Aryl radical-induced desulfonylative ipso-substitution of diaryliodonium salts: an efficient route to sterically hindered biarylamines

2020 ◽  
Vol 56 (42) ◽  
pp. 5697-5700 ◽  
Author(s):  
Huangguan Chen ◽  
Limin Wang ◽  
Jianwei Han
Keyword(s):  
Reaction Pathway ◽  
Aryl Radical ◽  
Ipso Substitution ◽  
Diaryliodonium Salts ◽  
Efficient Route ◽  
Sterically Hindered ◽  
Induced Reaction

By using vicinal aryl sulfonamide-substituted diaryliodonium salts, a cascade of desulfonylation/aryl migration was promoted by triethylamine in synthesis of sterically hindered biarylamines, which operated via a radical-induced reaction pathway.

scholarly journals Catalytic Antioxidant Activity of Bis-Aniline-Derived Diselenides as GPx Mimics

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4446
Author(s):  
Giancarlo V. Botteselle ◽  
Welman C. Elias ◽  
Luana Bettanin ◽  
Rômulo F. S. Canto ◽  
Drielly N. O. Salin ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Hydrogen Bond ◽  
Electronic Properties ◽  
Partial Charge ◽  
Amino Group ◽  
Diphenyl Diselenide ◽  
Charge Delocalization ◽  
Ipso Substitution ◽  
Efficient Route ◽  
Catalytic Performances

Herein, we describe a simple and efficient route to access aniline-derived diselenides and evaluate their antioxidant/GPx-mimetic properties. The diselenides were obtained in good yields via ipso-substitution/reduction from the readily available 2-nitroaromatic halides (Cl, Br, I). These diselenides present GPx-mimetic properties, showing better antioxidant activity than the standard GPx-mimetic compounds, ebselen and diphenyl diselenide. DFT analysis demonstrated that the electronic properties of the substituents determine the charge delocalization and the partial charge on selenium, which correlate with the catalytic performances. The amino group concurs in the stabilization of the selenolate intermediate through a hydrogen bond with the selenium.

scholarly journals Hydrogen sulfide bypasses the rate-limiting oxygen activation of heme oxygenase

2018 ◽  
Vol 293 (43) ◽  
pp. 16931-16939 ◽  
Author(s):  
Toshitaka Matsui ◽  
Ryota Sugiyama ◽  
Kenta Sakanashi ◽  
Yoko Tamura ◽  
Masaki Iida ◽  
...  
Keyword(s):  
Heme Oxygenase ◽  
Mammalian Cells ◽  
Culture Media ◽  
Reaction Pathway ◽  
Hypoxic Conditions ◽  
Research Areas ◽  
Generating Capacity ◽  
Rate Limiting ◽  
Sulfur Containing ◽  
Induced Reaction

Discovery of unidentified protein functions is of biological importance because it often provides new paradigms for many research areas. Mammalian heme oxygenase (HO) enzyme catalyzes the O2-dependent degradation of heme into carbon monoxide (CO), iron, and biliverdin through numerous reaction intermediates. Here, we report that H2S, a gaseous signaling molecule, is part of a novel reaction pathway that drastically alters HO's products, reaction mechanism, and catalytic properties. Our prediction of this interplay is based on the unique reactivity of H2S with one of the HO intermediates. We found that in the presence of H2S, HO produces new linear tetrapyrroles, which we identified as isomers of sulfur-containing biliverdin (SBV), and that only H2S, but not GSH, cysteine, and polysulfides, induces SBV formation. As BV is converted to bilirubin (BR), SBV is enzymatically reduced to sulfur-containing bilirubin (SBR), which shares similar properties such as antioxidative effects with normal BR. SBR was detected in culture media of mouse macrophages, confirming the existence of this H2S-induced reaction in mammalian cells. H2S reacted specifically with a ferric verdoheme intermediate of HO, and verdoheme cleavage proceeded through an O2-independent hydrolysis-like mechanism. This change in activation mode diminished O2 dependence of the overall HO activity, circumventing the rate-limiting O2 activation of HO. We propose that H2S could largely affect O2 sensing by mammalian HO, which is supposed to relay hypoxic signals by decreasing CO output to regulate cellular functions. Moreover, the novel H2S-induced reaction identified here helps sustain HO's heme-degrading and antioxidant-generating capacity under highly hypoxic conditions.

scholarly journals Alcohol-Initiated Dediazoniation of Aryldiazonium Ions to Aryl Radicals: A Simple and Efficient Route to Arylboronates

2018 ◽  
Vol 42 (9) ◽  
pp. 481-485
Author(s):  
Xiulian Zhang ◽  
Zhicheng Zhang ◽  
Yongbin Xie ◽  
Yujie Jiang ◽  
Ruibo Xu ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Bond Formation ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Aryl Radical ◽  
Radical Species ◽  
Aryl Radicals ◽  
Efficient Access ◽  
Efficient Route ◽  
Operational Simplicity

A simple and efficient access to arylboronates was achieved with methanol-initiated borylation of aryldiazonium salts. Reduction of aryldiazonium ions by single electron transfer from methanol affords aryl radical species, which undergo a subsequent C–B bond formation with bis(pinacolato)diboron. This highly practical borylation process, which can be carried out on the gram-scale, enjoys operational simplicity as well as mild and catalyst-free conditions.

ChemInform Abstract: A New Efficient Route to (.+-.)-Physostigmine (IVa) and (.+-.)-Physovenine (IVb) by Means of 5-exo Selective Aryl Radical Cyclization of O-Bromo-N-acryloylanilides (II).

