二硼试剂参与的含氟异喹啉衍生物的简便合成

本文探究了一种二硼试剂参与的自由基交叉偶联反应,用于合成含氟的四氰异喹啉分子骨架。合成路线的起始原料是二苄胺和3-溴丙烯,经亲核取代反应后,在二硼试剂和溴化镍的双催化作用下发生环化反应,成功合成了3-(2-苄基-1,2,3,4-四氢异喹啉-4-基)-2,2-二氟丙酸乙酯。自由基引发的级联环化是一种合成复杂环状有机物的有效途径。该合成路线的起始原料价廉易得,合成步骤简便,清洁易操作,条件较温和,可十分简便地合成含氟异喹啉衍生物,为喹啉的研究提供了新思路。     

含吡啶基的HBC衍生物的合成

以四芳基取代环戊二烯酮2与二烷基取代的二苯乙炔3通过Diels-Alder环加成反应得到六芳基取代苯4。化合物4在路易斯酸催化下通过Scholl环氧化脱氢反应,生成化合物5,5再与4-硼酸吡啶发生Suzuki偶联反应生成目标化合物1。     

三芳基胺自由基正离子盐衍生物的合成

三芳基胺自由基正离子六氯锑酸盐是常用的单电子氧化剂,被广泛应用于引发电子转移反应。与其他氧化剂相比具有氧化能力强、毒性小、制备简单、易于从反应体系中除去等优点。本文用4-卤代苯胺、4-碘甲苯为原料,1,10-菲啰琳为配体,氯化亚铜为催化剂,甲苯为溶剂,通过偶联反应合成了一系列三芳基胺衍生物,进而制备了几种新型自由基正离子盐。该方法具有产率高,条件温和的优点。目标化合物的结构经氢谱进行了表征。     

间氨基苯酚N-烷基衍生物的合成新方法

开发了一种合成间氨基苯酚N-烷基衍生物的新方法。以间二硝基苯与过量的苯甲醇在碳酸钾的存在下发生亲核取代反应,生成的产物(间硝基苄基苯酚)不分离,直接转移到压力釜中,添加乙醛或正丁醛,经氢化-裂解-还原-胺化反应得到间氨基苯酚N-烷基衍生物,同时副产甲苯。整个反应过程不需要用水。     

Preparation of poly(isobutylene-b-tert-butyl acrylate) by transformation of living carbocationic polymerization into radical polymerization

用聚合转化法合成聚异丁烯-聚丙烯酸叔丁酯嵌段聚合物何金太1,2,任天瑞1,程斌2(1.中国科学院过程工程研究所生化工程国家重点实验室,北京100080;2.北京化工大学北京市新型高分子材料制备与加工重点实验室,北京100029)使用BCl3/CH2Cl2/DTBP/IB反应体系实现了异丁烯的正离子聚合,得到末端为硼氧烷基的聚异丁烯,其与苯基溴化镁发生金属转移反应,生成末端为二苯基硼烷的聚异丁烯,其在常温下与氧气发生氧化反应,生成碳氧自由基,从而引发丙烯酸叔丁酯的自由基聚合,得到异丁烯和丙烯酸叔丁酯的嵌段聚合物。     

用聚合转化法合成聚异丁烯-聚丙烯酸叔丁酯嵌段聚合物

使用BCl3/CH2Cl2/DTBP/IB反应体系实现了异丁烯的正离子聚合,得到末端为硼氧烷基的聚异丁烯,其与苯基溴化镁发生金属转移反应,生成末端为二苯基硼烷的聚异丁烯,其在常温下与氧气发生氧化反应,生成碳氧自由基,从而引发丙烯酸叔丁酯的自由基聚合,得到异丁烯和丙烯酸叔丁酯的嵌段聚合物.     

