Lewis acid catalysis of photochemical reactions. 8. Photodimerization and cross-cycloaddition of coumarin

Lewis, Frederick D.; Barancyk, Steven V.

doi:10.1021/ja00205a015

Cited by 183 publications

(144 citation statements)

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“…The vibrations ν(N-H) disappeared in the spectra of the four complexes, indicating that the ligand was deprotonated. The novel bands near 560 cm -1 for the complexes were assigned to ν(M-O), and the weaker peaks near 470 cm -1 were assigned to ν(M-N), respectively (23,24), consistent with the results of X-ray diffraction analysis.…”

Section: Resultssupporting

confidence: 83%

Synthesis, characterization and anticancer activities of transition metal complexes with a nicotinohydrazone ligand

et al. 2017

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Abstract. The reaction of divalent transition metal salts and (E)-N'-(1-(pyridin-2-yl)ethylidene)nicotinohydrazide (penh) led to the formation of [Mn(penh) 2 ] (complex 1), [Co(penh) 2 ] (complex 2), [Cu(penh) 2 ] (complex 3) and [Cd (penh) 2 ] (complex 4) complexes. The four complexes were characterized using elemental analyses, infrared spectra and single-crystal X-ray diffraction analyses. Subsequently, the complexes were used for in vitro cell level experiments to determine potential antitumor effects. The results demonstrated that the complexes exhibited a similar structure; however, they were crystallized with distinct space groups. In comparison with the uncomplexed penh ligand, all four complexes were able to markedly decrease the proliferation rate of various types of tumor cell, including the human lung cancer cell line A549, human gastric cancer cell line BGC823 and human esophageal cancer cell line Eca109, in a concentration-dependent manner. Furthermore, the complexes promoted tumor cell apoptosis, as demonstrated in the apoptosis assay, and this was confirmed using electrophoresis. IntroductionHydrazide-hydrazone derivatives are an important class of biologically active molecules, which have attracted the attention of medicinal chemists due to their wide-ranging pharmacological properties and their potential application as antitumor, antineoplastic, antiviral and anti-inflammatory agents (1-6).In particular, aroylhydrazone complexes of transition metals are known to provide useful models for the elucidation of the underlying molecular mechanism of enzyme inhibition by hydrazine derivatives (7) and for their potential pharmacological application (8,9). Hydrazone derivatives of isoniazid and other hydrazides have been reported to exhibit marked antimicrobial activity (10-14). Furthermore, a number of substituted hydrazone derivatives have been synthesized and evaluated for their antitumor activity, with certain promising results having been reported (15-17).The aim of the present study was to develop potent anticancer agents. (E)-N'-(1-(pyridin-2-yl)ethylidene) nicotinohydrazide (penh), and [Mn(penh) 2 ] (complex 1), [Co (penh) 2 ] (complex 2), [Cu(penh) 2 ] (complex 3) and [Cd(penh) 2 ] (complex 4) metal complexes were synthesized, and their cytotoxicity against human lung cancer (A549), human gastric cancer (BGC823) and human esophageal cancer (Eca109) cell lines was investigated. Materials and methodsMaterials. All starting materials were obtained commercially and used as received. The A549 human lung cancer, BGC823 human gastric cancer and Eca109 human esophageal cancer cell lines were obtained from the Cell Culture Center of the Basic Institute of Medical Sciences (Peking Union Medical College, Beijing, China). Cell culture reagents were purchased from Gibco (Thermo Fisher Scientific, Inc., Waltham, MA, USA). An Annexin V/propidium iodide (PI) double staining kit was purchased from BD Biosciences (Franklin Lakes, NJ, USA). MTT and dimethyl sulfoxide (DMSO) were purchased from Sigma-Aldrich (Merc...

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Section: Resultssupporting

confidence: 83%

Synthesis, characterization and anticancer activities of transition metal complexes with a nicotinohydrazone ligand

et al. 2017

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“…Parallel experimental studies have been carried out on the BF 3 adducts with benzaldehyde [15], other aromatic aldehydes [18], cinnamate esters [19,20], and coumarin [21].…”

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The vibrational spectra of the boron halides and their molecular complexes. Part 13. Ab initio studies of the complexes of boron trifluoride with formaldehyde and some of its analogs

Ford

2011

Int J of Quantum Chemistry

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ABSTRACT:The structure, the interaction energy, and the vibrational spectrum of the electron donor-acceptor complex formed between boron trifluoride, as a Lewis acid, and formaldehyde, as a Lewis base, have been determined by means of ab initio calculations at the second-order level of Møller-Plesset perturbation theory, using a triple-zeta basis set with polarization and diffuse functions on all atoms. The object was to examine the differences in the properties of the complexes formed between boron trifluoride and an oxygen base containing oxygen in the sp 2 hybrid state with those of some sp 3 oxygen bases studied earlier. The investigation has then been extended to include the related bases thioformaldehyde and methanimine, to assess the effect of substituting the oxygen atom by a sulphur atom or an imino group. A further range of formaldehyde analogs, containing one and two methyl groups, one and two fluorine atoms, and one methyl group and one fluorine atom, has also been included. The preferred structure of each complex has been identified. The computed data have been compared, and the complex properties correlated with some relevant physical properties of the bases.

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“…Erste Vorversuche ergaben, dass unsubstituiertes Thioxanthon, dessen Triplettenergie zu E T = 264 kJ mol À1 bestimmt wurde, [48] [53] Dieser ungewçhnliche Befund basiert auf der Tatsache, dass Cumarin in Abwesenheit von Katalysatoren keine Photocycloaddition eingeht, weil die Deaktivierung des angeregten Zustands außerordentlich schnell erfolgt.…”

Section: Xanthone Und Thioxanthoneunclassified

Enantioselektive Katalyse photochemischer Reaktionen

et al. 2015

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Die Natur des angeregten Zustands macht die Entwicklung chiraler Katalysatoren für enantioselektive photochemische Reaktionen zu einer enormen Herausforderung. Die Absorption eines 400‐nm‐Photons entspricht einer Energieaufnahme von etwa 300 kJ mol−1. Es bedarf innovativer Konzepte, um in einem derart großen Abstand vom Grundzustand Reaktionspfade zu eröffnen, die gezielt zu einem Enantiomer einer chiralen Verbindung führen. Hier werden die beiden wesentlichen Vorgehensweisen für homogen katalysierte, enantioselektive Prozesse diskutiert. Im ersten Teil werden chirale Photokatalysatoren besprochen, die in den photochemischen Schlüsselschritt eingreifen und in diesem Schritt eine asymmetrische Induktion bewirken. Im zweiten Teil werden Reaktionen vorgestellt, in denen die photochemische Anregung durch einen achiralen Katalysator erfolgt und die asymmetrische Induktion durch einen zweiten chiralen Katalysator gewährleistet wird (duale Katalyse).

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Lewis acid catalysis of photochemical reactions. 8. Photodimerization and cross-cycloaddition of coumarin

Cited by 183 publications

References 0 publications

Synthesis, characterization and anticancer activities of transition metal complexes with a nicotinohydrazone ligand

Synthesis, characterization and anticancer activities of transition metal complexes with a nicotinohydrazone ligand

The vibrational spectra of the boron halides and their molecular complexes. Part 13. Ab initio studies of the complexes of boron trifluoride with formaldehyde and some of its analogs

Enantioselektive Katalyse photochemischer Reaktionen

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