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1.
The first intermolecular 1,3-dipolar cycloaddition of diazocarbonyl compounds with alkynes was developed by using an InCl(3) catalyzed cycloaddition in water. The reaction was found to proceed by a domino 1,3-dipolar cycloaddition-hydrogen (alkyl or aryl) migration. 相似文献
2.
为研究纳米线的形成机理,通过密度泛函理论(DFT)研究了贵金属(铂)在脱质子化1,3-环加成石墨烯上的吸附.研究发现:(1)吸附在1,3-环加成石墨烯上的铂原子引起该结构的脱质子化过程并形成脱质子化1,3-环加成石墨烯;(2)贵金属在脱质子化1,3-环加成石墨烯上的锚定位是氮原子邻位的碳原子,这在邻位碳原子的平均巴德电荷分析(高达1.0e)中得到进一步的证实;(3)铂原子在相邻的脱质子化吡啶炔单元上形成金属纳米线,并且该纳米线比相应的铂团簇稳定得多;(4)电子结构分析表明,铂的吸附并没有从根本上改变脱质子化1,3-环加成石墨烯的电子性质.铂金属的掺杂使得Pt6团簇吸附形成的复合物呈现金属性,而Pt6纳米线形成的复合物则为半金属性. 相似文献
3.
The title compounds 5 can be easily obtained by two alternative procedures: 1,3-dipolar cycloaddition to benzamidocinnamates 3 prepared by methanolysis of the corresponding oxazolones 1 or methanolysis of the spirooxazolones 4 synthesized by 1,3-dipolar cycloaddition to oxazolones 1 . Both reaction sequences show the same stereo and regioselectivity. 相似文献
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6.
Cheng Y Liu MF Fang DC Lei XM 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(15):4282-4292
2-aryl thiocarbamoyl benzimidazolium and imidazolinium inner salts derived from benzimidazole and imidazoline carbenes are unique ambident C-C-S and C-C-N 1,3-dipolar systems, which undergo highly efficient and site-selective cycloaddition reactions with dimethyl acetylenedicarboxylate or dibenzoylacetylene to furnish spiro(imidazole-2,3'-thiophene) derivatives in excellent yields. When treated with ethyl propiolate, methyl acrylate or acrylonitrile, spiro(imidazole-2,3'-pyrrole) derivatives were formed in good yields. Theoretical studies revealed an asynchronous concerted mechanism for both the C-C-S and C-C-N 1,3-dipolar cycloaddition reactions. The site selectivity in the [3+2] cycloaddition reaction of ambident 1,3-dipoles was predictably regulated by both the electronic and steric effects of dipolarophiles. 相似文献
7.
利用1,3-偶极环加成反应对卟啉大环进行修饰是近年来卟啉研究的一个新热点。环加成产物因在可见光谱长波段范围的特征吸收,在构筑人工光反应体系和用作光动力疗法中的光敏剂等领域有重要应用价值。本文综述了1,3-偶极环加成反应在修饰卟啉化合物方面的研究进展,包括:卟啉作为亲偶极体能与甲亚胺叶立德、硝酮、重氮烷、羰基叶立德、腈氧化物等1,3-偶极子反应生成各种新型杂环稠合卟吩类化合物;卟啉化合物作为1,3-偶极子能与C60等亲偶极体反应,生成β位取代的各种新型卟啉化合物;以及扩展卟啉也可以作为亲偶极体与甲亚胺偶极子发生1,3-偶极环加成反应等。 相似文献
8.
1,3-dipolar cycloaddition reactions of nitrones with alkenes and alkynes are well-studied reactions in solution-phase organic chemistry. However, the number of studies concerned with their application in solid-phase organic synthesis is rather low compared to other 1,3-dipoles, e.g. azides or nitrile oxides. This tutorial review aims to summarise the main approaches towards the application of nitrones in 1,3-dipolar cycloaddition reactions on solid supports in addition to subsequent transformations with polymer-bound isoxazolidines and reactions using polymer-bound catalysts. 相似文献
9.