二烯酮类化合物在构建复杂有机化合物中的应用

二烯酮作为一类具有多个化学反应位点的不饱和酮类化合物,可与多种反应底物实现不同类型的化学转化,高效快捷地构建功能各异的有机化合物。该文综述了近些年二烯酮类化合物与多种反应底物的化学转化。首先,探讨了2,5-环己烯酮类化合物与不同试剂的串联Michael-Smiles环丙烷化反应、环加成反应、三组分Ritter反应、光化学重排反应和氧化偶联反应分别构建了环丙烷类衍生物、氮杂螺环类衍生物、含氟烷基N,O-缩酮类衍生物、稠环吲哚类化合物、酰胺类化合物和不对称联芳烃类化合物。接着,分析了1,4-戊二烯-3-酮类化合物与丙二腈(硝基甲烷)、硫氢化钠、氧化吲哚、吡唑酮、芴和巴比妥酸双Michael加成反应,分别合成了多取代环己酮类化合物、二芳基噻喃酮类化合物、螺环氧化吲哚类化合物、螺环吡唑酮类化合物、螺环芴类化合物和螺环巴比妥类衍生物。然后,介绍了2,4-戊二烯-1-酮类化合物的1,4-共轭加成、氮杂Michael加成反应、分子内Morita-Baylis-Hillman (MBH)反应、分子内还原Aldol反应、分子内Aldol反应和分子内[4+2]环加成/氧化反应分别实现了有机含硫化合物、有机含氮化合物、多取代茚酮类化合物和SGLT2抑制剂——托格列净关键中间体的制备。最后,对二烯酮在后续化学反应中的潜在应用进行了展望。     

4-甲基-7-羟基香豆素抗氧化性能研究

以间苯二酚为原料，在酸催化下与乙酰乙酸乙酯发生取代、环化脱水反应，得到4-甲基-7-羟基香豆素(1)，化合物1再经酯化获得4-甲基-7-乙酰氧基香豆素(2)，通过核磁共振氢谱（nuclear magnetic resonance hydrogen spectroscopy，1HNMR）、核磁共振碳谱（nuclear magnetic resonance carbon spectroscopy，13CNMR）和超高效液相色谱-电喷雾离子源质谱联用仪（ultra high performance liquid chromatograph electrospray ion source mass spectrometer，UHPLC-ESI-MS）对合成产物结构进行了表征。采用多种自由基氧化DNA的反应体系来检测化合物的抗氧化活性，其中包括抑制2,2’-偶氮二异丁基脒二盐酸盐(2,2’-azobis(2-amidinopropanehydrochloride)，AAPH)、HO?、Cu2 /还原型谷胱甘肽(glutathione，GSH)引发的DNA氧化反应。此外，还通过淬灭自由基体系，探索了化合物还原自由基的能力，其中自由基包括2,2′-偶氮-双-(3-乙基苯并噻唑啉-6-磺酸)二铵盐自由基(2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical，ABTS ?)、二苯苦味酰肼自由基(2,2’-diphenyl-1-picrylhydrazyl，DPPH)、2,6-二叔丁基-(3,5-二叔丁基-4-氧代-2,5-环己二烯)-对-甲苯氧(galvinoxyl)自由基，进而探究羟基对香豆素抗氧化性能的影响。结果表明：1）化合物1不仅能够很好地抑制AAPH、HO?、Cu2 /GSH自由基引发的DNA氧化反应，也能够捕获ABTS ?、DPPH、galvinoxyl自由基；2）化合物2仅能够抑制HO?和Cu2 /GSH自由基引发的DNA氧化反应，捕获ABTS ?和DPPH两种自由基。3）化合物1抑制自由基引发的DNA氧化反应活性和捕获自由基能力均优于化合物2，说明化合物1具有较强自由基的清除能力和还原能力，是一种潜在的抗氧化剂。     

