Regioselective α-arylation of coumarins and 2-pyridones with phenylhydrazines under transition-metal-free conditions

Chauhan, Prem M. S.; Ravi, Makthala; Singh, Satyawan; Prajapati, Prashant; Yadav, Prem P.

doi:10.1039/c5ra20954d

Cited by 53 publications

(26 citation statements)

References 77 publications

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“…This synthetic procedure achieved transition metal free arylation of pyrrole in a eco-friendly way. The synthetic process started from the reaction of phenylhydrazine hydrochloride salt with NaOH to rapidly forma free phenylhydrazine, a slow oxidation with air to produce aryl radical 15 . Aryl radical X reacted with N-methyl pyrrole at room temperature to form allyl radical X which was supported by radical resonance after that losing a single electron loosing with air oxidation and eliminating a proton resulted acrylate pyrrole 16 .…”

Section: Resultsmentioning

confidence: 99%

Determination of the inhibitory effects of N-methylpyrrole derivatives on glutathione reductase enzyme

Kocaoğlu

Talaz

Çavdar

et al. 2018

Journal of Enzyme Inhibition and Medicinal Chemistry

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Glutathione reductase (GR) is a crucial antioxidant enzyme which is responsible for the maintenance of antioxidant GSH molecule. Antimalarial effects of some chemical molecules are attributed to their inhibition of GR, thus inhibitors of this enzyme are expected to be promising candidates for the treatment of malaria. In this work, GR inhibitory properties of N-Methylpyrrole derivatives are reported. It was found that all compounds have better inhibitory activity than the strong GR inhibitor N,N-bis(2-chloroethyl)-N-nitrosourea, especially three molecules, 8 m, 8 n, and 8 q, were determined to be the most powerful among them. Findings of our study indicates that these Schiff base derivatives are strong GR inhibitors which can be used as leads for designation of novel antimalarial candidates.

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Section: Resultsmentioning

confidence: 99%

Determination of the inhibitory effects of N-methylpyrrole derivatives on glutathione reductase enzyme

Kocaoğlu

Talaz

Çavdar

et al. 2018

Journal of Enzyme Inhibition and Medicinal Chemistry

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“…3-(4-fluorophenyl)-6-methyl-2H-chromen-2-one (23) . (Chauhan et al, 2016 ) Yield 74%; 1 H-NMR (400 MHz, d 6 -DMSO) δ: 2.38 (s, 3H, CH 3 -Ph), 7.27-7.35 (m, 3H, H-3', H-5', H-8), 7.43 (dd, 1H, J 3 = 8.5 Hz, J 4 = 2.1 Hz, H-7), 7.55 (d, 1H, J 4 = 1.4 Hz, H-5), 7.77 (dd, 2H, J HF = 5.7 Hz, J H−H = 9.0 Hz, H-2', H6'), 8.18 (s, 1H, H-4); 13 C-NMR (100.6 MHz, d 6 -DMSO) δ: 20.26, 115.11 (d, J H−F = 21.5 Hz), 115.64, 119.16, 125.76, 128.20, 130.70 (d, J H−F = 8.4 Hz), 131.10 (d, J H−F = 3.2 Hz), 132,61, 133.80, 140.48, 151.10, 159.82, 162.17 (d, J H−F = 245 Hz); HRMS (ESI): Calc for C 16 H 11 F 1 O 2 Na 1 [M + Na] + : 277.06408, found 277.06390; Elemental anal. for C 16 H 11 F 1 O 2 , calc C% 75.58, H% 4.36, found C% 75.42, H% 4.33.…”

Section: Methodsmentioning

confidence: 99%

Structure-Activity Relationship Analysis of 3-Phenylcoumarin-Based Monoamine Oxidase B Inhibitors

et al. 2018

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Monoamine oxidase B (MAO-B) catalyzes deamination of monoamines such as neurotransmitters dopamine and norepinephrine. Accordingly, small-molecule MAO-B inhibitors potentially alleviate the symptoms of dopamine-linked neuropathologies such as depression or Parkinson's disease. Coumarin with a functionalized 3-phenyl ring system is a promising scaffold for building potent MAO-B inhibitors. Here, a vast set of 3-phenylcoumarin derivatives was designed using virtual combinatorial chemistry or rationally de novo and synthesized using microwave chemistry. The derivatives inhibited the MAO-B at 100 nM−1 μM. The IC50 value of the most potent derivative 1 was 56 nM. A docking-based structure-activity relationship analysis summarizes the atom-level determinants of the MAO-B inhibition by the derivatives. Finally, the cross-reactivity of the derivatives was tested against monoamine oxidase A and a specific subset of enzymes linked to estradiol metabolism, known to have coumarin-based inhibitors. Overall, the results indicate that the 3-phenylcoumarins, especially derivative 1, present unique pharmacological features worth considering in future drug development.

