共查询到20条相似文献,搜索用时 31 毫秒
1.
R. Sateesh Chandra KumarG. Venkateswar Reddy K. Suresh BabuJ. Madhusudana Rao 《Tetrahedron letters》2011,52(34):4382-4384
A highly stereoselective total synthesis of (+)-(8R,8aR)-perhydro-8-indolizidinol is described. Key steps involved in this synthesis are diastereoselective zinc allylation, azido-olefin cyclization and reductive amination followed by cyclization which effectively constructed the indolizidine ring. This contributes a unique approach to the synthesis of indolizidine alkaloids that offers the advantages of brevity and relatively high overall yields. 相似文献
2.
5-[2-(8-羟基喹啉-2-基)乙烯基]-2-甲基-8-羟基喹啉的合成、抗氧化活性及促进鼠骨髓间质干细胞增殖的研究 总被引:1,自引:0,他引:1
设计合成了5-[2-(8-羟基喹啉-2-基)乙烯基]-2-甲基-8-羟基喹啉(5), 用IR, UV, 1H NMR, MS和元素分析确认其结构. 利用DPPH•法和噻唑蓝比色法(MTT法)分别测定了目标产物的抗氧化活性及调控鼠骨髓间质干细胞(MSCs)增殖的作用. 结果表明, 目标产物有较强的抗氧化活性, 在低浓度时对鼠骨髓间质干细胞有促进作用. 相似文献
3.
Ghasem Marandi Lotfali Saghatforoush Rafael Mendoza-Meroño Santiago García-Granda 《Tetrahedron letters》2014
The synthesis of a number of 3-(alkylamino)-2-arylimidazo[1,2-a]pyridine-8-carboxylic acids via a facile route involving the reaction between 2-amino-3-pyridinecarboxylic acid, benzaldehyde derivatives, and isonitriles is reported. The structures of the synthesized compounds are proved by X-ray crystallography. 相似文献
4.
(E)-N-芳基-3-[2-(8-羟基喹啉基)-乙烯基]咔唑的合成、抗氧化活性及促进鼠骨髓间质干细胞增殖的研究 总被引:4,自引:0,他引:4
设计合成了3-[2-(8-羟基喹啉基)-乙烯基]-N-对甲苯基咔唑(8)和3-[2-(8-羟基喹啉基)-乙烯基]-N-对甲氧苯基咔唑(9)两个新的化合物, 用IR, MS, 1H NMR和元素分析确认其结构. 并利用DPPH8226;方法, 超氧阴离子自由基( )法, 羟基自由基HO8226;法和噻唑蓝比色法(MTT法)分别测定了目标产物的抗氧化活性和调控鼠骨髓间质干细胞(MSCs)的作用. 结果表明, 这两种化合物对DPPH8226;自由基、超氧阴离子自由基和羟基自由基具有较强的抗氧化活性, 化合物9在低浓度时对鼠骨髓间质干细胞增殖有很好的促进作用. 相似文献
5.
Rémi D. Bergougnant 《Tetrahedron》2007,63(44):10751-10757
The macrocycle 4-tert-butylcalix[8]arene (L) was reacted with alkali metal carbonates (Li2CO3, Na2CO3, K2CO3, Rb2CO3, and Cs2CO3) at the interface of a biphasic THF/water system. Needle-like crystals with a general formula [Ax(4-tert-butylcalix[8]arene-xH)(THF)y(H2O)z] (with A=Li, Na, K, Rb, Cs, x=1, 2, y=4, 5, 8, and z=6, 7) were thereby obtained. The solid state structures were investigated by X-ray diffraction of single crystals and by TGA measurements. They do not appear to be maintained in solution. 相似文献
6.
Photoreactions of 2-halotropones with the excited 9,10-dicyanoanthracene gave a meta-adduct and substitution products occurred at the C-2 position of troponoids. The mechanism of the meta-adduct was proved by the product analysis of the reaction of 3,7-dideuterio-2-bromo-5-isopropyltropone and 9,10-dicyanoanthracene. In the photoreaction of 2-chloro-5-isopropyltropone and 9,10-dicyanoanthracene in a mixed solvent of benzene and methanol, a benzaldehyde with a dibenzo-2-oxabicyclo[3.2.2]nonane system was obtained to support occurrence of an [8+4] cycloaddition reaction between them. 相似文献
7.
