1,2,5-噻二唑衍生物电子结构的紫外光电子能谱研究

首次报导了１,２,５－噻二唑衍生物３－氯－１,２,５－噻二唑（Ａ）和３,４＝二氯－１,２,５－噻二唑（Ｂ）化合物的紫外光电子能谱（ＵＰＳ）,谱带的指认建筑在对谱带形状、相对强度、实验电离能（ＩＰＳ）的分析以对研究分子Ｇａｕｓｓｉａｎ ９４ＳＴ０－６Ｇ从头计算电离能（－ε１）。化合物Ｂ ＵＰＳ谱带的ＩＰＳ比相应的化合物Ａ的ＩＰＳ均你芝归结为Ｂ分子中两个取代Ｃ１原子上电子的拥挤效应。计算的Ｂ的 有量（     

A convenient synthesis of 1,3,4-thiadiazole and 1,3,4-oxadiazole based peptidomimetics employing diacylhydrazines derived from amino acids

Synthesis of novel orthogonally protected 1,3,4-thiadiazole and 1,3,4-oxadiazole tethered dipeptide mimetics is described. Both the heterocycles are prepared via a set of diacylhydrazines derived from amino acids. 1,3,4-Thiadiazoles are synthesized by dehydrosulfurization using Lawesson’s reagent while 1,3,4-oxadiazoles are obtained by EDC mediated cyclodehydration.     

The ring opening of 3,4-dichloro-1,2,5-thiadiazole with metal amides. A new synthesis of 3,4-disubstituted-1,2,5-thiadiazoles

We have developed a new synthesis of 3,4-disubstituted-1,2,5-thiadiazoles. The methodology is based on the ring opening of readily available 3,4-dichloro-1,2,5-thiadiazole with metal amides to afford a stable synthon, which is then transformed into the 3,4-disubstituted-1,2,5-thiadiazole derivatives via two consecutive reactions with O-, S-, N- or C-nucleophiles.     

MCM-41分子筛负载氯化铝催化丙烯酸甲酯与1-辛烯共聚

以MCM-41分子筛负载氯化铝为催化剂, 催化丙烯酸甲酯与1-辛烯共聚合反应, 利用称重法测定聚合物产率, 利用核磁共振氢谱分析共聚物组成, 利用凝胶渗透色谱分析共聚物相对数均分子质量, 研究了聚合物产率和共聚物组成随聚合反应时间的变化规律, 考察了溶剂、 催化剂组成和催化剂用量对共聚合结果的影响及催化剂的循环使用性能. 结果表明, 聚合物产率随时间呈S形增长, 而共聚物组成随时间保持恒定, 与氯化铝催化体系规律一致; 溶剂由二氯甲烷改变为乙醇或二甲苯主要影响聚合物组成, 对聚合物相对数均分子质量及其分布影响不大; 催化剂中活性组分的增加有利于增加共聚物中1-辛烯单元的含量, 但对聚合物分子量及分子量分布影响不大; 催化剂中活性组分含量一定时, 随催化剂与单体摩尔比从0.125增加到0.5, 共聚物中1-辛烯单元含量增加, 继续增大催化剂用量不利于提高共聚物中1-辛烯单元含量. 催化剂重复使用3次后仍具有良好的催化活性, 将烯烃单元引入共聚物中, 获得1-辛烯单元摩尔分数达30.1%的聚(丙烯酸甲酯-co-1-辛烯)共聚物.     

金催化制备氯乙烯单体进展

本文综述了Au用于乙炔氢氯化反应的研究历史、最新研究进展及商业化进程。讨论了使用不同前驱体和添加第二金属助剂等方法对催化剂性能的改进,探讨了活性金物种的性质。尽管HgCl2会导致环境污染等问题,但全球大量聚氯乙烯(PVC)的生产仍采用HgCl2作为催化剂。由于中国计划未来几年内将不再使用Hg生产PVC,因此急需探索替代催化剂。数十年来人们普遍认为Au是该过程的最佳替代催化剂,这主要是因为与其他金属相比,金催化剂的选择性更高。     

Synthesis of some substituted 1,2,4-triazole and 1,3,4-thiadiazole derivatives

New S-substituted 1,2,4-triazole and 1,3,4-thiadiazole derivatives have been prepared. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1712–1715, November, 2008.     

