脂肪族方酰胺多齿配体的合成

曾合成并研究了以1,3-双苯氨基方酸内翁盐为骨架,在苯环的2-位对称引入多甘醇醚链的双臂型方酰胺多齿配体,其中某些化合物既能作为配体对UO~2^2^+及ZγO^2^+等刚性离子配位,又能与配体NH~3发生作用,以它作为中性载体的氨选择性电极可望用于NH~3的测定。在脂肪胺的方酸内翁盐型多齿配体中,因无芳环的共轭,四碳环及其上氧之电荷状态将有所不同,这必将影响整个分子的性质。本文对这类化合物的合成进行探索,找到了行之有效的合成方法,并由此制得了九个方酰胺配体5(a～i),其中5i可作为聚酰胺等的稳定剂,其余均未见文献报道。     

1,3-双(N-取代苯氨基)方酸内鎓盐的合成

在方酸内鎓盐中,四碳环的电荷分离使其氧原子带部分负电荷,成为潜在的良好配位基。 据此,作者于前文中合成了以双苯氨基方酸内鎓盐为骨架、苯环的2—位对称引入多甘醇醚氧 链的多齿配体,并以它们为萃取剂或电活性物质成功地实现了水相中UO_2~(2 )的萃取及碱水中NH_3 的测定。如果配基链由苯环的2—位移至N上,整个配体分子的几何及电子结构将发生改变, 四碳环上的氧与侧链的匹配情况也将不同。此外,苯环上的取代基将可能通过共轭体系直接影响 四碳环上氧的电荷状态及配位能力。因此,本文合成并研究了一类新的1,3—双(N—取代苯氨基) 方酸内鎓盐型多齿配体2(a～h)(见下式)。     

磺酰胺型多齿配体的合成

有机金属配合物涉及了许多重要的生命过程,配体和配合物的合成及性质研究都越来越受到人们的重视。磺酰胺类化合物,磺酰胺中氨基氢的酸性可与酚类化合物相比拟,对金属离子有较强的配位能力,并且比酚试剂不易氧化,还可改变磺酰胺的空间体积和亲脂性。本文报道一类新的磺酰胺型多齿配体的合成,并证明它们能与金属离子形成配合物。     

不对称芳基取代的方酰胺和异方酰胺的合成

Ｎ－芳基氮氧方酸的活性羟基能够被芳伯胺取代。利用这一特性，可在方酸四碳环上引入另一不同的芳胺基，即可获得不对称芳基取代的方酰胺或异方酰胺。以乙醇等为介质，芳伯胺与７种Ｎ－芳基氮方酸反应，制得２５个不对称的方酰胺和２４个不对称的异方酰胺。该合成方法优点突出，反应简便有效，通用性强。     

新型酰胺金属配合物的热力学稳定性研究

酰胺在自然界中广泛存在,生物体内很多金属酶中的酰胺都参与了金属配位,文献表明,配位的金属离子可以促进酰胺的去质子化,去质子后的酰胺氮原子是一种良好的电子授体,当前对酰胺配体的研究已有报道,为模拟抗癌药物博莱霉素,Rowland等合成了一个新型五齿酰胺配体：N,N-双(2-吡啶甲基)胺-N-乙基-2-吡啶-2-甲酰胺(L),并对其三价铁配合物的单晶结构进行了表征,实验证明此配体在配合物中的配位环境和化学性质与博莱霉素非常相似。     

N—芳基氮氧方酸与HMPA的反应

Ｎ－芳基氮氧方酸与ＨＭＰＡ的反应＊陈益钊李聚才（四川大学化学系成都６１００６４）黄锋（中国人民解放军防化研究院北京１０２２０５）陈凌勇（泸州医学院泸州６４６０００）关键词Ｎ－芳基氮氧方酸六甲基磷酰胺酰胺的酸解环丁烯二酮方酸化学中图分类号Ｏ６２４．４２...     

1,3-双(N-取代苯氨基)方酸内翁盐的合成

本利用方酸和苯胺合成了一类新的1,3-双(N-取代苯氨基)方酸内翁盐型多齿配体. 其中一些方酸内翁盐具有较强的与Cu^2^+, Co^2^+, Zn^2^+等配位的能力.     

吡啶酰胺类配体及其配合物研究进展

本文按吡啶酰胺类化合物末端吡啶氮原子个数的不同,将其分为单吡啶酰胺配体、双吡啶酰胺配体和多吡啶酰胺配体三类,总结了近些年来在这类配体及其金属配合物的合成方法和结构特征方面的研究成果。结合文献和我们的工作,比较详细的描述了研究相对较少的3-(或4-)吡啶酰胺配体及其配合物的研究进展。     

多齿配体吡啶-2,6-双酰胺对Cr(Ⅲ)和Zn(Ⅱ)离子光谱识别性能研究

以吡啶-2,6-二甲酸为原料,通过酯化和酰胺化反应制备得到多齿配体吡啶-2,6-二[N-(1’-甲基-2’-羟乙基)酰胺],并利用紫外-可见光谱分析方法研究了该配体对于重金属Cr~(3+)和Zn~(2+)离子识别性能。结果表明,该配体对于重金属Cr~(3+)和Zn~(2+)离子具有较高的选择性识别能力,并且不受其他金属离子的干扰。     

手性二氧大环多胺镍离子配合物的电化学研究

大环酰胺兼有寡肽和大环多胺的双重结构特征,是一类性质独特的大环配体,与大环多胺相比,该类配体对金属离子具有更好的选择性,并能稳定高价态的Cu3+和Ni3+.Kimura等[1]的研究发现十六元二氧大环五胺的镍配合物在室温就可以将苯氧化为苯酚.     

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%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.     

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%).