Irina O. Zhuravel Oleg V. Zaremba Oleksandr S. Detistov Svitlana S. Kovalenko Valentin P. Chernykh 《合成通讯》2013,43(21):3778-3784
New 5-hydroxymethyl-8-methyl-3-(3-aryl-[1,2,4]oxadiazol-5-yl)-2H-pyrano-[2,3-c]pyridin-2-ones and their esters were synthesized. The structure of obtained compounds was determined through a complete 1H NMR analysis. 相似文献
8.
An alternate approach to 2-(substituted phenyl)-3,3a-dihydro-8H-pyrazolo[5,l-a] isoindol-8-ones via chalcone-based N-formyl-pyrazolines is described. N-Formyl-pyrazolines were prepared in excellent yield (81–96%) by the reaction of chalcones with hydrazine hydrate in the presence of formic acid, which undergoes intramolecular Friedel–Crafts acylation in the presence of trifluoroacetic acid (TFA) as a catalyst to afford functionalized 2-(substituted phenyl)-3,3a-dihydro-8H-pyrazolo[5,1-a]isoindol-8-ones in good to excellent yield (74–94%) at reflux in acetonitrile. Our synthetic route avoids expensive reagents and significantly improves yields. 相似文献
9.
LUO Ya-nan XU Xian-zhu ZHANG Xiao YU Xiao-yang QU Xiao-shu YANG Yan-yan SHEN Qi-hui 《高等学校化学研究》2013,29(6):1045-1049
One new coordination polymer based on 4-[(8-hydroxy-5-quinolinyl)azo]-benzoic acid(H2L), { [CdL(H20)]·H2O}n(1) was solvothermally synthesized and structurally characterized by single-crystal X-ray diffrac- tion, infrared spectrometry, elemental analysis, powder X-ray diffraction(PXRD) and thermogravimetric analysis (TGA). In compound 1, L2- ligands link Cd(II) to form a sinusoidal ruffling layer, in which the carboxylic groups connect Cd(II) into an infinite Cd--O chain. And the layers are further stabilized by hydrogen bonding and π-π in- teractions, forming a three-dimensional(3D) supramolecular network. In addition, the fluorescent property of compound 1 was also investigated. 相似文献
10.
合成了新的N-乙基咔唑衍生物: 3,6-二[2-(8-羟基喹啉基)乙烯基]咔唑(4)及其锌配合物(5); 化合物4经质谱、红外光谱、核磁共振氢谱、元素分析表征其结构, 并测定了它的荧光光谱. 结果显示: 化合物4的荧光发射为蓝绿色光(500 nm), 其发射光谱随着溶剂极性的增大荧光光谱向长波方向移动(即发生红移); 同时, 考察了化合物5的荧光性质, 其荧光发光峰值为600 nm, 与2-甲基-8-羟基喹啉锌相比, 发生了明显的红移. 相似文献
11.
12.
p-tert-Butylcalix[8]arene bonded capillaries for open-tubular capillary electrochromatography were prepared with γ-glycidoxypropyltrimethoxysilane as a bridge. The bonded capillary displayed low and steady electroosmotic flow (EOF) values over the pH range from 4 to 9. Detection limits for direct spectrophotometric detection at 277 nm for benzenediols (at a signal to noise ratio of 2) were 0.96 mg l−1 for the unbonded capillary and 1.48 mg l−1 for the bonded capillary, showing that the bonded layer did not show significant absorbance and hence decreased sensitivity. The bonded capillaries showed good separation selectivity for o-, m- and p-benzenediols, α- and β-naphthols, and α- and β-naphthylamines. This selectivity was attributed to significant interactions between the analytes and the bonded p-tert-butylcalix[8]arene, which contributed to the electrochromatographic separation mechanism. The bonded capillaries gave high stability and reproducibility. 相似文献
13.
《Analytical letters》2012,45(16):1343-1354
Abstract Electrochemical monitoring of 1, 4-dihydroxy-5, 8-bis-[2-(2-hydroxyethy1) aminoethy amino]-9, 10-anthracenedione was employed for the quantitation of this cancer chemotherapy drug following high performance liquid chromatography. Detection was performed by oxidation of the compound at a glassy carbon electrode at +0.80 V vs. SCE. A rapid and convenient sample treatment procedure was developed which is suitable for determination involving physiological samples. A detection limit of 2 ng injected was obtained for urine samples. 相似文献
14.
A short, versatile, and enantioselective synthesis of 1-deoxy-8-epi-castanospermine (5), 1-deoxy-8-hydroxymethyl castanospermine (6), and (6S,7S,8R,8aR)-8-amino-octahydroindolizine-6,7-diol (7) is achieved from a common template 12. The key step utilized is PET provoked amine radical cyclization of 11 to 12 in excellent diastereoselectivity. The exocyclic double bond at C-8 of the template is functionalized to obtain 5-7 as exclusive diastereomers. 1-Deoxy-8-epi-castanospermine exhibited inhibition of α- and β-galactosidase and β-glucosidase. Compounds 6 and 7 were found to be weak inhibitors of β-glucosidase. 相似文献
15.
