共查询到20条相似文献,搜索用时 247 毫秒
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建立了4个单手性和3个双手性(含有手性中心和面手性)的二茂铁衍生物在Chiralpak IC(纤维素-三(3,5-二氯苯基氨基甲酸酯))和Chiralpak IE3(直链淀粉-三(3,5-二氯苯基氨基甲酸酯))手性固定相上的高效液相色谱分离方法。4个单手性二茂铁衍生物中有3个可以在Chiralpak IE3固定相上实现基线分离,另外1个则在Chiralpak IC手性固定相上实现基线分离。3个双手性二茂铁衍生物可在Chiralpak IC手性固定相上实现基线分离。研究表明,这两种手性固定相对二茂铁衍生物具有较好的手性识别作用,并且具有互补作用。这一研究结果可为手性二茂铁化合物的分离提供借鉴和参考。 相似文献
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Acylation of some substituted 1,2,4-triazole-3-thiones in the presence of triethylamine gives N-substituted derivatives. S-Substituted derivatives, which are readily transacylated to the N-substituted derivatives on heating, are formed in the case of 4-phenyltriazolethiones in alkaline media. In the case of 4-allyltriazolethiones acylation in alkaline media gives only the N-substituted derivatives. Bromination of the acyl derivatives gives the disulfides. 相似文献
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Lauro Figueroa-Valverde Francisco Díaz-Cedillo Elodia García-Cervera Eduardo Pool-Gómez Marcela Rosas-Nexticapa María López-Ramos Maria Isabel Vera-Escobedo 《Journal of Saudi Chemical Society》2018,22(2):183-197
Several triazonine-carbaldehyde derivatives have been prepared using different protocols; however, some require special reagents and conditions. The aim of study involved the synthesis of two triazonine-carbaldehyde derivative using testosterone or OTBS-testosterone as chemical tool. Triazonine-carbaldehyde derivatives were prepared by a series of reactions that involve the following: (1) synthesis of two nitrobenzamide derivatives by reaction of testosterone or OTBS-testosterone with p-nitrobenzoyl azide using Copper(II) as catalyst; (2) reaction of the nitrobenzamides with ethylenediamine to form two triazonine derivatives using boric acid as catalyst; (3) preparation of hexynyl-triazonine derivatives by the reaction of two triazonines 6-chlorohex-1-yne in basic medium; (4) reaction of hexynyl-triazonine derivatives with benzaldehyde to form two triazoninol analogs; (5) preparation of triazoninynal derivatives through oxidation of triazoninol analogs with dimethyl sulfoxide; and (6) synthesis of triazonine-carbaldehyde derivatives by the reaction of triazoninynal derivatives with hexyne-1 using Copper(II) as catalyst. The chemical structure of compounds was determined by spectroscopic and spectrometric methods. In conclusion, in this work were prepared two triazoninone derivatives using several chemical techniques, which are simple procedures and easy to handle. 相似文献
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Anodic fluorination of 3-substituted benzofuran derivatives in a variety of fluoride salts resulted in the formation of three fluorinated products; two stereoisomers of 2,3-difluoro-2,3-dihydrobenzofuran (cis and trans) and cis-2-fluoro-3-hydroxy-2,3-dihydrobenzofuran derivatives. Dehydrofluorination of the main products, cis-difluoro derivatives, furnished the nonaromatic 2-fluoro-3-benzofuranyledene derivatives instead of the aromatic 2-fluorobenzofuran derivatives. 相似文献
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Akira Hirao Mayumi Hayashi Naoki Haraguchi 《Macromolecular rapid communications》2000,21(17):1171-1184
This article covers precise syntheses of well‐defined chain‐end and in‐chain functionalized polymers, multi‐functionalized polymers with a definite number of functional groups, star‐branched and graft polymers by recently developed methodologies using specially designed 1,1‐diphenylethylene (DPE) derivatives. The DPE derivatives include various substituted DPE derivatives with functional groups and their derivatives, DPE‐functionalized DPE derivatives, and well‐defined DPE‐functionalized macromonomers. The synthetic utility and importance of these DPE derivatives are described via such polymer syntheses. 相似文献
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Ernest D. Weiler Ramesh B. Petigara Martha H. Wolfersberger George A. Miller 《Journal of heterocyclic chemistry》1977,14(4):627-630
Bromination of 4-isothiazolin-3-ones, I, gave the 4-bromo derivatives, III, in good yields, while formation of 4,5-dibromo derivatives, IV, was much more difficult. In contrast, chlorination of I, even under mild conditions, gave primarily 4,5-dichloro derivatives, VI, and lesser amounts of the 4-chloro derivatives, V. Vigorous bromination of the 4-methyl analog of I gave the 5-bromo derivatives, VIII, whereas mild chlorination gave predominantly the 4,5,5-trichloro derivatives, X. 相似文献
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As an antitumor drug, because of its low efficacy and high toxicity, several modifications have been made on 5-fluorouracil (5-Fu). Some compounds have been found to be highly efficient and much less toxic for the treatment of various solid tumors1~4. Among them, deoxyfluridine (Furtulon) has been used clinically for several years. In our previous work, we have prepared several substituted derivatives of 5-Fu and the primary result shows that some of them have certain antitumor activity5,6. … 相似文献