吡嗪-噁唑联芳类化合物的合成及其抗氧化性能

为了从吡嗪和噁唑类化合物中寻找新的抗氧化剂，本文采用FeCl3催化吡嗪-N-氧化物和噁唑化合物发生氧化偶联反应，合成了3个吡嗪-噁唑联芳类化合物。采用1HNMR、13CNMR和MS对目标化合物的结构进行了表征；通过抑制自由基引发的DNA氧化反应及淬灭自由基反应体系对化合物的抗氧化活性和还原能力进行了测试。结果表明，3个目标化合物能够有效地抑制自由基引发的DNA氧化反应并捕获自由基，具有较强的自由基清除能力和还原能力，是一类潜在的抗氧化剂。其中，在抑制2,2''-偶氮二异丁基脒二盐酸盐(AAPH)引发的DNA氧化反应体系中，3个吡嗪-噁唑联芳类化合物的有效计量因子(n)分别为1.48、1.78和1.88; 在抑制HO?和还原型谷胱甘肽自由基(GS?)引发的DNA氧化反应体系中，3个化合物相对空白硫代巴比妥酸活性物质(TBARS)吸光度百分数分别为76.1%和68.3%、69.8%和64.1%及72.6%和67.4%；3个化合物均能够捕获2,2''-偶氮-双-(3-乙基苯并噁唑啉-6-磺酸)二铵盐自由基(ABTS ?)和二苯苦味酰肼自由基(DPPH?)。     

二烯酮类化合物在构建复杂有机化合物中的应用

二烯酮作为一类具有多个化学反应位点的不饱和酮类化合物，可与多种反应底物实现不同类型的化学转化，高效快捷地构建功能各异的有机化合物。该文综述了近些年二烯酮类化合物与多种反应底物的化学转化，首先探讨了2,5-环己烯酮类二烯酮与不同试剂的串联Michael-Smiles环丙烷化反应、环加成反应、三组分Ritter反应、光化学重排反应和氧化偶联反应分别构建了环丙烷类衍生物、含氟烷基N,O-缩酮类衍生物、稠环吲哚类化合物、酰胺类化合物和不对称的联芳烃类化合物，接着分析了1,4-戊二烯-3-酮类二烯酮与丙二腈（硝基甲烷）、硫氢化钠、氧化吲哚、吡唑酮、芴和巴比妥酸双Michael加成反应，分别合成了多取代环己酮类化合物、二芳基噻喃酮类化合物、螺环氧化吲哚类化合物、螺环吡唑酮类化合物、螺环芴类化合物和螺环巴比妥类衍生物，然后研究了2,4-戊二烯-1-酮类二烯酮的1,4-共轭加成、氮杂Michael加成反应、分子内MBH反应、分子内还原Aldol反应、分子内Aldol反应和分子内[4+2]环加成/氧化反应分别实现了有机含硫化合物、有机含氮化合物、多取代茚酮类化合物和SGLT2抑制剂——托格列净关键中间体的制备，最后对二烯酮在后续化学反应中的潜在应用进行了展望。     

Polymerization of styrene and cyclization to macrocyclic polystyrene in a one-pot,two-step sequence

Dibrominated polystyrene (BrPStBr) was produced by atom transfer radical polymerization (ATRP) at 80 °C, using the bifunctional initiator benzal bromide to afford the telechelic precursor. The ATRP reaction was stopped around 40% monomer conversion and directly converted into an radical trap-assisted atom transfer radical coupling (RTA-ATRC) reaction by lowering the temperature to 50 °C, and adding the radical trap 2-methyl-2-nitrosopropane (MNP) along with additional catalyst, reducing agent, and ligand to match ATRC-type reaction conditions. In an attempt to induce intramolecular coupling, rather than solely intermolecular coupling and elongation, the total reaction volume was increased by the addition of varying amounts of THF. Cyclization, along with intermolecular coupling and elongation, occurred in all cases, with the extent of ring closure a function of the total reaction volume. The cyclic portion of the coupled product was found to have a 〈G〉 value around 0.8 by GPC analysis, consistent with the reduction in hydrodynamic volume of a cyclic polymer compared to its linear analog. Analysis of the sequence by ¹H NMR confirmed that propagation was suppressed nearly completely during the RTA-ATRC phase, with percent monomer conversion remaining constant after the ATRP phase.     

