二元羧酸二(二茂镱)的合成

本文报道了五个新的二元羧酸二(二茂镱)的合成:(COO)_2Yb_2(C_5H_5)_4(1),CH_2(COO)_2Yb_2(C_5H_5)_4(2),(CH_2COO)_2Yb_2(C_5H_5)_4(3),o-C_6H_4(COO)_2Yb_2(C_5H_5)_4(4),p-C_6H_4(COO)_2Yb_2(C_5H_5)_4(5),并考察了它们对空气的稳定性。     

多核钼、铁、铬醋酸盐的质谱研究

本文报道了络合物Mo_2(CH_3COO)_4、Cr_2(CH_3COO)_和(Fe_nCr_(3-n)O(CH_3COO)_6(H_2O)_3]NO_3·3H_2O(n=3,2,1,0)的质谱,并基于亚稳离子测量和同位素质量组合及丰度分布计算提出了它们的主要断裂过程。     

二茂镱羧酸衍生物的合成

本文报道了四种新的二茂镱羧酸衍生物的合成:Cp_2YbOCOC(CH_3)_3(1),Cp_2YbOCOCCl_3,(2),Cp_2YbOCOCH_2CH_3(3),Cp_2YbOCOCH_2Cl(4)。这些络合物都经元素分折、红外光谱及质谱鉴定。可能由于这些络合物具有桥式二聚体结构,因而增强了它们对空气的稳定性。     

某些含二茂铁基的酰氧基茂锆配合物的合成

本文由二氯二茂锆和二氯二(甲基环戊二烯基)锆与二茂铁羧酸钠盐反应合成了六种二茂铁酰氧基茂锆配合物,R_2ZrClY:R=C_5H_5,Y=FcCOO(1),FcCH_2COO(2),FcCOCH_2CH_2COO(3);R=CH_3C_5H_4,Y=FcCOO(4),FcCH_2C0O(5),FcCOCH_2CH_2COO(6)(Fc=二茂铁基)。     

含羧基的三核钼原子簇

本文总结了作者研究的一组合有羧基的三核钼原子簇的结果。这些簇合物分为两类。第一类有: (C_2H_5)_4N[Mo_3(μ_3-O)(μ-O_2CH)_3(μ-Cl)_3Cl_3] (Ⅰ) (CH_3)_4N[Mo_3(μ_3-O)(μ-O_2CH)_3(μ-Cl)_3Cl_3] (Ⅱ) (CH_3)_4N[Mo_3(μ_3-O)(μ-O_2CH)_3(μ-Br)_3Cl_3] (Ⅲ) (C_5H_7S_2)[Mo_3(μ_3-O)(μ-O_2CCH_3)_3(μ-Cl)_3Cl_3] (Ⅳ) (C_5H_7S_2)[Mo_3(μ_3-O)(μ-O_2CCH_3)_3(μ-Br)_3Cl_3] (Ⅴ) (C_2H_5)_4N[Mo_3(μ_3-O)(μ-O_3CCH_3)(μ-Cl)_3X_3] (Ⅵ) (X为Cl和Br统计分布的簇合物) (C_2H_5)_4N[Mo_3(μ_3-O)(μ-O_2CCH_2CH_3)_3(μ-Cl)_3Cl_3] (Ⅶ) (C_2H_5)_4N[Mo_3(μ-O)(μ-O_2CCH_2CH_2CH_3)_3(μ-Cl)_3Cl_3] (Ⅷ) (Ⅰ)-(Ⅷ)的簇阴离子具有下述通式: [Mo_3(μ_3-O)(μ-O_2CR)_3(μ-X)_3X_3~′]~-; R=H,CH_3,CH_3CH_3,CH_2CH_2CH_2:X和X′=Cl或Br。 属于第二类型的目前只有一个,即: [(C_2H_5)_4N]_2[Mo_3(μ_3-O)(μ-O_2CCH_3)_2(μ-Cl)_3Cl_5) (Ⅸ) 本文将扼要介绍这些簇合物的合成方法,晶体和分子结构的主要特征,并对成簇规律、结构变化规律以及μ_3-O的红外光谱的指认,给予简单的讨论。     

