胍盐化合物[C(NH_2)_3]_(6.3)K[Nb_(1.3)W_(10.7)O_(40)H_2]·H_2O的合成及性质

通过粉状白钨酸和可溶性铌酸钾水溶液的反应,合成了十二聚系列的钨铌杂多阴离子胍盐化合物[C(NH_2)_3]_(6.3)K[Nb_(1.3)W_(10.7)O_(40)H_2]·H_2O,研究了其水溶液的酸碱稳定性。根据红外、拉曼和紫外光谱、化学性质,认为该化合物可能具有十二聚偏钨酸根阴离子的结构骨架。     

胍盐化合物[C(NH2)3]6.3K[Nb1.3W10.7O40H2]·H2O的合成及性质

通过粉状白钨酸和可溶性铌酸钾水溶液的反应,合成了十二聚系列的钨铌杂多阴离子胍盐化合物[C(NH₂)₃]_6.3K[Nb_1.3W_10.7O₄₀H₂]·H₂O,研究了其水溶液的酸碱稳定性。根据红外、拉曼和紫外光谱、化学性质,认为该化合物可能具有十二聚偏钨酸根阴离子的结构骨架。     

三缺位α-9钨镓杂多酸盐的合成与性质

本文报道了一种新的三缺位杂多阴离子α-[GaW_9O_(34)H_2]~(9-)的钠、钾、四甲基铵盐的合成方法,并通过元素分析、红外、紫外、极谱、热分析等方法对它进行了表征。α-[GaW_9-O_(34)H_2]~(9-)是一具有三个空位的杂多阴离子,它能与过渡金属离子反应生成具有Keggin结构的三取代钨镓杂多阴离子[GaW_9O_(37)M_3(H_2O)_3]~(R-)。     

11-钨钛合过渡金属杂多酸钾的合成与性质

11-系列不饱和杂多阴离子可作为配体与过渡金属或希土离子生成混合型杂多阴离子。由于这种无机高分子配合物对某些有机合成反应具有催化活性及抗病毒性能,新型化合物的合成仍吸引着人们的关注。11-钨钛杂多阴离子除与希土离子生成K_(13)[Ln(TiW_(11)O_(39))_2]·xH_2O型化合物外,也可与过渡金属离子生成混合型杂多阴离子。本文报道了K_n[TiW_(11)M(H_2O)O_(39)]·xH_2O(M=Mn~(2+)、Cu~(2+)、Zn~(2+)、Fe~(3+),Co~(3+)和Cr~(3+))型杂多酸盐的合成与性质。     

杂多配合物（X（NbO2）W11O39）^n—的合成与性质研究

钼钨的杂多配合物可作催化剂、电子显微镜的"着色剂"和分析试剂等[1]．近年来,含银的杂多配合物越来越引起人们重视[2]．Hill和Kim[3]报道了过氧化铌取代的杂多钨硅酸盐的合成及抗病毒性实验,指出含过氧化铌的杂多化合物对人体无害且对HIV－1病毒具有很高的活性．为了深人研究此类化合物,本文报道了具有Keggin结构的「X（NbO2）W1;O39]n-（X=Ga,Ge）杂多配合物的合成及性质,为抗病毒试验提供了4个新化合物．1实验部分1.1仪器与试剂BECKMAN－DU8B紫外分光光度计;ALPHACENTAURTFTIR红外分光光度计;384B型极谱分析仪…     

柱撑杂多阴离子粘土的合成及表征

采用水热合成及离子交换法将Keggin结构三铁九钨镓酸盐杂多阴离子GaW9Fe3（H2O）3嵌入Zn2Al型阴离子粘土层间，得到了新型层柱状微孔材料Zn2Al－GaW9Fe3．用元素分析、XRD、IR、XPS等手段对产物的组成和结构进行了表征．结果表明，杂多阴离子嵌入Zn2Al型阴离子粘土层间，使柱撑杂多阴离子粘土具有1．0nm的通道高度．     

负载型过氧磷钨杂多化合物上正己醇催化氧化成正己酸

由正己醇合成正己酸不仅可以提高附加值,还能生产己酸类香料以及多种医药产品．利用杂多过氧磷钨季铵盐催化剂,以对环境友好的H2O2 为氧化剂催化十八醇氧化成十八酸的研究已有报道［1,2],但合成负载型相转移催化剂并用于本课题的研究还未见报道．由于过氧磷钨十八烷基季铰盐催化剂（POWP）通常只有很小的比表面积,而SiO2不仅有大的比表面积,同时它所具有的表面羟基是杂多化合物的良好载体［2],POWP负载后的催化剂（POWPS）与未负载的POWP相比,将正己醇氧化为正已酸的收率提高了10多个百分点．     

十一钨钛杂多酸盐MnXW11TiO40(X=Si, B, Zn)的合成及其氧化还原性质

本文报道了十一钨钛杂多酸盐ＭｎＸＷ１１ＴｉＯ４０·ＸＨ２Ｏ（Ｘ＝Ｂ,Ｓｉ,Ｚｎ;Ｍ＝Ｋ,Ｈ）的合成方法及其氧化还原性质。三种杂多酸盐的１８３ＷＮＭＲ谱均是六线谱,表明其阴离子仍保持Ｋｅｇｇｉｎ结构。合成的化合物对烯烃环氧化反应具有催化作用。     

十一钨钛杂多酸盐MnXW11TiO40(X=Si, B, Zn)的合成及其氧化还原性质

本文报道了十一钨钛杂多酸盐M_nXW₁₁TiO₄₀·XH₂O(X=B, Si, Zn; M=K, H)的合成方法及其氧化还原性质。三种杂多酸盐的 ¹⁸³W NMR谱均是六线谱,表明其阴离子仍保持Keggin结构。合成的化合物对烯烃环氧化反应具有催化作用。     

α—和β—[SiW9Ti3O40]^1^0^—的合成及其钨—183核磁共振表征

本文报道了α－和β－［ＳｉＷ９Ｔｉ３Ｏ４０］＾１＾０＾－杂多阴离子的钾盐，四甲基铵盐的合成及其１８３ＷＮＭＲ表征，１８３ＷＮＭＲ谱中有两个峰，相对强度为２：１，表明其阴离子分别为Ａ型α－和β－Ｋｅｇｇｉｎ结构，即三个ＴｉＯ６八面体是角顶共用，合成化合物催化ＰｈＩＯ环氧化烯烃的性质。     

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.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.