二茂铁基-1,1＇-二烷基二茂铁甲醇的合成与性质

10种二茂铁基－1,1'-二烷基二茂铁经LiAlH4还原得到10种相应的二茂铁基－1,1'-二烷基二茂铁甲醇。这类羟基化合物对酸的敏感性很高。由2种二茂铁基－1,1'-二乙基二茂铁甲醇与BF3在二氯甲烷中反应形成了稳定的二茂铁基－1,1'-二乙基二茂铁甲碳正离子。无需从反应混合中分离,该离子与乙胺作用得到了2种N－取代产物。由元素分析、红外光谱和核磁共振氢谱证实了化合物的结构。     

新型1,1′-二取代二茂铁双二氨基硫脲腙席夫碱化合物的合成及其对金属离子的电化学识别

以二茂铁双二氨基脲腙和取代醛为原料,经取代反应合成了7个新型的1,1′-二取代二茂铁双二氨基硫脲腙席夫碱化合物,其结构经UV,1HNMR,IR和元素分析表征。电化学研究表明,部分化合物对Ag+和Zn2+有较好的电化学识别能力。     

二茂铁基-1,1’-二烷基二茂铁甲醇的合成与性质

10种二茂铁甲酰基 -1 ,1 -二烷基二茂铁经 Li Al H4还原得到 1 0种相应的二茂铁基 -1 ,1 -二烷基二茂铁甲醇 .这类羟基化合物对酸的敏感性很高 .由 2种二茂铁基 -1 ,1 -二乙基二茂铁甲醇与 BF3在二氯甲烷中反应形成了稳定的二茂铁基 -1 ,1 -二乙基二茂铁甲基碳正离子 .无需从反应混合物中分离 ,该离子与乙胺作用得到了 2种 N-取代产物 .由元素分析、红外光谱和核磁共振氢谱证实了化合物的结构     

炔桥联不对称苯基取代双二茂铁衍生物的设计合成和电化学性质

以四苯基环戊二烯酮为起始原料,经过八步连续反应,成功地合成了3个炔桥联不对称五苯基取代双二茂铁衍生物Fc′-C≡C-Fc(1)、Fc′-C≡C-C≡C-Fc(2)和Fc′-C≡C-C≡C-Fc′(3)(Fc′=五苯基二茂铁基,Fc=二茂铁基)。在设计合成双二茂铁衍生物的过程中,首先经过4步反应,制备出已知化合物Fc′-H(4),再连续进行3步反应,分别得到3个中间化合物Fc′-COCH_3(5),Fc′-CCl=CHCHO(6)和Fc′-C≡CH(7),最后利用偶联反应,得到目标化合物1~3。利用X射线单晶衍射和循环伏安法,测定了化合物1、2和5、7的晶体结构,研究了化合物1~7的电化学性质。研究结果表明,分子的C-H…π键相互作用和空间位阻是导致化合物1和2分子中Fc′和Fc基空间排布取向不同的主要原因。当二茂铁的一个环戊二烯环上引入5个苯取代基时,铁中心的氧化还原电位将升高(E_p~a(Fc′-H)=0.658 V,E_p~a(Fc-H)=0.511 V)。与已知化合物Fc-C≡C-Fc(ΔE=0.215 V)和Fc-C≡C-C≡C-Fc(ΔE=0.134 V)相比,化合物1~3的氧化电位差值(ΔE)均有不同程度地提高(ΔE_1=0.236 V;ΔE_2=0.170 V;ΔE_3=0.146 V)。将1与Fc-C≡C-Fc,2与Fc-C≡C-C≡C-Fc和3进行比较发现,当炔桥两端连接不同的基团Fc′和Fc时,其氧化电位差值(ΔE)将明显提高。     

乙基二茂铁与乙酰丙酸甲酯的缩合反应

以多聚磷酸-浓硫酸-甲醇为催化剂和环已烷为溶剂,由乙基二茂铁与乙酰丙酸甲酯缩合合成4,4-双（乙基二茂铁基）成酸甲酯,转化率73%,产率84%。正交实验法获得的适宜反应条件：乙基二茂铁55mmol,乙酰丙酸甲酯75mmol,浓硫酸3.0mL,环已烷20mL,甲醇11mL。通过元素分析、IR、^1H NMR和^13C NMR确证了缩合产物的结构。     

