锆氢化反应研究 VI:环氧化合物的选择还原

环氧化合物还原成醇,是较为常见的反应。其区域选择性取决于所使用的还原剂。一般规律是:LiAlH_4类型的亲核性复合金属氢化物从空间障碍较小的部位接近氧,从而获得取代基较多的醇;而硼烷(尤其在BF_3存在之下)或铝烷类型的亲电性金属氢化物则使环氧化合物从相反方向开环并主要获得取代基较小的醇。锆氢试剂(Cp_2ZrHCl)对羰基化合物的还原已经详细研究,本文将研究环氧化合物的还原及其区域选择性,并进一步认识锆氢试剂在反应中的作用及其本质。     

由(E)-β-碘代烯基砜和末端炔合成多取代的1,3-烯炔

通过(E)-b-碘代烯基砜与末端炔的Sonogashira偶联反应,以中等到良好的产率合成了磺酰基取代的1,3-烯炔。在NiCl2(PPh3)2催化下,产物与格氏试剂发生脱磺酰基偶联反应,磺酰基被进一步转化为不同的取代基。     

锆氢化反应研究（Ⅳ）：—芳腈的锆氢化反应及其在合成中的应用

芳腈在温和条件下进行锆氢化反应,所得产物经水解得到芳醛;若经酰基化则得到N-酰基不饱和胺。后者不稳定,在室温下与甲醇发生加成反应得N-(α-甲氧基苄基)苯甲酰胺。过量的锆氢化试剂与芳腈反应,继之进行酰基化,得到二元酰基化产物,两个酰基分别加到腈基的碳与氮原子上。     

区域选择性合成2-取代磺酰基亚肼基-3-全乙酰糖基-2,3-二氢噻唑及其表征、生物活性研究

以取代磺酰肼和糖基异硫氰酸酯反应,生成8种1-取代磺酰基-4-全乙酰糖基氨基硫脲,然后在ClCH2CHO/CH3COONa/DMF条件下关环,区域选择性地合成了一系列新型2-取代磺酰基亚肼基-3-全乙酰糖基-2,3-二氢噻唑.化合物3e的1H-13CHMBC谱图表明1-取代磺酰基-4-全乙酰糖基氨基硫脲与氯乙醛的缩合反应关环位置为氨基硫脲的N-4,而非N-2.所有新化合物的结构均经过1HNMR,13CNMR和元素分析确证,生物活性初步测定结果表明该类二氢噻唑化合物具有一定的除草活性.     

聚苯乙烯基N-甲基-N-酰基磺酰胺树脂的制备及其作为酰基转移试剂在酰胺合成中的应用

聚苯乙烯基磺酰氯树脂(树脂1)与甲胺水溶液在吡啶的催化作用下反应，制备了N—甲基磺酰胺树脂(树脂2)．用酰氯在吡啶中与树脂2反应，得到N—酰基—N—甲基磺酰胺树脂(树脂3)．树脂3作为胺底物的酰基转移试剂，用来制备N—取代的酰胺，收率14～81％．树脂3可以有选择性地酰化乙醇胺中的氨基而不会使羟基酰化。     

N'-取代苯磺酰基N-(4,6-二取代均-三氮苯-2-基)乙二胺的合成

N-芳基磺酰乙二胺与三聚氰氯反应获得三个新缩合产物, 缩合产物再与醇钠反应得到六个N-取代苯磺酰基-N'-取代均三嗪基乙二胺衍生物, 所有化合物都表现出对植物生长的抑制作用, 可用于筛选除草剂.     

4,5-二苯基-2-取代基-1-磺酰基咪唑的合成

用多种磺酰氯或磺酸酐与4,5-二苯基-2-取代-1-磺酰基咪唑负离子反应, 合成了10个未见文献报道的1-磺酰基咪唑类化合物. 所有化合物均经1H NMR和13C NMR确证.     

银催化9-联烯嘌呤与氟代双(苯磺酰基)甲烷的单氟甲基化反应（英文）

以氟代双(苯磺酰基)甲烷为氟化试剂,AgF(3 mol%)为催化剂,实现了9-联烯嘌呤的单氟甲基化反应,并在不同取代基的9-联烯嘌呤底物中均表现出了较好的收率.单氟甲基化反应具有较高的化学选择性和E-选择性.同时,这种方法为合成含氟嘌呤化合物提供了一种有效的途径.     

α,α'-双亚甲基锆杂环戊烷的构建及其在1,5-己二烯合成中的应用

锆杂环化合物因其多种反应活性而备受关注.2分子1,1-二取代联烯在低价锆物种"Cp2Zr(II)"作用下可发生分子间还原偶联形成α,α'-双亚甲基锆杂环戊烷,反应的区域及立体化学受到取代基空间效应影响显著.α,α'-双亚甲基锆杂环戊烷中含有两个sp2碳-金属键,与多种亲电试剂体系反应分别生成多种类型有机分子,可为2,5-二卤代-1,5-己二烯、具有1,5-二烯骨架的1,6-二羰基化合物等多功能有机分子提供新合成方法学.     

双(1,2-二苯基环戊二烯基)二氯化锆化合物发光光谱行为及取代基效应

以干燥的正己烷为溶剂, 在N2气保护下, 研究了金属有机化合物双(1,2-二苯基环戊二烯基)二氯化锆(2)、 双(4-甲基-1,2-二苯基环戊二烯基)二氯化锆(3)和双(1,2,4\|三苯基环戊二烯基)二氯化锆(4)的发光光谱行为. 研究结果表明, 该系列化合物具有良好的发光性能, 且荧光光谱的发射波长可通过改变环戊二烯基4位上的取代基R进行调节. 发射光波长大小顺序为Ph>CH3>H.     