The chemistry of 1,2,5-thiadiazoles V. Synthesis of 3,4-diamino-1,2,5-thiadiazole and [1,2,5] thiadiazolo[3,4-b]pyrazines

The o-diamine, 3,4-diamino-1,2,5-thiadiazole ( 2 ), was synthesized from 3,4-dichloro-1,2,5-thiadiazole ( 3 ) hy three methods. Aqueous glyoxal cyclized 2 into [1,2,5]thiadiazolo[3,4–6]-pyrazine ( 14 ). 3,4-Dichloro-1,2,5-thiadiazole 1,1-dioxide ( 18 ) reaeted with 2 to give 1,3-dihydro-bis[1,2,5]thiadiazolo[3,4-b:3′,4′-e]pyrazine 2,2-dioxide ( 19 ). The reaction of 2 with selenium oxyehloride led to [1,2,5]selenadiazolo[3,4-c] [1,2,5]thiadiazole ( 12 ). Ring closure of 2,3-diaminoquinoxaline ( 4 ) with thionyl chloride or selenium oxychloride gave [1,2,5]thiadiazolo-[3,4-b]quinoxaline ( 21 ) and [1,2,5]selenadiazolo[3,4-b]quinoxaline ( 22 ), respectively. Sulfurous acid reduced 21 to the 4,9-dihydro derivative 23 , which was reoxidized to 21 with chloranil. Aqueous hase hydrolyzed 21 to 4 via the hydrated intermediate 24 . Aqueous glyoxal cyclized 4 to the covalent hydrate of pyrazino[2,3-b]quinoxaline ( 26 ), 27 , which was dehydrated to 26 . Compound 26 underwent rapid addition of two alcohols in a process analogous to covalent hydration.     

2,5-二乙氧甲酰氨基-1,3,4-噻二唑超分子化合物的合成和晶体结构

报道了一种用1,6-二取代二硫脲在DMF中加热回流直接脱H₂S关环合成2,5-二取代1,3,4-噻二唑类化合物的新方法, 并用此方法合成了2,5-二乙氧甲酰氨基-1,3,4-噻二唑. 用元素分析、核磁共振氢谱、红外光谱进行了表征, 用X射线单晶衍射法确定了其单晶结构. 晶体属单斜晶系, P2₁/c空间群, a＝1.0093(4) nm, b＝0.9035(4) nm, c＝1.2924(6) nm, β＝96.785(9)°, V＝1.1703(9) nm³, Z＝4, D_c＝1.477 g/cm³, F(000)＝544, μ＝0.287 mm^－1. 该化合物通过分子间氢键形成了一种二维网状结构的超分子, 由于分子间的作用力使其分子又沿c轴呈层状堆积.     

Convenient synthesis of α,β-unsaturated sulfones via a Mizoroki-Heck reaction of arylboronic acids with phenyl vinyl sulfones

Palladium acetate catalyzed Mizoroki-Heck reaction of arylboronic acids with phenyl vinyl sulfones afford α,β-unsaturated sulfones in good yields.     