Oxidation of 2,6-di-tert-butylphenols to Diphenoquinones Catalysed by Schiff Base-Cu(II) Systems Immobilized on Polymer Support

Benzoquinone, diphenoquinones and its derivatives are important intermediates for industrial synthesis of a wide variety of special chemicals, such as pharmaceuticals, dyes and agricultural chemicals. The useful catalyst were obtained by aminolysis of vinylbenzyl chloride/divinylbenzene copolymer with ethylenediamine (1) or urotropine (2) and then modification by salicylaldehyde (1A, 2A) or picolinaldehyde (1B, 2B). The catalytic activity of Cu(II) complexes with Schiff base immobilized on the synthesized supports were tested in the oxidation reaction of 2,6-di-tert-butylphenol (DTBP) to diphenoquinone (PQ) with tert-butylhydroperoxide. The best oxidation degree of DTBP (60-70%) and the selectivity towards PQ (80%) is revealed by Cu(II) complexes with long Schiff base ligands derived from salicylaldimine (1A), which have CuL structure (EPR measurement).     

Study of the coupling reactions between electrochemically generated aromatic radical anions and methyl, alkyl and benzyl radicals

Alkyl radicals produced in the indirect reduction of alkyl halides or alkyldimethylsulfonium salts by electrochemically generated aromatic radical anions couple fast with the latter and alkylated or dialkylated dihydro compounds are formed. Rate constants measured for the coupling reaction between on one hand methyl, primary, secondary and tertiary alkyl radicals as well as benzyl and cumyl radicals and on the other hand a wide spectrum of electrochemically generated aromatic radical anions are found to be about 1×10⁹ M⁻¹ s⁻¹. Previous measurements of coupling rate constants for primary alkyl radicals have been re-evaluated since they were affected by the presence of an S_N2 reaction occurring between the alkyl halides used as radical precursors and the aromatic radical anions. New experiments are also included using alkyldimethylsulfonium salts as precursors in order to prevent such S_N2 artefacts. It is concluded that sterical hindrance does not play a significant role for the radical-radical anion coupling reactions. In general the rate constants for the coupling reactions are all close to 10⁹ M⁻¹ s⁻¹.     

One pot,two step sequence converting atom transfer radical polymerization directly to radical trap-assisted atom transfer radical coupling

Monobrominated polystyrene (PStBr) chains were prepared using standard atom transfer radical polymerization (ATRP) procedures at 80 °C in THF, with monomer conversions allowed to proceed to approximately 40%. At this time, additional copper catalyst, reducing agent, and ligand were added to the unpurified reaction mixture, and the reaction was allowed to proceed at 50 °C in an atom transfer radical coupling (ATRC) phase. During this phase, polymerization continued to occur as well as coupling; expected due to the substantial amount of residual monomer remaining. This was confirmed using gel permeation chromatography (GPC), which showed increases in molecular weight not matching a simple doubling of the PStBr formed during ATRP, and an increase in monomer conversion after the second phase. When the radical trap 2-methyl-2-nitrosopropane (MNP) was added to the ATRC phase, no further monomer conversion occurred and the resulting product showed a doubling of peak molecular weight (M_p), consistent with a radical trap-assisted ATRC (RTA-ATRC) reaction.     

原子转移自由基偶联法合成星形聚合物

以卤端基聚合物为大分子引发剂,卤化亚铜／２,２‘＝二联二吡啶为催化剂,工业二乙烯基苯、纯间－二乙烯基苯、纯对－二乙烯基苯为偶联剂合成了一系列星形聚合物。研究了偶联反应的影响因素。结果表明,反应体系产生凝胶的趋势随着二乙烯基苯与预聚物配比的增加而增加;偶联反应速度随着反应物总浓度的增加而加大;提高反应温度有利于提高偶联效率;以低单体转化率下合成的预聚物为大分子引发剂时的偶联效率高于高单体转化率下合成     

