3-乙氧羰基-2,3/2,5-二氢-1,5-苯并硫氮杂卓的互变异构及其热行为

用核磁共振法研究了3-乙氧羰基-2,3/2,5-二氢-1,5-苯并硫氮杂卓（亚胺型杂卓4/烯胺型杂卓5）在氘代甲醇（CD3OD）、苯（C6D6）、三氯甲烷（CDCl3）和二甲基亚砜（DMSO-d6）四种不同极性溶剂中的互变异构.结果表明,无水条件下,亚胺型杂卓4和烯胺型杂卓5在非质子溶剂中不发生相互转化,而在质子溶剂中,亚胺型杂卓4不稳定,部分转化成其异构体—烯胺型杂卓5;基于杂卓4和5在DMSO和CHCl3中的紫外光谱有良好的区分度,用紫外光谱法研究了在DMSO及CHCl3（低温时）中溶液的温度、酸碱度对其互变异构的影响,发现上述异构体在不同温度下均很稳定,并且对弱酸、弱碱稳定.然而,随着溶液酸性的增强,杂卓4向杂卓5快速转化,而在强碱中两种异构体均发生分解.用TG/DSC技术、Kissinger法和Ozawa-Doyle法考察了上述异构体的热稳定性以及第一步分解过程的非等温动力学,确定了分解反应动力学参数（活化能E和指前因子A）及DTG峰温处的热力学参数（△G≠,△H≠,△S≠）.     

三羟甲基氨基甲烷水杨醛类席夫碱质子转移异构化的理论研究

采用密度泛函(DFT)中的B3LYP方法,在6-311+G(d,p)基组水平上对三羟甲基氨基甲烷水杨醛席夫碱气相、水溶剂及甲醇溶剂中的分子内质子转移和衍生席夫碱的互变异构反应机理进行了计算研究,获得了反应焓、活化能、活化吉布斯自由能和质子转移反应的速率常数等参数.液相计算采用Onsager模型.结果表明,不论在气相、水溶剂还是甲醇溶剂中,三羟甲基氨基甲烷水杨醛席夫碱(L3=H,L5=H)烯醇亚胺式异构体R1和醌型的酮烯胺异构体P1可以共存,但以苯环型的烯醇亚胺式R1为主要形式.当由苯环型的烯醇亚胺R1向醌型的酮烯胺P1分子内质子转移时活化能较低,室温常压下反应容易进行.水和甲醇溶剂对异构化反应影响较小.当—NO2,—OMe取代生成衍生席夫碱时(L3=H,L5=NO2;L3=OMe,L5=H),结果表明,苯环型的烯醇亚胺式和醌型的酮烯胺式异构体都能共存,质子转移异构化反应的活化能垒也较低.     

3-乙酰基-2,3/2,5-二氢-1,5-苯并硫氮杂卓的选择性合成及其互变异构

研究了温度、时间等因素对合成反应的影响, 发现亚胺型杂卓4和烯胺型杂卓5分别为速度控制产物和平衡控制产物, 并且实现了两种互变异构体的选择性合成. 用核磁共振法研究了溶剂、酸碱度对4, 5互变异构的影响, 发现两种异构体在CD₃OD, DMSO-d₆, C₆D₆以及精制的CDCl₃中比较稳定, 在未精制的CDCl₃中容易发生互变及开环反应, 形成3, 4, 5的平衡混合物, 并以4为主要组分. 4, 5在酸中不稳定, 但在弱碱(吡啶)中能稳定存在. 采用密度泛函理论方法在B3LYP/6-31G基组水平上对四组(八种)不同取代基的上述异构体进行了几何优化和计算. 结果表明, 烯胺型杂卓5比亚胺型杂卓4稳定, 理论计算结果与实验结果基本一致.     