原位掺杂法制备氮掺杂中孔炭及乙炔氢氯化反应性能

聚氯乙烯(PVC)是世界五大工程塑料之一,在工业、农业、建筑、电力及通信等领域有着非常广泛的应用.氯乙烯(VCM)作为合成 PVC的单体,其生产工艺以源于煤化工路线的乙炔氢氯化法工艺为主,但是该工艺目前采用的是氯化汞催化剂,存在较为严重的环境污染问题.开发新型无汞催化剂成为电石法生产 VCM亟待解决的问题.氮掺杂炭基非金属催化剂成本低廉,制备简单,在诸多反应中展现了较好的性能,成为近几年多相催化领域的一个研究热点,在乙炔氢氯化反应中也具有较好的活性,但是对活性中心的鉴别及制备方法的研究还有待深入.本文报道了一种一步原位尿素掺杂氮的中孔炭的制备方法,采用氮气吸附-脱附、高分辨透射电子显微镜、元素分析和X射线光电子能谱(XPS)等表征手段研究了氮掺杂中孔炭的结构、氮含量及存在形式,并与两步尿素改性方法做了对比,探究了氮掺杂形式与中孔炭乙炔氢氯化反应性能之间的关系,同时考察了尿素用量对氮掺杂中孔炭的氮含量和存在形式的影响.元素分析结果表明,原位合成法能有效地将氮掺杂进骨架中,随着制备过程中尿素用量增加,得到的氮掺杂中孔炭中的氮含量增加,可达3.6 wt%.后处理法的掺氮效果较差,材料氮含量仅为0.2 wt%. XPS测试进一步表明,一步法原位法可以得到石墨型氮占据主导地位的氮掺杂中孔炭,石墨型氮约占70%左右,后处理制备的氮掺杂中孔炭中石墨氮、吡啶氮和吡咯氮三种形式含量相差不大.对不同方法合成的氮掺杂介孔炭的乙炔氢氯化反应催化性能进行了评价,结果显示,无论是原位合成还是后处理制备的氮掺杂中孔炭,其活性均比中孔炭得到一定提升.氮的引入能有效提高材料的乙炔氢氯化反应性能.原位合成法制备的氮掺杂中孔炭在乙炔氢氯化反应中的催化性能远高于后处理法.对于原位合成的氮掺杂中孔炭,在一定范围内,随着氮含量的增加,催化活性提高,但当尿素用量过高时,虽然氮含量增加,催化活性却有所下降,这归因于孔结构坍塌和比表面积下降.     

Water mediated efficient one-pot synthesis of bis-(4-hydroxycoumarin)methanes

Abstract

Manganous chloride (MnCl₂·4H₂O) has been used as an efficient catalyst for an improved and rapid one-pot synthesis of bis-(4-hydroxycoumarin)methanes in excellent yields using water as a reaction medium. This aqueous mediated reaction of various aromatic and heteroaromatic aldehydes with 4-hydroxycoumarin using catalytic amounts of manganous chloride avoids the use of expensive, corrosive reagents, toxic solvents, and provides operational simplicity.     

醋酸碘苯促进的氧化反应在构建2-氨基-1,3,4-噻二唑分子中的应用

报道了一种用高价碘试剂促进缩氨基硫脲分子内氧化偶联反应,能够有效地合成2-氨基-1,3,4-噻二唑类衍生物.高价碘可以作为温和的反应试剂,拥有毒性低、廉价可循环易操作的特性.该反应具有原料易制得、操作简便以及较好的底物适用性等特点.反应机理也进行了初步研究.     

Intramolecular amidation: synthesis of novel imidazo[2,1-b][1,3,4]thiadiazole and imidazo[2,1-b][1,3]thiazole fused diazepinones

Novel heterocyclic systems 2-alkyl/aryl-9-(2-hydroxybenzylidene)-7,9-dihydro-8H-[1,3,4]thiadiazolo[2′,3′:2,3]imidazo[4,5-d][1,2]diazepin-8-one and 9-(2-hydroxy-benzylidene)-3,3-dimethyl-3,4,7,9-tetrahydro-2H-11-thia-4b,6,7,10-tetraazaindeno[1,2-a]azulene-1,8-dione are synthesized via an intramolecular amidation reaction. An interesting ring opening and cyclization of 2-alkyl/aryl-6-(2-oxo-2H-chromen-3-yl)imidazo[2,1-b][1,3,4]thiadiazole-5-carbaldehyde and 6,6-dimethyl-8-oxo-2-(2-oxo-2H-chromen-3-yl)-5,6,7,8-tetrahydroimidazo[2,1-b][1,3]benzothiazole-3-carbaldehyde are discussed.     

Pd-Catalyzed enantioselective synthesis of 2-methyl-3-methyleneindoline

A Pd-catalyzed enantioselective synthesis of 2-methyl-3-methyleneindoline in up to 89% yield and 84% ee from racemic vinyl benzoxazinanones has been developed with the help of(R,R)-BenzP*ligand.Mechanism studies support the formation of palladacyclobutane as the key intermediate via C2 attack to π-allyl Pd complex.The β-hydride elimination provides a new reaction pathway for the palladacyclobutane.     

