质的影响。研究发现,由于氢键的作用使得配体H2L1的荧光强度远低于H2L2;中心金属离子的嵌入对H2L2的荧光强度有明显的猝灭作用。用循环伏安法研究了配体及其金属配合物的电化学氧化还原性质,并测定了配体及其金属配合物溶液的电导率、摩尔电导率。结果表明,镍、铜、锰配合物的氧化还原过程均为准可逆的单电子过程;且在所研究的配体和配合物中,金属锰配合物溶液的导电能力较强。     

双[N,N'-亚烃基-2,2'-(芳亚甲基)二(3,4-二甲基吡咯-5-醛缩亚胺)]合双锰(Ⅱ)的合成、光谱特征及拟酶催化性能研究

首次报道了新型Schif碱类配体双[N,N-亚烃基-2,2-(苯亚甲基)二(3,4-二甲基吡咯-5-醛缩亚胺)]和双[N,N-(1,2-亚乙基)-2,2-(4-甲氧基苯亚甲基)二(3,4-二甲基吡咯-5-醛缩亚胺)]及其双锰配合物的合成方法、光谱特征及用配合物催化PhIO单加氧化环己烷反应的研究。     

金属有机配合物的非线性光学特性

从过渡金属有机配合物的中心金属、配体和几何结构的多样性、多变的金属氧化态和金属与配体的电子供－受作用评述了金属有机配合物的二阶、三阶非线性光学效应的分子结构特征和最新进展。参考文献２６篇。     

1,4,8,12-四甲基-1,4,8,12-四氮(杂)十五环烷合铜(Ⅱ)的合成

近二、三十年来,四氮(杂)大环配体配合物(A)一直是很活跃的研究领域。为了研究配体对过渡金属离子的环效应和过渡金属离子的氧化-还原特性,N原子的甲基取代物中12、14员环配体的合成已有报导。     

相转移催化合成N,N''-二(3,5-二甲基吡唑)烷

本文用相转移催化方法, 在C6H6/H20两相里, 3,5-二甲基吡唑与α,ω-二溴代烷反应合成了一系列N,N'-二(3,5-二甲基吡唑)烷配体。     

Salen型铜(Ⅱ)和镍(Ⅱ)配合物的合成与电化学性质

合成了2种salen型配体及其具有N2O2配位模式的salen型铜、镍金属配合物ML1和ML2[M=Cu,Ni;salen型配体L1=N,N'-双(4-羟基-邻羟苯亚甲基)-2,2'-联苯二胺;L2=N,N'-双(3,5-二叔丁基-邻羟苯亚甲基)-2,2'-联苯二胺];并通过核磁共振波谱(1H NMR)、电喷雾质谱(ESI-MS)、红外光谱(FT-IR)、紫外-可见光谱(UV-Vis)和元素分析等对配体及目标金属配合物进行了表征。循环伏安法电化学研究发现,在-1.5~+1.5 V电势扫描中,CuL2和NiL1只有一组单电子准可逆氧化还原过程,而NiL2发生了两次氧化还原反应。     

二氰基二硫纶和邻菲咯啉二酮镍（Ⅱ）,铜（Ⅱ）,锌（Ⅱ）配合物的电子光谱及分子内

各种均一配体的金属二硫纶[1～4]、金属二亚胺[5,6]以及二硫纶和二亚胺混合配体的金属配合物[7,8],因其具有特殊的氧化还原性和光、电、磁功能,近10多年来一直受到科学家们的高度重视.笔者的兴趣在于二氰基二硫纶(mnt2-)的过渡金属配合物,以及二氰基二硫纶和α,α′-二亚胺混合配体过渡金属配合物的合成、性质、结构和电子功能研究[9～12].这些配合物不仅本身具有优异的气敏、光敏、催化等功能性,而且也是合成金属四氮杂卟啉的前驱物[13～14]和自组装有序分子聚集体的功能元件之一[15].……     

二氰基二硫纶和邻菲咯啉二酮镍(Ⅱ)、铜(Ⅱ)、锌(Ⅱ)配合物的电子光谱及分子内荷移跃迁

各种均一配体的金属二硫纶[1～4]、金属二亚胺[5,6]以及二硫纶和二亚胺混合配体的金属配合物[7,8],因其具有特殊的氧化还原性和光、电、磁功能,近10多年来一直受到科学家们的高度重视.笔者的兴趣在于二氰基二硫纶(mnt2-)的过渡金属配合物,以及二氰基二硫纶和α,α′-二亚胺混合配体过渡金属配合物的合成、性质、结构和电子功能研究[9～12].这些配合物不仅本身具有优异的气敏、光敏、催化等功能性,而且也是合成金属四氮杂卟啉的前驱物[13～14]和自组装有序分子聚集体的功能元件之一[15].……     

二氰基二硫纶和邻菲咯啉二酮镍(II)、铜(II)、锌(II)配合物的电子光谱及分子内荷移跃迁

各种均一配体的金属二硫纶 [1～ 4 ]、金属二亚胺 [5,6]以及二硫纶和二亚胺混合配体的金属配合物 [7,8] ,因其具有特殊的氧化还原性和光、电、磁功能 ,近 1 0多年来一直受到科学家们的高度重视。笔者的兴趣在于二氰基二硫纶 (mnt2 - )的过渡金属配合物 ,以及二氰基二硫纶和α,α′-二亚胺混合配体过渡金属配合物的合成、性质、结构和电子功能研究 [9～ 12 ] 。这些配合物不仅本身具有优异的气敏、光敏、催化等功能性 ,而且也是合成金属四氮杂卟啉的前驱物 [13～ 14 ]和自组装有序分子聚集体的功能元件之一[15] 。　　最近 ,笔者合成和表征了…     

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.