过氧化物酶新型荧光底物3,4-二氢-2(1H)-喹喔啉酮的反应机理及性能的研究

合成了过氧化物酶新型荧光底物3,4-二氢-2(1H)-喹喔啉酮(DHQXL). 在过氧化物酶催化下,该化合物可被H₂O₂氧化生成强荧光物质2(1H)－喹喔啉酮(QXL). 用高压液相色谱法分离得荧光产物纯品,经核磁共振谱和质谱证实其结构,确证了提出的酶催化反应机理. 对该化合物作为荧光底物的性能研究表明,它是一个很有应用前景的过氧化物酶的新型荧光底物.     

可见光促进环烷醇氧化开环的喹喔啉酮烷基化反应

报道了可见光促进张力环烷醇氧化开环后实现喹喔啉酮的C(3)-酮烷基化反应. 室温下, 该反应以张力环醇为潜在的烷基化试剂, 过硫酸钾为氧化剂, 在甲醇与水的混合溶液中, 借助可见光照射实现. 通过该反应, 一系列带有羰基官能团的不同链长的烷基片段被成功地引入到各种取代的喹喔啉酮中, 为喹喔啉酮类化合物的修饰提供了更加绿色、环保和简洁的方法.     

2(1H)-喹喔啉系列衍生物的质谱研究

2(1H)-喹喔啉衍生物是一类重要的杂环化合物,可应用于药物,如用作受体及受体拮抗剂、杀菌剂等;还可用作植物生长调节剂、荧光探针等诸多领域.本文研究了一系列喹喔啉衍生物的电子轰击质谱,得到了一些裂解规律.     

喹喔啉类红光热活化延迟荧光材料研究进展

红光材料是显示三基色材料之一, 具有发射能量小、穿透能力强和背景荧光干扰小等优点, 被广泛应用于全彩显示、生物传感和光动力治疗等领域. 红光材料目前存在的问题主要有: (1)跃迁能级小, 其非辐射跃迁速率快, 导致量子效率普遍较低; (2)分子共轭较大, 存在较强的π-π堆积作用, 容易导致荧光淬灭; (3)分子设计需要更大的共轭, 在分子合成上较为困难. 热活化延迟荧光(thermally activated delayed fluorescence, TADF)材料作为具有全新的发光机制的材料能够通过反向系间窜越过程利用三重态激子发射荧光, 极大地提高了量子效率, 因此, 基于TADF机制的红光材料成为了近年来人们研究的热点. 由于结构的特点, 喹喔啉及其衍生物非常适合用来构建红光TADF分子. 从喹喔啉类TADF红光材料的分子结构视角出发, 对红光TADF材料的近年来的研究进行概述, 讨论分子结构对材料性能影响, 并且对其发展进行展望.     

环化及亚胺/酰胺部分氢化一锅法串联反应合成1,2,3,4⁃四氢喹喔啉

报道了一种利用价廉易得的邻苯二胺衍生物与α-酮酸酯经环化/钌催化的亚胺和酰胺氢化串联反应一锅法制备1,2,3,4-四氢喹喔啉的方法. 该方法使用原位生成的Ru(acac)₃/Triphos配合物和HBF₄共催化剂组成的催化体系, 高效制备了一系列2-取代的1,2,3,4-四氢喹喔啉, 官能团耐受性良好. 在较低的氢气压力和不使用助催化剂的条件下, 反应可停留在只生成3,4-二氢喹喔啉酮产物阶段. 反应机理研究表明, 钌催化剂仅用于还原亚胺和酰胺部分, 而布朗斯台德酸助催化剂的选择对于酰胺部分去氧氢化至关重要. 研究表明, 布朗斯台德酸助催化剂通过活化酰胺部分参与催化过程.     