凝胶点前氯乙烯－邻苯二甲酸二烯丙基酯共聚物表征，支化度模型及悬挂双键活性

根据单烯－二烯自由基共聚合反应特点，提出一种新的支化点对分子量的分布模型，讨论了用凝胶色谱－特性粘数法表征文化聚合物时，文化点对分子量分布和式［η］０，ｂ／［η］０．１＝ｇ０中的指数ｃ对结果的影响．建立了氯乙烯－二烯类单体悬浮聚合凝胶点前的平均支化度模型．用凝胶点前平均文化度和平均分子量模型拟合实验结果发现：ａ．新的支化分布模型更合理，且ｃ＝０．７２；ｂ．悬挂双键活性下降一个数量级；ｃ．对本文样品，特性粘数和分了量仍符合Ｍａｒｋ－Ｈｏｕｗｉｎｋ方程，［η］＝０．２３５７Ｍ￣０．５２７．     

2-氨基-5-(2-氯吡啶-4-基)-1,3,4-噻二唑衍生物的合成及生物活性

酰胺;2-氨基-5-(2-氯吡啶-4-基)-1;3;4-噻二唑衍生物的合成及生物活性     

3-(3’-吡啶基)-6-芳基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑衍生物基态和激发态性质

用密度泛函B3LYP方法对3-(3’-吡啶基)-6-芳基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑衍生物(芳基为苯基、3-吡啶基和苯乙烯基)进行基态几何构型全优化, 计算分子的电离势IP和电子亲和势EA等相关能量, 并用Zerner间略微分重叠(ZINDO)和含时密度泛函(TDDFT)方法计算吸收光谱, 用单组态相互作用方法(CIS)优化三种化合物分子的S1激发态结构, 分析其能量与发射光谱的关系, 计算溶剂中分子的吸收和发射光谱, 并与实验结果对照. 计算结果表明, 从3-(3’-吡啶基)-6-苯基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑分子(化合物A)到3-(3’-吡啶基)-6-(3’-吡啶基)-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑分子(化合物B)以及3-(3’-吡啶基)-6-对乙烯苯基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑分子(化合物C)的电子亲和势依次增大, 愈来愈容易接受电子, 吸收光谱和发射光谱红移.     

Synthesis,structural characterization,and catalytic reactivity of a new molybdenum(VI) complex containing 1,3,4-thiadiazole derivative as a tridentate NNO donor ligand

A new cis-dioxo molybdenum(VI) complex was obtained by reaction of 2,4-dihydroxybenzylidene(5-N,N-methylphenylamino-1,3,4-thiadiazol-2-yl)hydrazone as ligand and [MoO₂(acac)₂] in methanol and was characterized by elemental analyses, ¹H NMR, IR, and electronic spectroscopic studies. The complex was also analyzed by single-crystal X-ray diffraction. The structure determination revealed a distorted octahedral coordination geometry around molybdenum in which the tridentate NNO donor (L^2–) is bonded to [MoO₂]²⁺ through phenolic oxygen, hydrazinic nitrogen, and thiadiazole nitrogen. The sixth coordination site is occupied by a weakly bonded methanol. The complex was tested as a catalyst for homogeneous epoxidation of olefins using tert-butyl hydrogen peroxide as an oxidant. In the homogeneous catalytic system, the reactions are efficiently carried out with high yields and selectivity.     

CuCl-catalyzed cycloaddition of 1,3-butadiynes with primary amines: an atom-economic process for synthesis of 1,2,5-trisubsituted pyrroles

1,3-Butadiynes underwent inter- and intramolecular double hydroamination with primary amines in the presence of CuCl at 100 °C to afford 1,2,5-trisubsituted pyrroles in good to high yields.     

Iodine catalyzed efficient synthesis of symmetrical diaryl sulfoxides from arenes and thionyl chloride under solvent-free conditions

Synthesis of symmetrical diaryl sulfoxides from arenes and thionyl chloride in the presence of a catalytic amount of iodine at room temperature under solvent-free conditions is described.Mild reaction conditions,easy workup,high yield,and easily available catalyst are important features of this method.