基于2,4,6-吡啶三羧酸配体桥连的铁(Ⅱ)/镍(Ⅱ)配位聚合物的水热合成及结构表征

在水热反应条件下FeCl₂·6H₂O、2,4,6-吡啶三羧酸(H₃pyta)和NaOH反应合成了1种一维链状铁配位聚合物[Fe₃(pyta)₂(H₂O)₈] (1);同样条件下Ni(OAc)₂·4H₂O、2,4,6-吡啶三羧酸(H₃pyta)、NaOH和4-氨基-3,5-二(4-吡啶基)-1,2,4-三氮唑(abpt)反应合成了1种二维网状镍配合物[Ni₃(pyta)₂(abpt)₂(H₂O)₃]·2H₂O (2)。通过元素分析和红外光谱对这2个配位聚合物进行了表征。单晶结构表明：配合物1的晶体属于单斜晶系,Cc空间群;配合物2的晶体属于单斜晶系,P2₁/c空间群。在配合物1中,pyta^3-配体采取μ₂-和μ₄-pyta^3- 2种桥连模式将Fe原子连成了沿c轴方向延伸的Fe-pyta链。而在配合物2中,pyta^3-配体仅采取μ₂-桥连模式将Ni原子连成线型三核[Ni₃(pyta)₂]单元,这些三核单元进一步通过abpt辅助配体桥连成二维 (4,4)层状结构。     

Use of the ring opening reactions of 1,3,5-triazines in organic synthesis (review)

Published data on the recyclization reactions of 1,3,5-triazines are reviewed. The classification is based on the fragments of the 1,3,5-triazine molecules used in the construction of new heterocycles. Dedicated to the birthday of A. F. Pozharskii, who has made a great contribution to our establishment as scientists. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 167–190, February, 2009.     

Efficient synthesis of phosphonodepsipeptides derived from norleucine

In the present work, we describe in detail an efficient solution synthesis of norleucine-derived phosphonopeptides mimicking the peptide sequences Nle-Gly(Ala) and Nle-Gly(Ala)-Val. The most efficient strategy involved use of the benzyl group. The synthesis was achieved through BOP-catalysed coupling of the monobenzyl ester of the N-Cbz-protected phosphonate derivative of norleucine with the hydroxyl moieties of derivatised l-lactic or glycolic acid. Subsequently, complete deprotection of the products was achieved in good yields by one-step Pd-catalysed hydrogenolysis. We also prepared the Fmoc-Nle-Ψ[PO(OH)O]-CH₂-COOH synthon and demonstrated that this precursor is a suitable building block for the solid-phase synthesis of cysteine-containing phosphonopeptides.     

Isoliquiritigenin (4,2′,4′-trihydroxychalcone): A new matrix-assisted laser desorption/ionization matrix with outstanding properties for the analysis of neutral oligosaccharides

A novel matrix of isoliquiritigenin (ISL), a flavonoid with a chalcone structure (4,2′,4′-trihydroxychalcone), was demonstrated to be advantageous in the analysis of neutral oligosaccharides by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). With ISL as a matrix, adequate signal for an analyte can be obtained in much lower matrix concentrations and laser intensity compared to commonly used MALDI matrices. Four different sample preparation methods were tested, and the dried droplet method exhibited the best performance on MALDI-TOF-MS analysis of oligosaccharides with ISL as a matrix. For the analysis of carbohydrates, compared with popular matrices such as 2,5-dihydroxybenzoic acid (DHB) and 2,4,6-trihydroxyacetophenone (THAP), ISL exhibited outstanding matrix properties as follows: (1) higher homogeneity of crystallization thus allowing automatic data acquisition, (2) better spectral quality in terms of resolution and signal to noise ratio (S N⁻¹), (3) better salt tolerance, (4) higher sensitivity, and (5) enough fragmentation yield to use LIFT-TOF/TOF MS to get richer structural information. In addition, reliable quantitative analysis of oligosaccharides with a good linearity over two concentration orders (1–100 pmol μL⁻¹) and good reproducibility of the signal intensity (RSD less than 15%) were achieved using this matrix. These results give a new outlook on high-speed analysis of neutral carbohydrates by MALDI-TOF MS.     