可见光诱导下喹喔啉酮与吡咯衍生物的氧化偶联（英文）

发展了一种区域选择性的喹喔啉酮3-位氧化偶联富电子吡咯衍生物的方法.以Mes-Acr-Me⁺ClO₄^-(3 mol%)为光敏剂,空气氧为氧化剂,高收率得到喹喔酮与吡咯衍生物的氧化偶联产物.该方法底物的官能团适用范围广,反应高效绿色,可快速构建基于喹喔啉酮-吡咯衍生物的药物分子库.相同测试条件下的Stern-Volmer荧光淬灭实验表明缺电子芳烃1-甲基喹喔啉酮对光敏剂的淬灭速率常数K_q=1.2×10⁹ L·mol^-1·s^-1,而富电子芳烃1-甲基吡咯/1-甲基吲哚的淬灭常数约为1.06～1.07×10¹⁰ L·mol^-1·s^-1,后者的荧光淬灭速率几乎是前者的10倍.     

基于苯乙烯腈结构的可逆力致变色化合物的合成及性能

合成了一种棒形的化合物4,4'-二(α-腈基-4-苯丙氧基苯乙烯)联苯(Ben-DCSB), 利用核磁共振(NMR)、质谱(EI-MS)、傅里叶变换红外光谱(FT-IR)和元素分析等对其进行了结构表征. 对Ben-DCSB重结晶粉末进行研磨后, 其发光颜色从蓝绿色变成黄绿色, 荧光量子效率(Φ_F)从初始的52.7%变为38.7%, 表明该化合物具有力致变色性质. 扫描电子显微镜(SEM)、X-射线衍射(XRD)和荧光寿命等测试结果显示, 这种现象是由于在外界环境刺激下改变了Ben-DCSB在聚集态下的分子堆积结构所造成的. 研磨后的样品暴露在溶剂蒸气(乙醇、二氯甲烷、四氢呋喃或丙酮)或100 ℃温度下放置2 min又能转换回初始状态的蓝绿色荧光, 表明化合物研磨后的样品具有气致和热致变色性能, 且展现出可逆变色性能. 对该化合物进行多次“力-溶剂蒸气刺激”和“力-热刺激”循环实验, 结果显示其具有很好的荧光可逆转换性能. 热分析结果显示化合物Ben-DCSB在194 ℃和212 ℃间存在向列相(纹影织构)的液晶态; 其热分解温度为362 ℃, 表明该化合物具有较好的热稳定性.     

硅烷桥联四苯乙烯-寡聚噻吩衍生物的结构与光谱性质（英文）

设计合成了一系列硅烷桥联四苯乙烯(TPE)-寡聚噻吩衍生物.硅烷取代基为甲基和苯基,寡聚噻吩单元中噻吩数量为1～3,通过空间位阻效应和电子效应调控分子的固态发光性质.具有苯基取代基的硅烷和二噻吩分子表现出高达64.5%的固态发光.含1或2个噻吩单元的分子的固态和液态荧光性质类似四苯乙烯,而含3个噻吩的分子的发光则主要来自于三噻吩,其在液态和聚集态分别有1.4%和14%的发光效率.苯基硅烷桥联三噻吩-四苯乙烯分子的聚集体具有检测硝基爆炸物的能力和防伪应用潜力.     

具有聚集诱导发光性质二芳基喹喔啉衍生物及其在检测Hg2+的应用

荧光传感器由于具有高灵敏度和高选择性,在检测化学方面具有很高的应用。我们合成了具有活性荧光团的聚集诱导发光物质：二芳基喹喔啉衍生物（1-4）类物质,并对其进行表征。化合物3同时具有AIE特征的二芳基喹喔啉、和Hg2+具有特殊反应1,3-二硫杂环戊二烯-2-硫酮的基团,我们将这两个特征基团耦合在同一个化合物之中,从而构建了一类新的“开-启”型汞离子荧光传感器。     

一种蓝光单体的合成及其荧光性能研究

吡唑啉衍生物在生物医药[1,2]应用的领域非常广泛.吡唑啉还是一种优质的发光材料[3],其发射波长位于450nm左右,具有很高的荧光量子效率,且发光波长窄,色纯度好,是一种纯正的蓝光.当吡唑啉环3位引入给电子基时,化合物则具有很高的荧光量子产率,可制得具有高热稳定性的空穴传输蓝光发光材料[4-6]和荧光探针[7].它还可以将吸收的不可见的紫外光转变为蓝色的可见光反射出来,从而增加了光线的反射率,使被其处理过的物体白度和光泽提高,所以吡唑啉又被做为荧光增白剂和荧光染料[8,9]进行广泛地应用.     

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%.     

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.     

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.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.