Triarylamines as catalytic donors in light-mediated electron donor–acceptor complexes

Chemical Science, Journal Year: 2023, Volume and Issue: 14(13), P. 3470 - 3481

Published: Jan. 1, 2023

Recently, photochemistry of Electron Donor-Acceptor (EDA) complexes employing catalytic amounts electron donors have become interest as a new methodology in the catalysis field, allowing for decoupling transfer (ET) from bond-forming event. However, examples practical EDA systems regime remain scarce, and their mechanism is not yet well-understood. Herein, we report discovery an complex between triarylamines α-perfluorosulfonylpropiophenone reagents, catalyzing C-H perfluoroalkylation arenes heteroarenes under visible light irradiation pH- redox-neutral conditions. We elucidate this reaction using detailed photophysical characterization complex, resulting triarylamine radical cation, its turnover

Language: Английский

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Micellar Effects and their Relevance in Photochemistry and Photocatalysis

ChemCatChem, Journal Year: 2022, Volume and Issue: 15(1)

Published: Nov. 11, 2022

Abstract The encapsulation of substrates within micellar structures gives rise to a multitude effects beyond simple solubilization in water. When incorporated photochemical reaction design media may offer possibilities control both reactivity and selectivity. Herein, we describe various important phenomena such as encapsulation, polarity differences, electrostatic interactions hydrogen bonding, discuss the resulting mechanisms by which outcomes can be greatly influenced. In this concept article, showcase selected reactions demonstrate how selectively applied design.

Language: Английский

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Effect of Confined and Micellar Media on the Photo-Fries Reaction of 4-Phenoxyphenol Esters: A Valuable Key Step Toward the Preparation of Aryloxyethyl Selenocyanates

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 10, 2025

The irradiation of a series 4-phenoxyphenol esters in sustainable micellar environment has been studied from both preparative and mechanistic viewpoints, the results were compared with those obtained cyclohexane solutions. These underwent photo-Fries rearrangement reaction, microheterogeneous media induced noticeable selectivity favor ortho-regioisomer formation yields up to 96% yield. UV-visible 1D 2D NMR (DCS, NOESY, DOSY) spectroscopies have employed determine binding constant (Kb) location within hydrophobic core spherical micelles. Furthermore, diffusion coefficient (D) hydrodynamic radius (rs) also measured. Application reaction as key step multistep sequence carried out, leading preparation (4-phenoxy)-(2-n-pentylcarbonyl)-phenoxyethyl selenocyanate (10), an interesting target molecule showing potential biological activity against Trypanosoma cruzi.

Language: Английский

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Solvent Effects on the Photoinduced [6π]-Electrocyclization Reactions of Mono-, Di-, and Trisubstituted Arylamines: Photophysical, Preparative Photochemistry, and Mechanistic Investigations

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(7), P. 4405 - 4421

Published: March 28, 2023

The substituent and solvent effects on the spectroscopic behavior photoinduced [6π]-electrocyclization reaction of substituted triphenylamine derivatives have been investigated. Direct irradiation triphenylamines bearing electron-donor substituents in different solvents has provided for first time exo/endo carbazole from modest to good yields, whereas electron-withdrawing did not provide carbazoles due formation charge transfer complexes (CTCs). A corollary experiments purports that photoreaction is favored with weak electron-acceptor groups polar solvents. lowest-frequency absorption bands triarylamines (π,π* electronic transitions) displayed bathochromic shifts as polarity increased. fluorescence emission spectra behave mirror images lowest bands, showing dependence polarity. Conversely, formyl, acetyl, nitro formed CTCs behaving chromophores Hammett correlations ΔE(0,0) energies monosubstituted amines showed a bell-shape where ρ values depended physical quenching demonstrated triplet excited state univocally photoreactive leading derivatives.

Language: Английский

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Effect of sustainable and confined media on the photoinduced [6π]‐electrocyclization reaction of diphenyl and N‐methyldiphenylamines

ChemPhotoChem, Journal Year: 2024, Volume and Issue: unknown

Published: May 22, 2024

Abstract A systematic investigation of the photoinduced [6π]‐electrocyclization reaction diphenylamine and N‐methyldiphenylamine has been carried out under steady‐state time‐resolved conditions in homogeneous (cyclohexane, acetonitrile methanol) micellar solutions (sodium dodecyl sulfate ‐SDS, cetyltrimethylammonium chloride‐CTAC polyethylene glycol monododecyl ether‐Brij P35). The photolysis such compounds both micro‐heterogeneous media afforded corresponding carbazoles almost quantitative yield oxidative conditions. Furthermore, relative rate formation photoproducts increases when moving from to solution, due environmental confined hydrophobic core as highlighted by 1D 2D NMR (NOESY DOSY) spectroscopic analyses.

Language: Английский

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Photoinduced [6π]-Electrocyclic Reaction of Mono-, Di-, and Trisubstituted Triphenylamines in Acetonitrile. A Steady-State Investigation

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 87(20), P. 13439 - 13454

Published: June 8, 2022

Direct irradiation of mono-, di-, and trisubstituted triphenylamine derivatives in acetonitrile as solvent with light 254 nm has been systematically investigated, revealing that the exo/endo carbazole were formed main photoproducts from modest to good yields for triphenylamines substituted electron-donor neutral substituents. The kinetic profiles photoreaction also recorded, consumption rate constants (k) measured. These parameters show dependence on nature substituents, linear Hammett correlations carried out showcase substituent effect. On other hand, spectroscopic behavior electron-rich analyzed, suggesting fluorescence emission spectra display a mirror image lower energy absorption bands, while those amines bearing electron-acceptor groups formation charge-transfer complexes their emissions constitute deactivation pathway photoreaction.

Language: Английский

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Preparation of Carbazoles Involving 6π‐Electrocyclization, Photoredox‐, Electrochemical‐, and Thermal Cyclization Reactions: Mechanistic Insights

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 30(8)

Published: Nov. 30, 2023

Carbazole is a heterocyclic motif that can be found in diverse array of natural and unnatural products displaying wide range biological physiological properties. Furthermore, this heterocycle part electronic materials like photoconducting polymers organic optoelectronic owing to its excellent photophysical characteristics. Consequently, the development synthetic strategies for carbazole scaffolds holds potential significance material fields. In regard, variety preparation methods has been developed exploit their efficient distinct formation new C-C C-heteroatom bonds under mild conditions enabling broad substrate diversity functional group tolerance. Therefore, review focuses on synthesis set derivatives describing methodologies involve direct irradiation, photosensitization, photoredox, electrochemical thermal cyclization reactions.

Language: Английский

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Product selectivity in the photoreaction of aryl sulfonates and mesylate of estrone derivatives in sustainable and micellar media: a steady-state investigation

New Journal of Chemistry, Journal Year: 2022, Volume and Issue: 46(32), P. 15504 - 15520

Published: Jan. 1, 2022

The photochemical reaction of sulfonate steroids in a sustainable environment was carried out successfully under steady-state conditions. Significant selectivity photoproduct formation also observed.

Language: Английский

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On the application of nanosecond laser flash photolysis to the investigation of the photoreactivity of di and triarylamines

Photochemical & Photobiological Sciences, Journal Year: 2024, Volume and Issue: 23(12), P. 2269 - 2288

Published: Dec. 1, 2024

Language: Английский

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