衍生于苯并-12-冠-4的双光子荧光Fe3+探针

合成了双光子荧光探针2,5-二氰基-1,4-二[2′-(4′-苯并-12-冠-4)乙烯基]苯(1),并进行了红外、质谱及元素分析。探针1在单、双光子荧光发射中对金属离子显示了相似的选择性,双光子过程中的选择性略优于单光子过程,并对Fe3+显示出高度选择性识别。探针1对Fe3+的单、双光子荧光强度随Fe3+浓度的升高而急剧降低;单、双光子荧光滴定过程中探针对Fe3+的络合常数分别是:5.70±0.03(logK11)与4.74±0.05(logK12)、5.76±0.04(logK11)与4.81±0.07(logK12)。探针1的双光子吸收截面(δTPA)随溶剂极性增加而减小,在甲苯与乙腈中的δTPA分别是2198,1125GM,探针与Fe3+络合后其双光子吸收截面显著减小。研究结果表明,化合物1可以作为Fe3+探针应用到单光子激发荧光与双光子激发荧光检测;可以用开发单光子荧光探针的策略来设计应用于生物成像的双光子荧光探针。     

用于检测铁(Ⅲ)离子的新型共轭聚合物荧光探针

以1,10-邻菲咯啉为原料合成了1,10-菲咯啉-5,6-二酮,并进一步与对苯二胺通过席夫碱反应合成共轭聚合物荧光探针。通过核磁共振、红外光谱、黏度等对聚合物进行表征,通过紫外吸收与荧光发射光谱研究了此聚合物对金属离子的识别性和敏感性。对1,10-邻菲咯啉与聚合物探针配位Fe3+前后的吸收光谱、荧光光谱以及红外光谱进行对比研究。实验结果表明:在聚合物溶液中,加入Fe3+后溶液由无色变为浅红棕色,可实现肉眼识别检测Fe3+,而紫外吸收和发射光谱的变化表明此聚合物荧光探针对Fe3+具有较好的选择性和灵敏性;其对加入的Fe3+能瞬间响应(1 s),完全响应时间为30 min,对Fe3+的线性检测范围为0~12.5μmol/L,检出限为2.72μmol/L。Fe3+对探针的猝灭常数为1.52×104L/mol。通过分析聚合物荧光探针与Fe3+的作用机理,绘制出聚合物荧光探针与Fe3+作用后的结构示意图。     

新型吡啶-杯[4]芳烃荧光探针的合成及其对Fe3+的检测性能

合成了一种新型的高选择性检测Fe3+的上沿功能化吡啶-杯[4]芳烃荧光探针,其结构经1H NMR, 13C NMR和HR-MS表征。离子检测实验结果表明,该吡啶-杯[4]芳烃探针的最大吸收峰出现在295 nm处,并在371 nm处显示出一个强的荧光发射带。与其他金属离子相比,新型探针对Fe3+表现出高选择性和强抗干扰能力的荧光淬灭响应。通过荧光滴定法和Job曲线图研究了探针与Fe3+的结合性。结果表明,探针与Fe3+形成2:1的配合物,缔合常数为3.26×107 M-1,检出限为7.9×10-7 M。     

新型水溶性罗丹明类荧光探针的合成及其对游离3价金属离子的识别

以罗丹明B为原料,设计合成一种新型水溶性荧光探针(L),并对其进行表征和光学性能研究.结果表明,探针L能在纯水体系(TRIS,pH=7.4)中快速识别游离M3+(Cr3+、Al3+、Fe3+)金属离子,为荧光增强型探针,具有灵敏度高、抗干扰能力强的特点.探针L对Cr3+、Al3+、Fe3+的荧光检测限分别为1.57×1...     

罗丹明B并甘氨酸甲酯Turn-On型Fe3+荧光探针的合成及应用

铁离子是生物体内重要的元素之一.设计合成了基于罗丹明B-甘氨酸甲酯的Turn-On型Fe3+荧光探针,利用1 HNMR和LC-MS对其结构进行表征.研究结果表明:探针中加入Fe3+后展现出明显的荧光信号,当加入其他分析物(Fe2+、Hg2+、Zn2+、Ba2+、Al3+、Co2+、Cd2+、K+、Na+、Mn2+、Pd...     

脱氢枞酸基芳胺荧光探针探测金属离子的应用

通过脱氢枞酸基芳胺荧光探针a,b,c对不同金属离子(Ca2+、K+、Mg2+、Mn2+、Na+、Ni2+、Pb2+、Fe3+、Cu2+)的识别性、对其他金属离子的抗干扰性、以及金属离子对探针的荧光滴定试验,研究了它们作为金属离子荧光探针的应用。结果表明,a和b对Fe3+、c对Cu2+具有良好识别性,其识别性能受其他金属离子的干扰性不明显;Fe3+浓度分别在1.0×10-7~6.0×10-6mol·L-1和2.0×10-7~7.0×10-6mol·L-1范围内,a和b的荧光强度与Fe3+浓度有较好的线性关系,Cu2+浓度在6.0×10-6~3.0×10-5mol·L-1范围内,c的荧光强度与Cu2+浓度有较好的线性关系,可以定量检测中性水溶液中Fe3+和Cu2+含量。     

基于香豆素荧光团的高选择性Fe~(3+)荧光分子探针研究

设计合成了四种含有酰胺和酯基结构的香豆素荧光分子探针,其结构通过1H NMR、13C NMR和HRMS进行了表征,并对探针进行了常见金属离子识别性能的研究。发现该类探针对Fe3+产生荧光淬灭性响应,其中7-位带有二乙氨基的2-(7-二乙氨基香豆素-3-甲酰胺基)乙酸乙酯(C3)和3-(7-二乙氨基香豆素-3-甲酰胺基)乙酸丙酯(C4)对Fe3+的淬灭比例达到99.5%和99.6%,可作为识别Fe3+的探针。     

1,8-二（2-羟乙基）亚氨基蒽醌荧光探针用于Fe3+的高选择性测定

在蒽醌荧光团上修饰乙醇胺分子,合成了用于铁离子识别检测的新的荧光探针.实验结果表明,在乙醇∶水=4∶1,pH值为7.20的条件下,Fe3+的加入使体系荧光猝灭,荧光强度和Fe3+浓度在4.0×10-5—3.0×10-4 mol/L范围内呈线性关系,由此可以实现在乙醇/水体系中对Fe3+离子的高选择性检测.检测限为3.8×10-7 mol/L.     

基于罗丹明B新型Fe~(3+)荧光探针的合成及其性能研究

以罗丹明B与2,6-二氨基吡啶缩合反应得到新型罗丹明B衍生物R1,其结构经1H NMR,13C NMR,IR,HRMS-ESI,X-Ray单晶衍射及元素分析表征.研究发现化合物R1作为荧光探针能选择性比色地识别Fe3+,且受常见金属离子的干扰较小.探针R1的荧光强度与Fe3+浓度(4×10-6~1.6×10-5 mol/L)呈较好的线性关系,并在Hep G2活细胞中实现了Fe3+的成像.     

新型罗丹明B类荧光探针的合成及其对Fe3+识别研究

以罗丹明B和间氨基吡啶缩合反应得到新型罗丹明B衍生物L1,并用1H NMR,IR,HRMS-ESI及X射线对其结构进行了确证.通过荧光光谱法研究了目标物L1在水溶液中与金属离子的识别特性.结果表明目标物L1作为荧光探针可选择性的比色识别Fe3+,并且受常见离子的干扰较小.探针L1的荧光强度与Fe3+浓度(1×10-6~9×10-6 mol/L)呈较好的线性关系.     

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%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

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.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

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.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.