聚乙二醇(PEG)桥连的新型双N-杂环卡宾-膦的合成及其在水相Suzuki反应中的应用

通过乙酸1-(2-二苯膦基二茂铁基)乙基酯与PEG-400衍生的双咪唑化合物反应,制得新型PEG桥连的双咪唑盐-膦配体,其结构经1HNMR,<31>PNMR和MS鉴定.初步催化研究表明,该PEG桥连的双咪唑盐一膦可作为支持配体在有机和水相中高产率地实现Pd催化的溴代芳烃和苯硼酸的Suzuki偶联反应.     

新型1,1′-双(4,5-二烷基)咪唑二茂铁的合成及其晶体结构

1,1′-二茂铁二甲醛与烷基二酮反应合成了3种新型的1,1′-双(4,5-二烷基咪唑)二茂铁,其结构经1HNMR,13C NMR,IR,ESI-MS及元素分析表征。1,1′-双(4,5-二苯基咪唑)二茂铁醋酸盐(1a′)的晶体结构经X-射线单晶衍射表征。1a′的晶体结构显示二茂铁的两个取代咪唑通过与醋酸的氢键作用形成顺式构型,探讨了顺式构型与反式构型的转化条件。1a′属单钭晶系,C2/c空间群,晶胞参数:a=15.832(4),b=19.255(4),c=14.781(4),β=121.837(3)°,V=3828.0(15)3,Z=4,F(000)=1 687,Dc=1.395 g.cm-3,Mr=804.07。     

新型1,1-双二茂铁基丁烷衍生物的合成

1,1-双二茂铁基丁烷和乙酸酐经Friedel-Crafts酰基化反应得6-乙酰基-1,1-双二茂铁基丁烷(2);2经LiAlH4还原得6-α-羟乙基-1,1-双二茂铁基丁烷(3);3经消除反应合成了6-乙烯基-1,1-双二茂铁基丁烷(4)。2~4为新化合物,其结构经1H NMR,IR,MS和元素分析表征。     

二茂铁甲酰基1,1'-二烷基二茂铁的合成与性质

在研制丁羟固体推进剂的高效不迁移燃速催化剂中 ,我们设计的目标物的结构为ＦｃＣＨ (ＯＨ)Ｆｃ′Ｒ2 (Ｆｃ =Ｃ5Ｈ5ＦｅＣ5Ｈ4 ,Ｆｃ′=Ｃ5Ｈ4 ＦｅＣ5Ｈ3,Ｒ为烷基 ) .该类化合物的特点是两个二茂铁核连在同一碳上 ,且含有羟基官能团 ,它们似应具有高效和不迁移的燃速催化性能[1].此类化合物的合成是由二茂铁甲酰基 1,1′ 二烷基二茂铁化合物的羰基还原为羟基实现的 .为此 ,我们较为详细地研究了 5种二烷基二茂铁在三氯化铝催化下的二茂铁甲酰化反应 .此项工作未见报道 .二烷基二茂铁的茂环有α(与烷基相邻 )和 β(与烷基相间 )两种Ｈ原…     

一个新颖的二茂铁羧酸混配合物的制备、晶体结构及电化学性质研究

本文以3-二茂铁羰基丙酸(L1)、1，1′-二茂铁二羰基-3，3′-双丙酸(L2)、2，2′-联吡啶胺(dpa)以及Zn(Ac)₂·2H₂O为原料合成了一个结构新颖的混配合物[Zn₂(L1)₂(L2)(dpa)]。X-射线单晶衍射分析表明，该配合物是一个中心对称的双核配合物，并在N-H…O氢键和C-H…O氢键的作用下形成了二维的超分子化合物。采用差示脉冲对该配合物的电化学性质进行了初步的研究。     

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.     

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.