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“…13 C{1H} NMR (100 MHz, CDCl 3 ) δ 182. 4,160.4,147.3,134.2,134.2,133.8,132.8,131.7,127.2,127.0,125.7,116.3,116.0,113.6,55.5. HRMS (ESI+) 5, 181.6, 160.4, 148.0, 147.0, 134.1, 134.1, 133.8, 132.9, 131.8, 131.5, 129.0, 127.5, 127.1, 127.0, 125.8, 113.5, 55.5 2, 182.1, 165.6, 163.0, 156.7, 138.1, 138.0, 134.6, 133.6, 132.3, 131.8, 129.8, 128.4, 127.0, 126.8, 122.8, 118.0, 117.8 2, 181.6, 156.8, 148.2, 147.8, 135.9, 134.5, 134.2, 133.8, 133.7, 133.5, 132.7, 132.2, 131.7, 130.7, 130.5, 129.8, 129.0, 129.0, 128.3, 128.0, 127.6, 127.1, 127.0, 126.7 5,182.0,160.3,159.6,148.2,146.4,134.2,134.0,133.7,132.8,132.4,132.3,131.7,127.0,126.9,125.8,123.9,114.6,113.4,55.4.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

“…3 Recently, Liu and co-workers generated N,N′-diacylhydrazine from (bis(trifluoroacetoxy)iodo)benzene (PIFA) and N-acetylphenylhydrazide at a mild temperature. 4 The phenyl radical (generated from the N-acetyl-N′-phenylhydrazide under oxygen in PIFA) plays a crucial role in the transformation. 4 Aryl radicals are also generated by treating aryl hydrazines or aryl hydrazine hydrochlorides with bases (such as pyridine, sodium hydroxide, and potassium carbonate) in the presence of air.…”

Section: ■ Introductionmentioning

confidence: 99%

“…4 The phenyl radical (generated from the N-acetyl-N′-phenylhydrazide under oxygen in PIFA) plays a crucial role in the transformation. 4 Aryl radicals are also generated by treating aryl hydrazines or aryl hydrazine hydrochlorides with bases (such as pyridine, sodium hydroxide, and potassium carbonate) in the presence of air. 5a−c These aryl radicals are eventually quenched by various heteroaromatic or heterocycle building blocks, such as pyrrolidine, pyridine, chromones, etc., to provide the corresponding arylated species.…”

Section: ■ Introductionmentioning

confidence: 99%

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Generation of Aryl Radicals from Aryl Hydrazines via Catalytic Iodine in Air: Arylation of Substituted 1,4-Naphthoquinones

2020

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Arylated building blocks or heterocycles are key to myriad applications, including pharmaceutical drug discovery, materials sciences, and many more. Herein, we have reported a mild and efficient strategy for generation of aryl radicals by reacting appropriate aryl hydrazines with catalytic iodine in open air. The aryl radicals were quenched by diversely substituted 1,4napthoquinones present in the reaction mixture to afford diversely substituted 2,3-napthoquinones in moderate to excellent yield. Control experiments provided insights into the putative reaction mechanism.

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Regioselective α-arylation of coumarins and 2-pyridones with phenylhydrazines under transition-metal-free conditions

Abstract: A transition-metal-free regioselective α-arylation of coumarins and 2-pyridones has been accomplished by the reaction of phenylhydrazines with coumarins or 2-pyridones.

Cited by 53 publications

References 77 publications

Determination of the inhibitory effects of N-methylpyrrole derivatives on glutathione reductase enzyme

Determination of the inhibitory effects of N-methylpyrrole derivatives on glutathione reductase enzyme

Structure-Activity Relationship Analysis of 3-Phenylcoumarin-Based Monoamine Oxidase B Inhibitors

Generation of Aryl Radicals from Aryl Hydrazines via Catalytic Iodine in Air: Arylation of Substituted 1,4-Naphthoquinones

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