含香豆素骨架的缩氨基硫脲化合物的合成和抑菌活性研究

由含不同取代基的水杨醛与乙酰乙酸乙酯在六氢吡啶存在下,得到一系列乙酰基香豆素中间体,然后进一步与氨基硫脲发生缩合反应,得到含有香豆素骨架的缩氨基硫脲化合物,目标化合物的结构均由IR、1H NMR 13C NMR和HRMS确证.它们对大肠杆菌和枯草杆菌具有优良的抑制效果,其中以二氯代的标题化合物的效果最佳.     

微波辐射下N-[4-(香豆素-3-基)噻唑-2-基]芳醛腙类化合物的合成及生物活性研究

由含不同取代基的芳香醛与氨基硫脲缩合成缩氨基硫脲,继而与α-溴代乙酰基香豆素经微波辐射合成了14种新的N-[4-(香豆素-3-基)噻唑-2-基]芳醛腙类化合物,产率达到69%～97%.其结构通过1H NMR,IR和HRMS进行了确证.试验表明部分目标化合物具有一定的抑菌生物活性.     

N-(4-苯基-噻唑-2-基)芳醛腙类化合物的合成

以芳醛与氨基硫脲进行缩合得到缩氨基硫脲, 分别与ω-溴苯乙酮进行成环反应得到了一系列含噻唑环和芳基的腙类化合物, 并通过用¹H NMR、质谱、红外光谱等对化合物进行了结构表征.     

2-(1,11-十一亚甲基)-5-取代亚氨基-△~3-1,3,4-噻二唑啉的合成及杀菌活性

通过环十二酮与 N -取代氨基硫脲的缩合反应 ,合成了一系列 N -取代环十二酮缩氨基硫脲 ,经Mn O2 氧化关环 ,得到 1 5种未见文献报道的标题化合物 ,其结构经 IR,1 3C NMR,元素分析的确证 .初步实验表明 ,部分化合物具有一定的杀菌活性     

8-羟基喹啉-7-醛缩氨基硫脲衍生物的微波合成及抗肿瘤活性研究

以8-羟基喹啉-7-醛和一系列芳基及烷基取代氨基硫脲为原料,合成了15种8-羟基喹啉缩氨基硫脲类化合物。缩合反应在绿色溶剂水中进行,微波辐射下15-30 min内反应完全,操作简单,收率高。化合物结构经1H NMR、IR和高分辨质谱确证。部分化合物经抗肿瘤活性初步测试结果表明,多数化合物对细胞周期分裂蛋白25B(CDC25B)抑制率达到90%以上,具有潜在的抗肿瘤活性。     

2-(1,11-十一亚甲基)-5-取代亚氨基-Δ3-1,3,4-噻二唑啉的合成及杀菌活性

通过环十二酮与N-取代氨基硫脲的缩合反应,合成了一系列N-取代环十二酮缩氨基硫脲,经MnO2氧化关环,得到15种未见文献报道的标题化合物,其结构经IR,13C NMR,元素分析的确证. 初步实验表明,部分化合物具有一定的杀菌活性.     

区域选择性合成2-取代磺酰基亚肼基-3-全乙酰糖基-2,3-二氢噻唑及其表征、生物活性研究

以取代磺酰肼和糖基异硫氰酸酯反应,生成8种1-取代磺酰基-4-全乙酰糖基氨基硫脲,然后在ClCH2CHO/CH3COONa/DMF条件下关环,区域选择性地合成了一系列新型2-取代磺酰基亚肼基-3-全乙酰糖基-2,3-二氢噻唑.化合物3e的1H-13CHMBC谱图表明1-取代磺酰基-4-全乙酰糖基氨基硫脲与氯乙醛的缩合反应关环位置为氨基硫脲的N-4,而非N-2.所有新化合物的结构均经过1HNMR,13CNMR和元素分析确证,生物活性初步测定结果表明该类二氢噻唑化合物具有一定的除草活性.     

1-(2-苯并噻唑基)-5-(2-苯基-1,2,3-三唑基)-3-芳基-2-吡唑啉衍生物的合成及其荧光性能

以2-苯基-1,2,3-三唑基-4-甲醛为原料,与苯乙酮或取代苯乙酮发生羟醛缩合生成相应的查尔酮；再与2-肼基苯并噻唑反应,合成了5个含1,2,3-三唑基、苯并噻唑基的新型吡唑啉衍生物，其结构经¹H NMR、 IR和元素分析表征。荧光性能研究结果表明：该类化合物具有良好的荧光性,其最大发射波长在427～444 nm,荧光强度大小与衍生物中不同的取代基有关     

2-羟基-1-萘甲醛缩-N(4)-取代氨基硫脲的合成与抑菌活性

苯胺或取代苯胺、二硫化碳与水合肼在氢氧化钾催化下经加成与取代反应合成了10种N(4)-取代氨基硫脲,随后在浓盐酸催化下分别与2-羟基-1-萘甲醛加成合成了10种未见报道的2-羟基-1-萘甲醛缩-N(4)-取代氨基硫脲.通过IR、1 H NMR与13 C NMR对标题化合物进行了结构表征;采用离体法初步测试了标题化合物对6种常见农作物真菌病源菌的抑菌活性,并推测其可能的构效关系.结果表明,标题化合物对水稻纹枯病菌、小麦赤霉病菌、番茄早疫病菌、黄瓜枯萎病菌、马铃薯晚疫病菌及辣椒疫霉病菌均表现出一定的抑菌活性,其抑菌活性大小与标题化合物N(4)-取代基中苯环所连取代基的类型与位置有关.     

2-取代氨基-5-去氢枞基-1,3,4-噁二唑衍生物的合成及除草活性

以去氢枞酸为原料,经酰化后与水合肼反应合成去氢枞酰肼3,再与芳基异硫氰酸酯反应,得到中间体1-去氢枞酰基-4-取代基氨基硫脲4,4在Hg(OAc)2/EtOH条件下关环,合成得到一系列新型2-取代氨基-5-去氢枞基-1,3,4-噁二唑化合物5.采用IR,MS,1HNMR,13C NMR和元素分析等方法对中间体4和目标产物5进行了分析和表征.初步的除草活性测试表明,化合物4和5对油菜的胚根生长以及对稗草的幼苗生长有一定的抑制作用,其中化合物4d在浓度为100mg/L时对油菜胚根生长的抑制率达88.2％.     

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%).