Alkyl-, Aryl-, Vinyl-, and Heterosubstituted Organozirconium Compounds. -Selective nucleophiles of low basicity. Preliminary communication

Solutions of the title compounds are accessible from organolithium reagents and trialkoxyzirconium chloride (equation 2). In contrast to their titanium analogues, vinylzirconium reagents are stable enough to be employed. Generally, organozirconium reagents are highly selective aldehyde and ketone carbonylophiles of exceedingly low basicity (Tables 1, 2, 3 and typical procedure).     

Stereoselective Synthesis of E-Vinyltellurides by the Reaction of Vinylic Zirconium with ArTeTeAr

1-Alkynes react with Cp₂Zr(H)Cl (Cp= η-C₅H₅) giving vinylzirconium complexes, which are trapped with diarylditellurides to afford (E)-vinylic tellurides.     

Nickel-catalyzed cyclizations and couplings with vinylzirconium reagents

[reaction: see text] 1,3-Dienes were prepared by a variety of nickel-catalyzed couplings and cyclization processes. Intermolecular or partially intramolecular couplings of alkynes, vinylzirconium reagents, and either aldehydes or enones efficiently proceeded to generate a broad range of functionalized dienes.     

Synthesis and properties of tetrazole-containing oligomers

Linear, star-shaped, and hyperbranched oligomeric compounds containing tetrazole cycles in the main chains are synthesized via the polycondensation (polyalkylation) of N-H unsubstituted bis(tetrazoles), tris(tetrazoles), and tetrakis(tetrazoles) with compounds containing mobile halogen atoms. Some properties of the oligomers are studied. Some of the oligomers are characterized by high density and a large content of nitrogen.     

含取代苯甲酰基硫脲的核苷类化合物的合成及杀菌活性研究

为了发现具有杀菌活性的新型先导化合物,基于几丁质合成酶催化作用机制,通过活性亚结构拼接方法,保留多氧霉素和尼克霉素中的活性尿苷部分,将具有良好杀菌活性的硫脲基团引入,设计合成了一系列含硫脲结构的核苷类化合物.以尿苷为原料,经5步反应制得目标物,其结构经IR,1H NMR及元素分析确证.初步生测结果表明,部分化合物对芦笋茎枯病(Phomopsisasparagi bubak)表现出明显的抑制活性,其中6m的抑制率在50μg/mL浓度下为97.2%,与相同浓度的多氧霉素B活性(100%)接近.     

Synthesis and Antimicrobial Evaluation of Calycanthaceous Alkaloid Derivatives

Chemistry of Natural Compounds - To find pesticidal lead compounds with high activity, a series of new chimonanthine derivatives was synthesized via the introduction of the functional group at the...     

Synthesis and properties of novel hole-transporting materials with triphenylamine units

Two novel organic hole-transporting materials have been synthesized by combination of triphenylamines(TPA) viaπ-conjugated bonds using Wittig reaction.The structures were characterized by NMR,FT-IR and HRMS.The optical,electrochemical and thermal properties of the materials were studied in detail.The results show that these two compounds have blue emission,proper HOMO levels and high thermal stability.Furthermore,a quantum chemical calculation on electron distribution of the two compounds was performed, which suggests the current synthesized materials would be promising candidates for hole-transporting materials.     

Synthesis and application of moisture-stable methallylsilanated phosphorylcholine as a surface modifier

New methallylsilanated phosphorylcholine (MASPCs) were synthesized via a copper-catalyzed ‘click’ reaction and demonstrated excellent moisture stability. Hydroxylated silicon compounds, silanol, and silica were grafted or modified by MASPCs in the presence of triflic acid (TfOH) and they possessed a good grafting efficiency and high loading rate.     

Synthesis and properties of trigeminal tricationic ionic liquids

Novel trigeminal tricationic ionic liquids (TTILs) have been successfully synthesized in high yields by means of Menschutkin quaternization via an S(N)1 mechanism. This reaction presents a new convenient method for transforming glycerol into multifunctional compounds. The physical properties of a series of TTILs were characterized by using a variety of techniques. The prepared salts were tested for antimicrobial activity. Electrochemical characterization of TTILs was also performed, which allowed the estimation of the conductivity of these new compounds, to establish their electrochemical stability window and capacitance properties over a wide range of temperatures. A good correlation of the physical properties of TTILs with capacitance values was observed.     

Synthesis of new acetal aza-cage compounds via ozonolysis of bis-endo-diol- and diacylnorbornene derivatives

We synthesized acetal aza-cage compounds directly via ozonolysis of 2,3-bis-endo-diol- and diacylnorbornenes in dichloromethane at ?78 °C. Ozonolysis of the diols followed by addition of amines gave the aza-cage compounds in high yields. The reaction mechanism for the formation of this type of aza-cage compounds is proposed to proceed via the hydroperoxide intermediate. Ozonolysis of the diacetyl norbornene followed by addition of (1) primary amines gave monoaza-cages and diaza-cage, (2) tert-butylamine gave hydroxyl lactone and diaza-cages, and (3) amino acid ester gave optically active aza-cages, in which one compound was converted into chiral aminoalcohol and structure of another was proven by X-ray analysis. A mechanism via the final ozonide and the imine intermediates is proposed for the formation of this type of aza-cages.