过氧化氢与苯乙烯环氧化的反应机理及溶剂效应

以过氧化氢与苯乙烯环氧化为模型反应, 采用Materials Studio软件中Dmol³模块, 模拟计算了过氧化氢与苯乙烯的环氧化反应机理. 并用连续介质-类导体屏蔽模型(COSMO)研究了反应体系分别在三种质子性溶剂(水, 乙醇, 叔丁醇)中的溶剂化效应. 为研究溶剂分子直接参与反应的微观过程, 用离散介质模型模拟了单个水分子、乙醇分子和叔丁醇分子分别对反应的影响. 两种溶剂模型所得的结果一致, 叔丁醇作溶剂时反应活性最好, 乙醇次之; 质子性溶剂能够促进过氧化氢分子的异裂, 形成活性氧物种, 从而使反应能垒降低.     

有机溶剂对PEM燃料电池CCM结构和性能的影响

采用直接喷涂法将催化剂涂覆在质子交换膜上形成CCM(catalyst coated membrane),CCM与碳纸扩散层组成膜电极用于质子交换膜燃料电池.制备CCM的混合液由质量分数20%的Pt/C催化剂、质量分数5%的Nafion溶液、有机溶剂和水组成.不同的有机溶剂(乙醇、异丙醇和叔丁醇)、有机溶剂的含量、溶剂的...     

钛硅分子筛催化1-丁烯环氧化反应溶剂效应和酸碱效应研究

研究了用双氧水为氧化剂，钛硅分子筛TS-1催化1-丁烯环氧化反应的溶剂效应．研究发现，在质子性溶剂中1-丁烯环氧化反应活性高于非质子性溶剂，而以甲醇为溶剂H2O2转化率最高．分别利用碱性添加物稀氨水溶液和酸性添加物稀盐酸溶液调变反应介质的pH值，考察了介质的pH值对1-丁烯环氧化反应的影响，结果表明，随pH值提高，1，2-环氧丁烷(B0)的选择性略提高，但是过量稀氨水的加入会导致催化剂失活，双氧水的转化率及利用率明显下降．与钛硅分子筛催化丙烯环氧化相比，酸性添加物的加入对反应结果的影响不大，随反应介质的pH值降低1，2-环氧丁烷的选择性没有明显下降．     

RuPHOX-Ru催化的手性γ-氨基醇的不对称氢化合成

研究了双反应活性中心手性二茂钌催化剂RuPHOX-Ru催化的一系列潜手性β-酰亚胺酮的不对称氢化反应.在优化的反应条件下(无水Na2CO3为碱,乙醇为溶剂),几乎所有的反应都可定量地转化为相应的手性γ-酰亚胺醇产物,且产物的对映选择性最高可达98%ee.产物的结构进行了充分的表征,且绝对构型也得到了确认.报道的β-酰亚胺酮的不对称氢化反应不仅简洁高效,且产物可通过简单的转化得到一系列手性γ-伯胺醇.     

伯胺N1923萃取钼的机理研究

通过等摩尔系列法、摩尔比法、饱和法以及有机相的红外光谱等研究了伯胺N1923从中性溶液和伯铵盐从酸性溶液萃取Mo(Ⅳ)的机理,结果表明,伯胺从中性溶液萃取Mo(Ⅳ)按溶剂化历程进行,伯铵盐从酸性溶液萃取Mo(Ⅳ)是阴离子交换反应。     

配合物的生成热与配位体的加质子热之间的直线焓关系——Cu(Ⅱ)-N-(对位取代苯基)氨基乙酸体系

使用RD-Ⅰ型热导式自动量热计测量N-(对位取代苯基)氨基乙酸的加质子热及其与Cu(Ⅱ)生成配合物的生成热,首次用量热法从实验上验证了配合物的生成热与配位体的加质子热之间存在如下的直线焓关系式:△H_(ML)=Q—β△H_(HL),式中:△H_(ML)为配合热,△H_(HL)为加质子热,Q和β为常数。     