单体(η[5]-C5H5)2LuCl.OC4H8的生成和X-射线晶体结构

Dubeck等在1963年首先合成了二(环戊二烯基)氯化镥络合物,但晶体结构迄今未见报道。文献中仅有关于含氯桥的金属络合物二聚体,例如[(C_5H_5)_2Sc(μ-Cl)]_2,[(CH_3C_5H_4)_2Yb(μ-Cl)]_2,[Cp_2~LYb(μ-Cl)]_2和[Cp_2~LPr(μ-Cl)]_2C_P~L=1,3-[(CH_3)_3Si]_2C_5H_3)等晶体结构的研究。我们按文献方法制备了(η~5-C_5H_5)_2LuCl。测定了它的质谱及~1HNMR。再将经高真空升     

TiCl_4,MgCl_2和酯络合物的晶体结构和光谱性质——Ziegler-Natta高效聚丙烯催化剂结构研究之一

本文研究了直接有工业意义的TiCl_4、MgCl_2和酯络合物的晶体结构,并测定了粉末图,红外和紫外光谱。TiCl_4和PhCOOEt(L)生成(TiCl_4·L)_2和TiCl_4·2L两种络合物。MgCl_2与CH_3COOEt和H_3O形成MgCl_2·2CH_3COOEt·2H_2O络合物。这些分子间靠范德瓦力结合成晶体。相应的空间群分别为C_(2h)~5—P2_1/c,C_(2h)~5—P2_1/n和C_(2h)~5—C2/c。利用所得粉末图证实了研磨浸渍法制备催化剂过程中确有(TiCl_4·L)_2生成。对比高效催化剂和Mg络合物的红外光谱,表明催化剂表面络合物的配键与络合物相似。     

STUDY ON THE STRUCTURES OF COORDINATION COMPOUNDS OF N-(ortho-METHYL)-AND N-(ortho-METHOXY)-PHENYL IMINODIACETATO-Cu(Ⅱ)

The coordination compounds,{Cu[CH_3C_6H_4N(CH_2COO)_2]}.2H_2O and{Cu[CH_3OC_6H_4N(CH_2COO)_2]}.2H_2O,have been prepared and its crystal struc-tures determined.The final discrepancy factors are R=0.052,R_w=0.061 for(I)and R=0.052,R_w=0.039 for(Ⅱ).The geometry of the coordination poly-hedron with Cu(Ⅱ)is a distorted tetragonal pyramid for(Ⅰ)and an unsym-metrical and extended tetragonal bipyramid for(Ⅱ),respectively.The re-sults of EHMO calculations indicate that the ligand mainly provided thefield with very few of its electrons being coordinated to the central atom.     

[2,4—CH3）2C5H5]2TiCO的合成及结构

合成了开环夹心羰基化合物[2,4-(CH_3)_2C_5H_5]_2GCO,得到了该分子的单晶结构,[2,4-(CH_3)_2C_5H_5]_2TiCO晶体属于正交晶系,P2_12_12_1空间群,晶胞参数a=1.0078(5)nm,b=1.1909(8)nm,c=1.1946(5)nm,b=1.4337(13)nm~3,Z=4,R=0.054。单晶结构表明该分子为平行覆盖型开环夹心化合物,用EHMO方法计算了[2,4-(CH_3)_2C_5H_6]_2TICO的电子结构。     

有机钛化学 Ⅲ.1,5-环辛二烯的钛催化均相氢化

本文研究了一系列有机钛化合物(R-C_5H_4)_2TiCl_2(R=H,CH_3,C_2H_5,n-C_3H_7,CH_2-CHCH_2,CH_3CH-CHCH_2,CH_3OCH_2CH_2,C_2H_5OCH_2CH_2,cyclo-C_6H_(11)等)和还原剂((i-Bu)_3Al,LiAlH_4,i-C_3H_7MgBr)组成的低价钛催化体系对1,5-环辛二烯的均相催化氢化反应。结果表明,低价钛催化体系在温和条件下具有较好的催化活性,氢化时还同时发生异构化反应。并讨论茂环上取代基对反应的影响及催化机理。     

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.