A variety of functionalized 6-(trifluoromethyl)-6H-dibenzo[b,d]pyrans were easily synthesized in good yields under mild conditions by a domino reaction of 3-nitro-2-(trifluoromethyl)-2H-chromenes with 2-(1-phenylethylidene)- and 2-(1-phenylpropylidene)malononitriles. In the latter case, intermediate 7-amino-10-methyl-10-nitro-9-phenyl-6-(trifluoromethyl)-10,10a-dihydro-6H-benzo[c]chromene-8-carbonitriles were isolated as a result of a rare [1,5] sigmatropic shift of the nitro group. 相似文献
16.
An azobenzene bridge was introduced into the lower (or smaller) rim of p-tert-butylcalix[8]arene (1) and 1,5-calix[8]crown-3 (2) to form 1,4-singly bridged (3) and 1,5:3,7-doubly bridged (4) calix[8]arene derivatives, respectively. Trans and cis isomers of conformationally rigid 4 were isolated. The quantum yields of the trans-cis photoisomerisation reactions have been measured. 相似文献
17.
Pierre Raboisson Dominique SchultzClaire Lugnier Romain MathieuJean-Jacques Bourguignon 《Tetrahedron letters》2003,44(4):703-705
An expedient synthesis of 8-acylamidopyrazolo[1,5-a]-1,3,5-triazines was developed by treating 8-amino-4-[N-(4-aminophenyl)-N-(methyl)amino]pyrazolo[1,5-a]-1,3,5-triazine with various acyl chlorides following by the displacement of the so-formed N-(methyl)-N-[4-(acylamido)phenyl]amino leaving group with various amines. Applications to high-throughput synthesis are suggested. 相似文献
18.
Reductive disilylation (Li+Me3SiCl−THF) of 1,3,5-cycloheptatriene led to 1,1′-bi[(S∗,S∗)-6-(trimethylsilyl)cyclohepta-2,4-dien-1-yl] (2). In the presence of TiCl4 in dichloromethane, 2 gave rise to a spherical molecule 5 resulting from an intramolecular formal [4+4] supra-supra cycloaddition. 相似文献
19.
Tushar S. Basu Baul Archana Mizar Eleonora Rivarola Michal Hol?apek Ulli Englert 《Journal of organometallic chemistry》2006,691(16):3416-3425
A series of cis-bis{5-[(E)-2-(aryl)-1-diazenyl]quinolinolato}diphenyltin(IV) complexes have been synthesized and characterized by 1H, 13C, 119Sn NMR, ESI-MS, IR and 119mSn Mössbauer spectroscopic techniques in combination with elemental analysis. The structures of a ligand L6H (i.e., 5-[(E)-2-(4-ethoxyphenyl)-1-diazenyl]quinolin-8-ol) and three diphenyltin(IV) complexes, viz., Ph2Sn(L1)2 · (CH3)2CO (1), Ph2Sn(L4)2 (4) and Ph2Sn(L5)2 (5) (L = 5-[(E)-2-(aryl)-1-diazenyl]quinolin-8-ol: aryl = phenyl - (L1H); 4′-methylphenyl - (L4H) and 4′-bromophenyl - (L5H)) were determined by single crystal X-ray diffraction. In general, the complexes were found to adopt a distorted cis-octahedral arrangement around the tin atom. These complexes retain their solid-state structure in non-coordinating solvent as evidenced by 119Sn NMR spectroscopic results. The in vitro cytotoxicity of 1 is reported and compared with Ph2Sn(Ox)2 (Ox = deprotonated quinolin-8-ol) against seven well characterized human tumor cell lines. 相似文献
20.
Yoko Kameda 《Tetrahedron》2006,62(41):9751-9757
(4R,8R)-4,8-Dimethyldecanal, a common aggregation pheromone of Tribolium flour beetles, has been synthesized from (R)-2,3-O-isopropylideneglyceraldehyde in 11 steps and 7% overall yield. The key step in the synthesis is the highly diastereoselective chelation-controlled radical reaction of ethyl (4S,5R)-4-benzyloxy-5,6-(isopropylidenedioxy)-2-methylenehexanoate with ethyl (R)-5-iodo-3-methylpentanoate performed in the presence of 7 equiv of MgBr2·OEt2. 相似文献