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用手性的丙烯酸薄荷醇酯与原位生成的1,3-偶极试剂发生Diels-Alder反应, 得到一系列新的手性2,4-二酯基四氢吡咯衍生物,经氢化铝锂还原得到纯的手性 2,4-二羟甲基吡咯衍生物。并首次发现,在用Oxone氧化烯时,2,4-二羟甲基四 氢吡咯衍生物能有效地诱导烯烃发生环氧化反应,转化率达到定量。 相似文献
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Chi-yu Lee 《Applied biochemistry and biotechnology》1978,3(1):49-56
A simple method is described for the preparation of dextran-linked coenzyme derivatives. Several different 8-(6-aminohexyl)amino-adenine nucleotide coenzymes and their derivatives were covalently attached to dextran by incubation with bromohydroxypropyl derivatives of dextran at room temperature in an alkaline medium. The polymer-linked adenine nucleotide derivatives were separated from the free coenzyme derivatives by a Sephadex G-50 column. The prepared dextran derivatives have ligand densities ranging from 20 to 100 μmol/g of dextran derivatives depending on the conditions of coupling and derivatives. NMR studies revealed that proton resonances of the polymer-linked coenzymes exhibit short transverse relaxation times (T2) but long longitudinal relaxation times (T1) This phenomenon was interpreted in terms of the anisotropic motions of the dextran-bound coenzyme derivatives in which the fast axial motions and slow restricted transverse motions of the bound coenzyme derivatives are postulated. These observations could properly explain why the polymer-linked coenzymes exhibit lower biological activity, but similar binding affinity to most enzymes. 相似文献
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3-Cyanomethylidene oxindole derivatives were prepared in excellent yields utilizing DBU-promoted Knoevenagel condensation of isatin derivatives with active methylene reagents. The isolated products were then reacted with azaenamines via a DBU-promoted Michael addition to yield spirocyclic 2-oxindole derivatives with incorporated 6-amino-4H-pyridazines and their fused derivatives. 相似文献
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The acylation of some substituted 5-benzyl-1,2,4-triazoline-3-thiones both in the presence of triethylamine and in alkaline media gives N-substituted derivatives. N-Substituted derivatives were obtained by cyanoethylation, whereas S-substituted derivatives were obtained by alkylation. Bromination of the acyl derivatives gives disulfides. 相似文献
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Ishibashi K Nakajima K Sugioka Y Sugiyama M Hamada T Horikoshi H Nishi T 《Chemical & pharmaceutical bulletin》1999,47(2):226-240
A series of 2-phenylbenzofuran derivatives with a carbamoyl, alkylamino, or alkyloxy group at the 5 or 6 position of the benzofuran ring were synthesized and evaluated for rat and human testosterone 5 alpha-reductase inhibitory activities in vitro. Against rat enzyme, the carbamoyl derivatives had more potent inhibitory activities than the alkylamino or alkyloxy derivatives, and the 6-carbamoyl derivatives tended to be more potent than the 5-carbamoyl derivatives. Against human enzyme, the 6-substituted derivatives had more potent inhibitory activities than the 5-substituted derivatives. The 6-carbamoyl and 6-alkylamino derivatives tended to show stronger inhibitory activities against human type 1 enzyme than against type 2 enzyme, but they were not largely selective. 相似文献
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Giuliana Righi Emanuela Mandic’ Gaia Clara Mercedes Naponiello Paolo Bovicelli Ilaria Tirotta 《Tetrahedron》2012,68(14):2984-2992
The results obtained from a study on the stereochemical control in the dihydroxylation of the double bond of vinyl epoxides and their derivatives (bromo derivatives, azido derivatives and vinyl aziridines) are presented herein. A significant diastereoselectivity was observed for the bromo derivatives, azido derivatives and N-protected vinyl aziridines, whereas vinyl epoxides and unprotected vinyl aziridines showed no diastereoselectivity. The results obtained are generally consistent with the Kishi model. 相似文献
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研究了八种7-氨基香豆素衍生物在纯溶剂和二元溶剂体系中的荧光特性。这些衍生物因氨基上H的取代程度的不同,在溶液中可以形成两种不同的氢键。一种是由溶剂分子提供H,在香豆素环的2位氧原子上形成的氢键;另一种是由溶质分子提供H,在香豆素衍生物的7-氨基酸上形成的氢键。 相似文献
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《Journal of heterocyclic chemistry》2018,55(8):1917-1925
Ten new isoxazoline derivatives were synthesized from the reactions of benzonorbornadiene and homonorbornadiene derivatives with nitrile oxides formed from benzaldehyde and 4‐substituted benzaldehyde. Two new pyridazine derivatives were also synthesized from the reaction of the homonorbornadiene derivatives with 3,6‐di (2‐pyridyl)‐s‐tetrazine. It was seen that all cycloaddition reactions were realized as exo selectivity. Finally, γ‐Gauche effect in the isoxazoline derivatives was discussed. 相似文献