aza-Morita-Baylis-Hillman反应二次串联构建氨基衍生的1,6-二烯化合物

aza-Morita-Baylis-Hillman反应是一类非常重要的构建C—C键的人名反应,被广泛应用于合成化学和药物化学领域.报道了一类新颖的1,4-二氮杂二环[2.2.2]辛烷(DABCO)介导的二次aza-Morita-Baylis-Hillman串联反应.该反应利用伯胺与甲醛能原位生成亚胺正离子的特征,在甲苯与水的混合溶剂中,实现了DABCO诱导的缺电子烯烃与亚胺正离子间的二次Mannich反应,最终以中等到良好的产率获得了一系列氨基衍生的1,6-二烯化合物.实验结果显示该三组分反应体系适用于一系列的苄胺、烷基胺和芳基胺底物,有效避免了传统aza-Morita-Baylis-Hillman反应对底物胺的束缚,为多样性1,6-二烯类化合物的合成提供了更加简洁的方法.     

Oxidative dissolution of copper and zinc metal in carbon dioxide with tert-butyl peracetate and a beta-diketone chelating agent

A series of beta-diketone ligands, R(1)COCH(2)COR(2) [tmhdH (R(1) = R(2) = C(CH(3))(3)); tfacH (R(1) = CF(3); R(2) = CH(3)); hfacH (R(1) = R(2) = CF(3))], in combination with tert-butyl peracetate (t-BuPA), have been investigated as etchant solutions for dissolution of copper metal into carbon dioxide solvent. Copper removal in CO(2) increases in the order tfacH < tmhdH < hfacH. A study of the reactions of the hfacH/t-BuPA etchant solution with metallic copper and zinc was conducted in three solvents: scCO(2) (supercrical CO(2)); hexanes; CD(2)Cl(2). The etchant solution/metallic zinc reaction produced a diamagnetic Zn(II) complex, which allowed NMR identification of the t-BuPA decomposition products as tert-butyl alcohol and acetic acid. Gravimetric analysis of the amount of zinc consumed, together with NMR studies, confirmed the 1:1:2 Zn:t-BuPA:hfacH reaction stoichiometry, showing t-BuPA to be an overall two-electron oxidant for Zn(0). The metal-containing products of the copper and zinc reactions were characterized by elemental analysis, IR spectroscopy, and, as appropriate, NMR spectroscopy and single-crystal X-ray diffraction [trans-M(hfac)(2)(H(2)O)(CH(3)CO(2)H) (1, M = Cu; 2, M = Zn)]. On the basis of the experimental results, a working model of the oxidative dissolution reaction is proposed, which delineates the key chemical variables in the etching reaction. These t-BuPA/hfacH etchant solutions may find application in a CO(2)-based chemical mechanical planarization (CMP) process.     

浓硫酸催化合成叔丁基苯

利用浓硫酸催化叔丁醇和苯的反应,得到叔丁基苯;利用正交法优化了反应条件,利用气相色谱法测定了产物收率.结果表明,将叔丁醇滴加到苯-浓硫酸混合溶液中,控制叔丁醇与浓硫酸物料摩尔比为1:1、苯的用量为50 mL、浓硫酸用量为8.0 mL、反应温度为50℃、搅拌时间为4 h,目标产物的收率可达62.0%.     

Condensation reactions of 3-oxo-2-arylhydrazonopropanals with active methylene reagents: formation of 2-hydroxy- and 2-amino-6-substituted-5-arylazonicotinates and pyrido[3,2-c]cinnolines via 6π-electrocyclization reactions

3-Oxo-3-phenyl-2-(p-tolylhydrazono)propanal (1a) undergoes condensation with ethyl cyanoacetate in acetic acid in the presence of ammonium acetate to yield either 2-hydroxy-6-phenyl-5-p-tolylazonicotinic acid ethyl ester (6a) or 2-amino-6-phenyl-5-ptolyl-azonicotinic acid ethyl ester (8), depending on the reaction conditions. Similarly, other 3-oxo-3-aryl-2-arylhydrazonopropanals 1a,b condense with active methylene nitriles 2c,d to yield arylazonicotinates 6b,c. In contrast, 2-[(4-nitrophenyl)-hydrazono]-3-oxo-3-phenyl-propanal (1c) reacts with ethyl cyanoacetate to yield ethyl 6-(4-nitrophenyl)-2-oxo-2,6-dihydropyrido[3,2–c]cinnoline-3-carboxylate (11), via a novel 6π-electrocyclization pathway. Finally, 3-oxo-2-(phenylhydrazono)-3-p-tolylpropanal (1d) condenses with 2a-c to yield pyridazinones 13a-c.     