The new spirocyclic compounds, spiropyrrolidinyl-benzoisothiazoline derivatives were synthesized by the 1,3-dipolar cycloaddition of benzoisothiazole-2,2-dioxide-3-ylidenes and azomethine ylide. The stereochemistry of 1,3-dipolar cycloaddition as well as the stereochemistry of Knoevenagel condensation of benzoisothiazole-2,2-dioxide with aldehydes were studied. 相似文献
10.
The polymer-supported liquid-phase synthesis of small organic molecules has been a subject of intense research activity. 1,2,4-Triazoles are well known for their antifungal[1] and antibacterial[2] activities. This moiety was also found in potent agonist or antagonist receptor lingands. The synthesis of substituted 1,2,4-triazoles via 1,3-dipolar cycloaddition of imines with nitrilimines is well documented.[3] Herein, we would like to report the first liquid-phase synthesis of 1,3,4,5-tetraaryl-4,5-dihydro-1,2,4-triazoles through a 1,3-dipolar cycloaddition of imines with nitrilimines on PEG support. 相似文献
11.
1,3-Dipolar cycloaddition of organic azides 1, 2, or 3 to acetylenic amides 4 or 5 under solvent-free microwave irradiation produced the corresponding N-substituted C-carbamoyl-1,2,3-triazoles 7a-12a in good to excellent yields. Under similar reaction conditions, 1,3-dipolar cycloaddition of diazide 6 and acetylenic amide 4 gave the azido-triazole 13a. 相似文献
12.
He L Chen XH Wang DN Luo SW Zhang WQ Yu J Ren L Gong LZ 《Journal of the American Chemical Society》2011,133(34):13504-13518
A variety of chiral bisphosphoric acids derived from binaphthols have been evaluated for enantioselective 1,3-dipolar cycloaddition reactions, revealing that the feature of the linker in the catalysts exerted great impact on the stereoselectivity. Among them, the oxygen-linked bisphosphoric acid 1a provided the highest level of stereoselectivity for the 1,3-dipolar cycloaddition reaction tolerating a wide range of substrates including azomethine ylides, generated in situ from a broad scope of aldehydes and α-amino esters, and various electron-deficient dipolarophiles such as maleates, fumarates, vinyl ketones, and esters. This reaction actually represents one of the most enantioselective catalytic approaches to access structurally diverse pyrrolidines with excellent optical purity. Theoretical calculations with DFT method on the formation of azomethine ylides and on the transition states of the 1,3-dipolar cycloaddition step showed that the dipole and dipolarophile were simultaneously activated by the bifunctional chiral bisphosphoric acids through the formation of hydrogen bonds. The effect of the bisphosphoric acids on reactivity and stereochemistry of the three-component 1,3-dipolar cycloaddition reaction was also theoretically rationalized. The bisphosphoric acid catalyst 1a may take on a half-moon shape with the two phosphoric acid groups forming two intramolecular hydrogen bonds. In the case of maleates, one phosphate acts as a base to activate the 1,3-dipole, and simultaneously, the two hydroxyl groups in the catalyst 1a may respectively form two hydrogen bonds with the two ester groups of maleate to make it more electronically deficient as a much stronger dipolarophile to participate in a concerted 1,3-dipolar cycloaddition with azomethine ylide. However, in the cases involving acrylate and fumarate dipolarophiles, only one hydroxyl group forms a hydrogen bond with the ester functional group to lower the LUMO of the C-C double bond and another one is remained to adjust the acidity and basicity of two phosphoric acids to activate the dipole and dipolarophile more effectively. 相似文献
13.
Ethylene trithiocarbonate reacted with dimethyl acetylenedicarboxylate to furnish tetramethyl thiopyran-4-spiro-2'-(1,3- dithiolane)-2,3,5,6-tetracarboxylate,a new thiopyran-4-spiro-2'-(1,3-dithiolane) heterocyclic compound,as the minor product together with the major product dimethyl 2-thioxo-1,3-dithiole-4,5-dicarboxylate.The new heterocycle was probably formed through a[2 + 2]cycloaddition between ethylene trithiocarbonate and dimethyl acetylenedicarboxylate followed by a 1,3-dipolar cycloaddition or[... 相似文献
14.