利用手性相转移催化剂不对称合成旋光性2,4,6-三甲基苯丙氨酸

以甘氨酸(Ⅰ)为原料,在羧基保护下合成底物苯亚甲氨基乙酸乙酯(Ⅲ),然后经手性催化剂(-)-N-苄基氯化辛可尼定(BCDC)和(+)-N-苄基氯化辛可宁(BCNC)的催化,酸水解得到旋光性的2,4,6-三甲基苯丙氨酸(V-2,V-3),总收率分别为28％和31％,比旋光度分别为[α]20D=+16°和[α]20D=-9...     

手性多齿配体的合成及其在二乙基锌对苯甲醛不对称加成反应中的应用

以(1R,2R)-1,2-二苯基乙二醇和2,4,6-三氯-1,3,5-三嗪为原料,经保护、取代、去保护等反应合成了3个新的手性多齿配体,并将其应用于二乙基锌对苯甲醛不对称加成反应中。结果表明,2,4-二(4-吗啉基)-6-((1R,2R)-1,2-二苯基-2-羟基乙氧基)-1,3,5-三嗪在此反应中的效果最好,所得产物ee值为32%。     

（TAGH）2（TNR）的合成、晶体结构及热分析

合成了三氨基胍三硝基间苯二酚盐(TAGH)2(TNR)(TAG)三氨基胍;TNR:2,4,6-三硝基间苯二酚),并对其进行了元素分析及红外光谱表征.利用X射线单晶衍射分析测定了其晶体结构.该晶体属于单斜晶系,空间群为C2/c,晶体学数据为,a=2.2892(6)nm,b=1.2802(3)nm,c=1.3661(4)nm,β=111.174(5)°,V=3.7333(16)nm3,Z=8.该化合物是由二个C(N2H3)3+与一个(C6HN3O8)2相结合而成的离子型化合物.用差示扫描量热法、热重法和微商热重法研究了该化合物的热分解过程,研究结果表明,在10 K·min-1的升温速率下,该化合物只有一个剧烈的放热分解过程,该过程发生在450.1-477.7K之间,且分解产物主要是气体产物.     

Regioselective synthesis of novel 4-aryl-2-ethylthio-7-methyl pyrazolo[1,5-a]-[1,3,5]-triazines

Pyrazolo[1,5-a]-[1,3,5]-triazines 6a-d were obtained by an efficient one-step reaction from S,S-diethyl aroyliminodithiocarbonates 4a-d and 5-amino-3-methylpyrazole 5 or by an alternative two-step reaction from 5 and aroyl isothiocyanates 8a-d to give initially the thiourea derivatives 9a-d, which after S-ethylation and cyclization afforded compounds 6a-d. The intermediate 7a isolated from reaction between 4a and 5 permitted us to establish the orientation.     

Synthesis,characterization, and DNA binding of two copper(II) complexes as DNA fluorescent probes

[Cu(DAPT)₂Cl]Cl·H₂O and [Cu(DBM)(DAPT)Cl] [DAPT = 2,4-diamine-6-(pyrazin-2-yl)-1,3,5-triazine] were synthesized and characterized by IR and UV spectroscopy, elemental analysis, TG–DTA, molar conductivity, and LC–MS. The interaction with calf thymus DNA (ct-DNA) of the two complexes has been studied using UV spectra, fluorescent spectra, cyclic voltammetry, and viscosity measurements. The complexes interact with ct-DNA through classical intercalation. Fluorescence intensity changes of 1 and 2 in the absence and presence of ct-DNA have been investigated for quantitative determination of ct-DNA with the limit of detection of 3.8 and 7.7 ng mL^?1, respectively. From the result, the two complexes are potentially sensitive DNA fluorescent probes.