1.3‐Dipolare Additionen der Azomethin‐imine

Huisgen, Rolf; Grashey, Rudolf; Laur, Peter; Leitermann, Herta

doi:10.1002/ange.19600721209

Cited by 63 publications

(10 citation statements)

References 2 publications

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“…Intermediate 84 underwent δ-addition to the azomethine imine 57 to give 85 (Scheme 29). 43 Intramolecular Michael addition gave 86, which after [1,2] proton transfer afforded intermediate 87. Final elimination of the phosphine catalyst yielded the cycloadduct 81.…”

Section: Isoquinolinium-n-aryl Imidesmentioning

confidence: 99%

“…Azomethine imines are 1,3-dipoles of the allylic type, which present two types of resonance structures, iminium imide and diazonium ylide. [1][2][3][4] They are readily accessible as stable compounds or as intermediates for the synthesis of diverse dinitrogenated heterocycles by 1,3-dipolar cycloadditions (1,3-DC) under thermal or catalyzed conditions. [2][3][4][5][6][7][8][9][10][11][12] Numerous types of pharmaceuticals, agrochemicals and other biologically active compounds can be prepared by different types of [3 + 2] cycloadditions, mainly with alkenes and alkynes, but also high order cycloadditions, such as [3 + 3], [4 + 3] and [3 + 2 + 3], have been recently developed.…”

Section: General Introductionmentioning

confidence: 99%

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1,3-Dipolar cycloadditions of azomethine imines

2015

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Azomethine imines are considered 1,3-dipoles of the aza-allyl type which are transient intermediates and should be generated in situ but can also be stable and isolable compounds. They react with electron-rich and electron-poor olefins as well as with acetylenic compounds and allenoates mainly by a [3 + 2] cycloaddition but they can also take part in [3 + 3], [4 + 3], [3 + 2 + 2] and [5 + 3] with different dipolarophiles. These 1,3-dipolar cycloadditions (1,3-DC) can be performed not only under thermal or microwave conditions but also using metallo- and organocatalytic systems. In recent years enantiocatalyzed 1,3-dipolar cycloadditions have been extensively considered and applied to the synthesis of a great variety of dinitrogenated heterocycles with biological activity. Acyclic azomethine imines derived from mono and disubstituted hydrazones could be generated by prototropy under heating or by using Lewis or Brønsted acids to give, after [3 + 2] cycloadditions, pyrazolidines and pyrazolines. Cyclic azomethine imines, incorporating a C-N bond in a ring, such as isoquinolinium imides are the most widely used dipoles in normal and inverse-electron demand 1,3-DC allowing the synthesis of tetrahydro-, dihydro- and unsaturated pyrazolo[1,5-a]isoquinolines in racemic and enantioenriched forms with interesting biological activity. Pyridinium and quinolinium imides give the corresponding pyrazolopyridines and indazolo[3,2-a]isoquinolines, respectively. In the case of cyclic azomethine imines with an N-N bond incorporated into a ring, N-alkylidene-3-oxo-pyrazolidinium ylides are the most popular stable and isolated dipoles able to form dinitrogen-fused saturated and unsaturated pyrazolopyrazolones as racemic or enantiomerically enriched compounds present in many pharmaceuticals, agrochemicals and other useful chemicals.

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Section: Isoquinolinium-n-aryl Imidesmentioning

confidence: 99%

Section: General Introductionmentioning

confidence: 99%

1,3-Dipolar cycloadditions of azomethine imines

2015

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“…Briefly, preparations for corannulene, [ 13 ] corannulene bromide, [ 14 ] and ethynylcorannulene [ 15 ] were followed the reported methods. As a new finding in the current study, unlike the thermal Huisgen 1,3‐dipolar cycloaddition, [ 16 ] the copper‐catalyzed click chemistry of ethynylcorannulene with sugar azides allows the selective production of the 1,4‐disubstituted regioisomers in a very high yield ( Figure A). In addition, the anomeric stereochemistry of the sugar appendants in each Cor‐sugars was determined to be a pure single isomer by 1H NMR analysis of the C1‐proton in the hexose moiety.…”

Section: Resultsmentioning

confidence: 95%

An Unrevealed Molecular Function of Corannulene Buckybowl Glycoconjugates in Selective Tumor Annihilation by Targeting the Cancer‐Specific Warburg Effect

et al. 2022

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The biomedical application of corannulene 𝝅-bowls is historically limited by low solubility and bioavailability despite the potential in their unique electronic properties for new functional materials. Herein, the unexpected role and molecular mechanism of Corranulene 𝝅-bowls are uncovered in biomedical applications as an effective anticancer agent for Warburg effect mediated selective tumor targeting. The corannulene triazolyl monosaccharides Cor-sugars exhibit highly potent cytotoxicity against human cancer cells and effectively inhibit xenograft growth of hyperglycolytic tumors. Particularly, the galactose-conjugated Cor-gal exhibits superior in vivo anticancer efficacy in A549 tumor models with outstanding safety profile compared to doxorubicin. Moreover, the combined treatment of Cor-gal with immune checkpoint inhibitor results in an effective synergy in treating H460 human lung carcinoma. An uptake mechanism study reveals that Cor-sugars exploit tumor-specific glucose transporter glucose transporter 1 (GLUT1) for targeted cell delivery and intra-tumoral accumulation through the cancer-specific Warburg effect. Their significant anticancer activity is attributed to multiphasic DNA-binding and cell cycle alteration effects. This study uncovers new molecular properties of corannulene buckybowl and enabling their potential new applications in biomedical engineering.

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“…LXIX azomethine imines (50). It is possible that these two structures contribute rather more to the actual electronic distribution than has generally been considered…”

Section: LXVIIImentioning

confidence: 97%