纳米尺度AgBr/I乳剂颗粒的光电子衰减行为

本文以鱼明胶为保护介质,在不同的鱼明胶 溴化银比值下,采用双注法制备AgBr/I纳米颗粒乳剂,以TEM观测颗粒形态,据此统计得出该乳剂中AgBr/I纳米颗粒平均粒径(d)及粒径分布系数(|±σ|/d).鱼明胶 溴化银比值在0.31g/mmol—0.62g/mmol范围内,颗粒平均粒径仅有微小变化,但粒径分布系数随该比值的增大而减小,表明颗粒均一性提高.采用微波光导法对该纳米尺度AgBr/I乳剂颗粒的光电子衰减过程进行测试,结果表明,纳米尺度Ag Br/I乳剂颗粒的光电子衰减过程为双组分,即初始快衰减和随后慢衰减,其衰减过程皆符合一级动力学规律.该纳米尺度乳剂颗粒光电子寿命较常规乳剂颗粒明显缩短.     

纳米尺度AgBr／Ⅰ乳剂颗粒的光电子衰减行为

本文以鱼明胶为保护介质,在不同的鱼明胶 溴化银比值下,采用双注法制备AgBr/I纳米颗粒乳剂,以TEM观测颗粒形态,据此统计得出该乳剂中AgBr/I纳米颗粒平均粒径(d)及粒径分布系数(|±σ|/d).鱼明胶 溴化银比值在0.31g/mmol—0.62g/mmol范围内,颗粒平均粒径仅有微小变化,但粒径分布系数随该比值的增大而减小,表明颗粒均一性提高.采用微波光导法对该纳米尺度AgBr/I乳剂颗粒的光电子衰减过程进行测试,结果表明,纳米尺度Ag Br/I乳剂颗粒的光电子衰减过程为双组分,即初始快衰减和随后慢衰减,其衰减过程皆符合一级动力学规律.该纳米尺度乳剂颗粒光电子寿命较常规乳剂颗粒明显缩短.     

Li~+/MgO上交叉偶联作用的研究

采用Li+/MgO催化剂研究了Li含量、反应温度、原料气组成对甲烷和甲苯催化氧化交叉偶联成乙苯或苯乙烯 (即C8)反应的影响 ,对几种Li含量催化剂上各影响因素引起的差异进行了考察。结果表明 ,其活性中心也主要是Li+O- ,合适的L酸点是本交叉偶联反应中反应物的吸附中心 ,Li+O- 和L酸点是决定偶联反应产物C2 和C8的主要因素。偶联可能主要按游离基机理进行     

Curing of unsaturated polyester resins: Effect of surface treatment of particulates

The effect of surface treatment of particulates on the curing kinetics of unsaturated polyester resin has been investigated using a differential scanning calorimeter. Two coupling agents, γ-methacryloxy propyltrimethoxy silane (γ-MPS) and phenyltriethoxy silane (PTS), were employed. The former reacted with the resin; the latter did not. A kinetic model of free radical addition polymerization was used. A correction factor was used to represent the effective free radical concentration in order to account for the formation of charge transfer complex between the glass beads and the free radicals in the resin. The results indicate that (1) the resin with treated particulates showed generally faster reaction rate and conversion than the resin with untreated particulates; (2) no obvious difference on the curing kinetics was observed between these two coupling agents; the primary role of coupling agent is to inhibit the influence of particulates on the curing kinetics of the resin by effective surface coverage; and (3) a minimum aqueous concentration of 0.05 wt% was suggested for surface treatment of particulates; the reaction rate of the resin was slightly improved when the concentration of the coupling agent was 0.01 wt%; this might possibly be due to insufficient coverage of the particulate surface.     

蒽环与苯环间的光化学Ⅲ．9-（苯基氧甲基）蒽的合成及其光化学反应

对苯二酚和间苯二酚1分别与氯化苄反应生成单醚2，2与9-氯甲基蒽反应生成含有苯环和蒽环的9-(苯基氧甲基)蒽3，3在光照下发生裂解和重排，最后生成蒽环和蒽环间的光致环加成产物biplanene 4和lepidopterene 5。