Carbocation-forming reactions in dimethyl sulfoxide

Mesylate derivatives of 3-aryl-3-hydroxy-beta-lactams and thiolactams react in DMSO-d(6) by first-order processes to give alcohol products. Substituent effect studies implicate carbocation intermediates (ion-pairs) that are captured by DMSO-d(6) to give transient oxosulfonium ions. Rapid reaction of the oxosulfonium ions with trace amounts of water leads to the alcohol product and regenerates DMSO-d(6). H(2)(17)O labeling studies show that (17)O is incorporated into the DMSO. The mesylate derivatives of endo- and exo-2-hydroxy-2-phenylbicyclo[2.2.1]heptan-3-one also react in DMSO-d(6) to give the alcohol products. Ion-pair intermediates that capture DMSO giving unstable oxosulfonium ions are again proposed. Exo-2-phenyl-endo-bicyclo[2.2.1]heptyl trifluoroacetate readily eliminates trifluoroacetic acid in DMSO-d(6) via a cationic mechanism involving loss of the endo-trifluoroacetate leaving group as well as an exo-hydrogen. The O-methyl oxime derivative of alpha-chloro-alpha,alpha-diphenylacetophenone reacts in DMSO-d(6) to give 1-methoxy-2,3-diphenylindole, a product derived from cyclization of a cationic intermediate. A common ion rate suppression provides further evidence for a cationic mechanism. The triflate derivative of pivaloin reacts by a cationic mechanism in DMSO-d(6) to give rearranged products. The rate is even faster than in highly ionizing solvents such as trifluoroethanol or trifluoroacetic acid. 1-Adamantyl mesylate reacts in DMSO-d(6) by a first-order process (Y(OMs) = -4.00) to give a long-lived oxosulfonium ion, 1-Ad-OS(CD(3))(2)(+), which can be characterized spectroscopically. This oxosulfonium ion reacts only slowly with water at elevated temperatures to give 1-adamantanol. DMSO is therefore a viable solvent for k(s), k(C), and k(Delta) cationic processes.     

Reactions of sulfur- and phosphorus-substituted fluoroalkylating silicon reagents with imines and enamines under acidic conditions

Nucleophilic fluoroalkylation reactions of imines and enamines with α-phenylthio, α-phenylsulfonyl, and α-diethylphosphoryl substituted fluorinated silanes have been investigated. The reactions are promoted by hydrofluoric acid generated in situ from potassium hydrodifluoride and trifluoroacetic acid. Sulfur reagents worked well with both imines and enamines, whereas phosphorus reagent efficiently coupled only with enamines.     

Chemo- and regioselectivity in the reactions between highly electrophilic fluorine containing dicarbonyl compounds and amines. Improved synthesis of the corresponding imines/enamines

Chemo- and regioselectivity in the reactions between highly electrophilic fluorine containing dicarbonyl compounds (ethyl 4,4,4-trifluoroacetoacetate, 3,3,3-trifluoropyruvate and 1,1,1,5,5,5-hexafluoropentane-2,4-dione) and various benzylamines were systematically studied. The results obtained lead to the development of a generalized and practical method for large-scale synthesis of the corresponding imines/enamines, useful starting materials for preparation fluorinated amines and amino acid.     