A.R. Suresh Babu 《Tetrahedron letters》2008,49(31):4618-4620
A facile one-pot synthesis of novel steroidal dispiropyrrolidines has been accomplished by 1,3-dipolar cycloaddition reaction of various azomethine ylides derived from isatin/acenaphthenequinone/ninhydrin and sarcosine with various estrone derivatives as dipolarophiles, in good yield. The effect of various solvents on the 1,3-dipolar cycloaddition reaction are also studied. 相似文献
15.
Andrzej Wolan Justyna A. Kowalska-Six Holisoa Rajerison Michèle Césario Marie Cordier Yvan Six 《Tetrahedron》2018,74(38):5248-5257
Two types of bicyclic N-cyclopropyl glycine ester derivatives have been prepared and put under scrutiny as possible precursors of azomethine ylides. The results demonstrate that they can indeed participate in 1,3-dipolar cycloaddition reactions with dipolarophiles, as illustrated in the cases of phenyl vinyl sulfone, N-phenylmaleimide, diethyl fumarate and diethyl maleate. The relative configurations of the major diastereoisomers produced are consistent with the predicted generation of azomethine ylide species, reacting in concerted cycloaddition processes. This unprecedented way of generating such 1,3-dipoles provides access to functionalised pyrrolizidine and pyrrolidine derivatives, that would be difficult to make directly by more classic methods. It was also found that using phenyl vinyl sulfone or N-phenylmaleimide as the dipolarophile reactant, a domino nucleophilic conjugate addition/1,3-dipolar cycloaddition process may operate competitively. 相似文献
16.
Ming-Chang P. Yeh Chi-Fen Jou Wei-Tzou Yeh Da-Yu Chiu N. Ravi Kumar Reddy 《Tetrahedron》2005,61(2):493-500
Intramolecular 1,3-dipolar cycloaddition of cyclo-1,3-diene- and -1,3,5-triene-tethered nitrile oxides gave tricyclic isoxazolines as a single stereoisomer in most cases. The relative stereochemistry of tricycle-fused isoxazolines resulting from 1,3-dipolar cycloaddition of cyclo-1,3-diene-tethered nitrile oxides is cis-cis, whereas from cyclohepta-1,3,5-triene-tethered nitrile oxides the cis-trans isomer predominates. 相似文献
17.
Georgios Rotas 《Tetrahedron letters》2009,50(4):398-2954
The tether-directed regioselective synthesis of equatorial bis-adducts of [60]fullerene via the 1,3-dipolar cycloaddition reaction of azomethine ylides is reported. A mono-[60]fulleropyrrolidine adduct, derived via 1,3-dipolar cycloaddition of azomethine ylides generated in situ upon thermal condensation of triphenylamine bis-aldehyde and an α-amino acid, was isolated and further reacted to yield, exclusively and selectively, the equatorial bis-adduct, which is structurally characterized by appropriate spectroscopic means. 相似文献
18.
A new set of phosphorus-containing chiral ligands has been synthesized and used with silver(I) for the catalytic asymmetric 1,3-dipolar cycloaddition reaction of azomethine ylides. One of these ligands (POFAM6) was found to produce an effective catalyst for the asymmetric 1,3-dipolar cycloaddition reaction of azomethine ylides with electron deficient dipolarophiles to form pyrrolidines in up to 97% yield and 89% ee. 相似文献
19.
A. M. Starosotnikov D. V. Khakimo M. A. Bastrakov S. Yu. Pechenkin S. A. Shevelev T. S. Pivina 《Chemistry of Heterocyclic Compounds》2011,47(2):215-221
Synthetic approaches to 1,3-dipolar cycloaddition of N-methylazomethinylid to mononitrobenzazole are described. The geometric
and electronic structures have been studied by quantum chemical methods (HF/STO-3 G and B3LYP/6-31 G*) and the reactivity
indexes of compounds have been estimated. It was shown that 1,3-dipolar cycloaddition of N-methylazomethinylid to the dipolarophile
has a polar character and proceeds in accordance with the normal (noninversion) electronic distribution. 相似文献