ChemInform ◽  
2010 ◽  
Vol 31 (27) ◽  
pp. no-no
Author(s):  
Hiroyuki Ishibashi ◽  
Tetsuya Kobayashi ◽  
Noriko Machida ◽  
Osamu Tamura
Keyword(s):  
Radical Cyclization ◽  
Aryl Radical ◽  
Efficient Route

Coupling of an aryl radical with a nucleophile and the reaction pathway

1982 ◽  
Vol 59 (4) ◽  
pp. 310 ◽  
Author(s):  
Roberto A. Rossi
Keyword(s):  
Reaction Pathway ◽  
Aryl Radical

A New Efficient Route to (±)-Physostigmine and (±)-Physovenine by Means of 5-exo Selective Aryl Radical Cyclization of o-Bromo-N-acryloylanilides

Tetrahedron ◽  
2000 ◽  
Vol 56 (11) ◽  
pp. 1469-1473 ◽  
Author(s):  
Hiroyuki Ishibashi ◽  
Tetsuya Kobayashi ◽  
Noriko Machida ◽  
Osamu Tamura
Keyword(s):  
Radical Cyclization ◽  
Aryl Radical ◽  
Efficient Route

scholarly journals Copper-Catalyzed Selective Arylation of Oxadiazolones by Diaryliodonium Salts

2021 ◽  
Author(s):  
Natalia Soldatova ◽  
Artem Semenov ◽  
Kirill Geyl ◽  
Sergey Baykov ◽  
Anton Shetnev ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Structural Study ◽  
High Potential ◽  
Steric Effects ◽  
Mild Conditions ◽  
Diaryliodonium Salts ◽  
Steric Accessibility ◽  
Sterically Hindered ◽  
High Yields ◽  
Synthetic Application

The direct N-arylation of cyclic amides can be considered a pivotal issue for modern organic chemistry. Here, we report the method for copper-catalyzed <i>N</i>-arylation of diverse oxadiazolones by diaryliodonium salts in mild conditions in high yields (up to 92%) using available CuI as a catalyst. The developed method allows to efficiently utilize both symmetric and unsymmetric diaryliodonium salts bearing auxiliary groups such as 2,4,6-trimethoxyphenyl (TMP). The evaluation of steric effects in aryl moieties to the chemoselectivity of <i>N</i>- and <i>O</i>-arylation of the 1,2,4-oxadiazol-5(4<i>H</i>)-ones exhibited the high potential of mesityl-substituted diaryliodonium salts as a selective arylation reagent. The structural study suggests that steric accessibility of <i>N</i>-atom in 1,2,4-oxadiazol-5(4<i>H</i>)-ones impact to arylation with sterically hindered diaryliodonium salts. The synthetic application of proposed method was also demonstrated on selective arylation of 1,3,4-oxadiazol-2(3<i>H</i>)-ones and 1,2,4-oxadiazole-5-thiol.

Aryl Radical Formation by Copper(I) Photocatalyzed Reduction of Diaryliodonium Salts: NMR Evidence for a CuII/CuIMechanism

2013 ◽  
Vol 19 (33) ◽  
pp. 10809-10813 ◽  
Author(s):  
Alexandre Baralle ◽  
Louis Fensterbank ◽  
Jean-Philippe Goddard ◽  
Cyril Ollivier
Keyword(s):  
Radical Formation ◽  
Aryl Radical ◽  
Diaryliodonium Salts

scholarly journals Copper-Catalyzed Selective Arylation of Oxadiazolones by Diaryliodonium Salts

2021 ◽  
Author(s):  
Natalia Soldatova ◽  
Artem Semenov ◽  
Kirill Geyl ◽  
Sergey Baykov ◽  
Anton Shetnev ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Structural Study ◽  
High Potential ◽  
Steric Effects ◽  
Mild Conditions ◽  
Diaryliodonium Salts ◽  
Steric Accessibility ◽  
Sterically Hindered ◽  
High Yields ◽  
Synthetic Application

The direct N-arylation of cyclic amides can be considered a pivotal issue for modern organic chemistry. Here, we report the method for copper-catalyzed <i>N</i>-arylation of diverse oxadiazolones by diaryliodonium salts in mild conditions in high yields (up to 92%) using available CuI as a catalyst. The developed method allows to efficiently utilize both symmetric and unsymmetric diaryliodonium salts bearing auxiliary groups such as 2,4,6-trimethoxyphenyl (TMP). The evaluation of steric effects in aryl moieties to the chemoselectivity of <i>N</i>- and <i>O</i>-arylation of the 1,2,4-oxadiazol-5(4<i>H</i>)-ones exhibited the high potential of mesityl-substituted diaryliodonium salts as a selective arylation reagent. The structural study suggests that steric accessibility of <i>N</i>-atom in 1,2,4-oxadiazol-5(4<i>H</i>)-ones impact to arylation with sterically hindered diaryliodonium salts. The synthetic application of proposed method was also demonstrated on selective arylation of 1,3,4-oxadiazol-2(3<i>H</i>)-ones and 1,2,4-oxadiazole-5-thiol.

Carbon Monoxide Related Reductions

INEOS OPEN ◽  
2020 ◽  
Vol 3 ◽  
Author(s):  
O. I. Afanasyev ◽  
◽  
D. Chusov ◽  
Keyword(s):  
Organic Chemistry ◽  
Carbon Monoxide ◽  
Reducing Agent ◽  
Current Development ◽  
Efficient Route ◽  
Development Prospects

Carbon monoxide is a unique reducing agent that is only gaining popularity in organic chemistry. This review highlights the main approaches to the application of CO as a reducing agent, summarizes and critically analyzes the key trends in this field, and describes the current development prospects. Potentially the most selective and efficient route for the realization of these processes is demonstrated.

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