Light‐Mediated Seleno‐Functionalization of Organic Molecules: Recent Advances

The Chemical Record, Journal Year: 2021, Volume and Issue: 21(10), P. 2739 - 2761

Published: March 3, 2021

Organoselenium compounds constitute an important class of substances with applications in the biological, medicinal and material sciences as well modern organic synthesis, attracting considerable attention from scientific community. Therefore, construction C-Se bond via facile, efficient sustainable strategies to access complex scaffolds simple substrates are appealing hot topic. Visible light can be regarded alternative source energy is associated environmentally-friendly processes. Recently, use visible-light mediated seleno-functionalization has emerged ideal powerful route obtain high-value selenylated products, diminished cost waste. This approach, involving photo-excited substrates/catalyst single-electron transfer (SET) between presence visible been successfully used versatile direct insertion organoselenium moieties activated unactivated C(sp3 )-H, C(sp2 C(sp)-H bonds C-heteroatom bonds. In most cases, ease operation accessibility (LEDs or commercial CFL bulbs) makes this approach more attractive than traditional strategies.

Language: Английский

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“Green Is the Color”: An Update on Ecofriendly Aspects of Organoselenium Chemistry

Molecules, Journal Year: 2022, Volume and Issue: 27(5), P. 1597 - 1597

Published: Feb. 28, 2022

Organoselenium compounds have been successfully applied in biological, medicinal and material sciences, as well a powerful tool for modern organic synthesis, attracting the attention of scientific community. This great success is mainly due to breaking paradigm demonstrated by innumerous works, that selenium were toxic would potential impact on environment. In this update review, we highlight relevance these several fields research possibility synthesize them through more environmentally sustainable methodologies, involving catalytic processes, flow chemistry, electrosynthesis, use alternative energy sources, including mechanochemical, photochemistry, sonochemical microwave irradiation.

Language: Английский

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Regio- and stereoselective electrochemical selenoalkylation of alkynes with 1,3-dicarbonyl compounds and diselenides

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(10), P. 2815 - 2820

Published: Jan. 1, 2022

A regio- and stereoselective electrochemical approach for the selenoalkylation of alkynes with 1,3-dicarbonyl compounds diselenides has been developed.

Language: Английский

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Visible Light-Mediated C(sp²)–H Selenylation of Amino Pyrazole and Amino Uracils in the Presence of Rose Bengal as an Organophotocatalyst

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 87(2), P. 1230 - 1239

Published: Jan. 7, 2022

Herein, we report an efficient methodology for the synthesis of alkyl, benzyl, and phenyl selenoethers aminopyrazoles aminouracils by C(sp2)-H functionalization in presence visible light Rose Bengal as organophotocatalyst. The reaction amino pyrazole/iosothiazole/isoxazole or uracils with 0.5 equivalent diphenyl/dibenzyl/diethyl diselenides acetonitrile medium a catalytic amount provided corresponding phenyl, ethyl good to very yields. We have also utilized some selenylated preparation pyrazole-fused dihydropyrimidines tethered arylselenoethers catalyst-free one-pot three-component reaction. notable features this are metal-free conditions, yields, use organic photocatalyst, wide substrate scope; it is applicable gram-scale provides medicinally important heterocycles such amio-pyrazole, isoxazole, isothiazole, uracils.

Language: Английский

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Blue Light Irradiated Metal-, Oxidant-, and Base-Free Cross-Dehydrogenative Coupling of C(sp²)–H and N–H Bonds: Amination of Naphthoquinones with Amines

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(11), P. 7401 - 7424

Published: May 12, 2023

Herein, we report a blue-light-driven amination of C(sp2)-H bond naphthoquinones and quinones with the N-H primary secondary amines for synthesis 2-amino-naphthoquinones 2-amino-quinones. The coupling wide array aliphatic, aromatic, chiral, primary, having electron donating (-CH3, -OCH3, -SCH3), withdrawing (-F, -Cl, -Br, -I), CO2H, -OH, -NH2 groups acidic protons selectively occurred to afford C-N coupled in 60-99% yields hydrogen gas as byproduct methanol solvent without using any additional reagents, additives, oxidant under blue light irradiation. Mechanistic insight by DFT computation, controlled experiments, kinetic isotopic effect, substitution effect substrates suggest that reaction proceeds radical pathway which naphthoquinone forms highly oxidizing naphthoquinonyl biradical upon irradiation (457 nm). Consequently, transfer from electron-rich amine an leads anion aminyl cation, followed proton delocalization leading carbon-centered radical. cross-coupling nitrogen radicals bond, subsequent elimination (which was also confirmed GC-TCD), affording 2-amino-1,4-naphthoquinone metal-, reagent-, base-, oxidant-free conditions.