Studies with polyfunctionally substituted heteroaromatics: New routes for the synthesis of polyfunctionally substituted pyridines and 1,2,4-triazolo[1,5-a]pyridines

The 1-substituted ethylidenemalononitriles 1a–c condensed with triethyl orthoformate in refluxing acetic anhydride to yield the dienes 2a–c . On the other hand, a mixture of N,N-dimethylformamide and triethyl orthoformate condensed with 1a–d to yield the N,N-dimethylaminopentadienonitriles 2d–g . The pentadienonitriles 2d–g were also formed from the reaction of 1a–d with dimethylformamide dimethylacetal in refluxing acetic acid. When compounds 1a–c were treated with dimethylformamide dimethylacetal in refluxing p-xylene, a mixture of 3 , 4 and 2e–g was formed. The reaction of 2a , b with hydrazine hydrate afforded the N-amino-2-iminopyridines 5a , b . These were converted into the triazolo[1,5-a]pyridines 8a–d on treatment with benzoyl chloride and with dimethylformamide dimethylacetal. On the other hand, the reaction of 2c with hydrazine hydrate afforded the pyrazolo[3,4-b]pyridine 7c . Treatment of 2a , c or 2e , g with cyanoethanoic hydrazide afforded the N-(cyanoacetamido)pyridines 9a , b . The dienes 2d , f , g afforded the pyridones 11a–c on treatment with acetic acid and hydrochloric acid mixture. Compounds 11b , c were also formed on treatment of 2b , c with acetic acid hydrochloric acid mixture. The reaction of 2d , g with ethanolic sodium ethoxide gave the ethoxypyridines 13a , b .     

8-（3-或4-氟苯甲酰基）-7-羟基-4-甲基香豆素的合成、晶体结构、抑菌活性、抗氧化活性及其与牛血清白蛋白的相互作用

设计并合成了两个新的氟代香豆素化合物8-（3-氟苯甲酰基）-7-羟基-4-甲基香豆素（3a）和8-（4-氟苯甲酰基）-7-羟基-4-甲基香豆素（3b）,其结构通过元素分析、IR和1HNMR进行了表征,通过X-射线单晶衍射测定了化合物3b的晶体结构,单晶结构分析表明,化合物3b的晶体属于单斜晶系.体外抑菌试验结果显示,目标化合物对大肠杆菌（E.coli）、枯草杆菌（B.subtilis）和金色葡萄球菌（S.aureus）有不同程度的抑制作用;体外抗氧化实验显示,目标化合物对超氧阴离子自由基（O2-·）和二苯代苦味肼基自由基（DPPH·）均有良好的清除能力;运用荧光光谱法研究了不同温度下目标化合物与牛血清白蛋白（BSA）的相互作用,结果表明,目标化合物对BSA的荧光猝灭均属于静态猝灭,相关热力学参数表明,化合物3a（H〈0,S〈0,G〈0）与BSA二者之间主要以氢键或范德华力相结合,化合物3b（H〉0,S〉0,G〈0）与BSA二者之间主要靠疏水作用力相结合;依据Fster＇s非辐射能量转移理论,求得BSA与化合物3a和化合物3b间的距离（r）分别为2.53和2.65nm,说明两个化合物与BSA之间可能发生了非辐射能量转移.     

Preparation of novel fluoroalkyl-end-capped 2-acrylamido-2-methylpropanesulfonic acid cooligomeric nanoparticles containing adamantane units possessing a lower critical solution temperature characteristic in organic media

Fluoroalkyl-end-capped 2-acrylamido-2-methylpropanesulfonic acid cooligomers containing adamantyl segments were prepared by reaction of fluoroalkanoyl peroxide with 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and 3-hydroxy-1-adamantyl acrylate (Ad-HAc). These obtained fluorinated AMPS-Ad-HAc cooligomers were found to form nanometer-size-controlled fine particles not only in water but also in a large variety of traditionally organic solvents. In addition, these fluorinated cooligomeric nanoparticles showed a good dispersibility in these solvents. Interestingly, the size of these fluorinated nanoparticles is extremely sensitive to solvent changes, and an increase of the particle size was observed in the solvents, in which the dielectric constant is higher or lower. More interestingly, these fluorinated AMPS-Ad-HAc cooligomeric nanoparticles exhibited a lower critical solution temperature around 52 degrees C in an organic medium (tert-butyl alcohol).