Language: Английский

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Photo- or Electrochemical Cyclization of Dienes with Diselenides to Access Seleno-Benzo[b]azepines

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(11), P. 7245 - 7255

Published: May 23, 2023

A cascade selenylation/cyclization of dienes with diselenides has been realized under visible-light irradiation or electrolysis conditions. Employing O2 electricity as a "green" oxidant, this protocol provides green and efficient method for an array biologically important seleno-benzo[b]azepine derivatives in moderate to good yields. The direct sunlight gram-scale reaction render the approach practical attractive.

Language: Английский

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Visible-light induced selenocyclization of 2-ethynylanilines under ambient conditions: simple FeBr3 as a dual-functional catalyst

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(30), P. 6198 - 6204

Published: Jan. 1, 2024

Reported herein is a visible-light induced selenocyclization of 2-ethynylanilines under ambient conditions, with simple FeBr 3 as dual-functional catalyst.

Language: Английский

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Visible-Light-Induced, Catalyst-Free Radical Cross-Coupling Cyclization of N-Allylbromodifluoroacetamides with Disulfides or Diselenides

The Journal of Organic Chemistry, Journal Year: 2020, Volume and Issue: 85(8), P. 5670 - 5682

Published: April 2, 2020

A visible-light-induced, catalyst-free radical cross-coupling cyclization of diselenides or disulfides with N-allylbromodifluoroacetamide has been developed. This developed protocol exhibits good functional group tolerance and affords a variety 4-thio- 4-seleno-substituted 3,3-difluoro-γ-lactams in moderate to yields. Based on control experiments, plausible radical-radical pathway is proposed.

Language: Английский

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Synthetic strategies for aryl/heterocyclic selenides and tellurides under transition-metal-catalyst free conditions

RSC Advances, Journal Year: 2021, Volume and Issue: 11(12), P. 6682 - 6698

Published: Jan. 1, 2021

Aryl and heteroaryl selenides tellurides are found to have broad applications in the diverse fields such as medicine, biology, materials science, pharmaceutical etc. thus their synthesis remains a challenging field for synthetic chemists last decade. Although large no of methodologies been developed based on metal catalyzed C-Se/Te coupling, number researches has focused developing catalyst free protocols due sustainability recent times. This review covers all developments decade under conditions by using different sustainable techniques e.g. greener reagents solvents, ball milling, visible light photocatalysis, microwave, ultrasound

Language: Английский

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Tetravalent Spiroselenurane Catalysts: Intramolecular Se···N Chalcogen Bond-Driven Catalytic Disproportionation of H₂O₂ to H₂O and O₂ and Activation of I₂ and NBS

Inorganic Chemistry, Journal Year: 2022, Volume and Issue: 61(23), P. 8729 - 8745

Published: May 31, 2022

Chalcogen-bonding interactions have recently gained considerable attention in the field of synthetic chemistry, structure, and bonding. Here, three organo-spiroselenuranes, having a Se(IV) center with strong intramolecular Se···N chalcogen-bonded interaction, been isolated by oxidation respective bis(2-benzamide) selenides derived from an 8-aminoquinoline ligand. Further, synthesized spiroselenuranes, when assayed for their antioxidant activity, show disproportionation hydrogen peroxide into H2O O2 first-order kinetics respect to H2O2 first time any organoselenium molecules as monitored 1H NMR spectroscopy. Electron-donating 5-methylthio-benzamide ring-substituted spiroselenurane disproportionates at high rate 15.6 ± 0.4 × 103 μM min-1 constant 8.57 0.50 10-3 s-1, whereas 5-methoxy unsubstituted-benzamide spiroselenuranes catalyzed rates 7.9 0.3 2.9 constants 1.16 0.02 0.325 0.025 respectively. The evolved oxygen gas spiroselenurane-catalyzed disproportion has also confirmed chromatograph-thermal conductivity detector (GCTCD) portable digital polarographic dissolved probe. Additionally, exhibit thiol peroxidase activities reduction benzenethiol co-reductant UV-visible Next, bonded explored catalysts iodolactonization bromination arenes. activated I2 toward alkenoic acids under base-free conditions. Similarly, efficient chemo- regioselective monobromination various arenes NBS achieved. Mechanistic insight reactions 77Se NMR, mass spectrometry, spectroscopy, single-crystal X-ray theoretical (DFT, NBO, AIM) studies. It seems that highly electrophilic nature selenium is attributed presence interaction vacant coordination site crucial activation H2O2, I2, NBS. reaction tetravalent would lead octahedral-Se(VI) intermediate, which reduced back due thermodynamic instability its highest state N-donor atom.

Language: Английский

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