Triangulenium Ions: Versatile Organic Photoredox Catalysts for Green-Light-Mediated Reactions DOI
Thomas L. Gianetti, Marko H. Nowack, Jules Moutet

et al.

Synlett, Journal Year: 2023, Volume and Issue: 35(03), P. 307 - 312

Published: June 26, 2023

Abstract The development of tunable organic photoredox catalysts remains important in the field catalysis. A highly modular and family trianguleniums (azadioxatriangulenium, diazaoxatriangulenium, triazatriangulenium), related [4]helicene quinacridinium have been used as for photoreductions photooxidations under visible light irradiation (λ = 518–640 nm). highlight this is their readily redox properties, leading to different reactivities. We report use photocatalysts aerobic oxidative hydroxylation arylboronic acids cross-dehydrogenative coupling reaction N-phenyl-1,2,3,5-tetrahydroisoquinoline with nitromethane through reductive quenching. Furthermore, potential photoreduction has demonstrated catalysis an intermolecular atom-transfer radical addition via These transformations serve benchmarks that easily synthesized trianguleniums, congeners acridiniums, are versatile applications both photoreductions.

Language: Английский

Red Light-Based Dual Photoredox Strategy Resembling the Z-Scheme of Natural Photosynthesis DOI Creative Commons
Felix Glaser, Oliver S. Wenger

JACS Au, Journal Year: 2022, Volume and Issue: 2(6), P. 1488 - 1503

Published: June 10, 2022

Photoredox catalysis typically relies on the use of single chromophores, whereas strategies, in which two different light absorbers are combined, rare. In photosystems I and II green plants, separate chromophores P680 P700 both absorb independently one another, then their excitation energy is combined so-called Z-scheme, to drive an overall reaction that thermodynamically very demanding. Here, we adapt this concept perform photoredox reactions organic substrates with input red photons instead blue or UV light. Specifically, a CuI bis(α-diimine) complex combination situ formed 9,10-dicyanoanthracenyl radical anion presence excess diisopropylethylamine catalyzes ca. 50 dehalogenation detosylation reactions. This dual approach seems useful because less damaging has greater penetration depth than radiation. UV-vis transient absorption spectroscopy reveals subtle change solvent from acetonitrile acetone induces changeover mechanism, involving either dominant photoinduced electron transfer triplet-triplet pathway. Our study illustrates mechanistic complexity systems operating under multiphotonic conditions, it provides insights into how competition between desirable unwanted steps can become more controllable.

Language: Английский

Citations

75
Red-Light-Active N,C,N-Pincer Bismuthinidene: Excited State Dynamics and Mechanism of Oxidative Addition into Aryl Iodides DOI Creative Commons
Alexios Stamoulis, Mauro Mato, Paolo Cleto Bruzzese

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 10, 2025

Despite the progress made in field of synthetic organic photocatalysis over past decade, use higher wavelengths, especially those deep-red portion electromagnetic spectrum, remains comparatively rare. We have previously disclosed that a well-defined N,C,N-pincer bismuthinidene (1a) can undergo formal oxidative addition into wide range aryl electrophiles upon absorption low-energy red light. In this study, we map out photophysical dynamics 1a and glean insights nature excited state responsible for activation electrophiles. Transient emission techniques reveal that, irradiation with light, complex undergoes direct S0 → S1 metal-to-ligand charge transfer (MLCT) transition, followed by rapid intersystem crossing (ISC) to highly reducing emissive triplet (−2.61 V vs Fc+/0 MeCN). The low dissipative losses incurred during ISC (∼6% incident light energy) help rationalize ability convert useful chemical energy. Spectroelectrochemical computational data support charge-separated excited-state structure radical-anion character on ligand radical-cation bismuth. Kinetic studies competition experiments afford mechanism iodides; concerted inner-sphere processes from are ruled out, strongly supporting pathway proceeds via outer-sphere dissociative electron transfer.

Language: Английский

Citations

3
Diastereoselective and enantioselective photoredox pinacol coupling promoted by titanium complexes with a red-absorbing organic dye DOI Creative Commons
Francesco Calogero, Giandomenico Magagnano, Simone Potenti

et al.

Chemical Science, Journal Year: 2022, Volume and Issue: 13(20), P. 5973 - 5981

Published: Jan. 1, 2022

The pinacol coupling reaction, a reductive of carbonyl compounds that proceeds through the formation ketyl radicals in presence an electron donor, affords corresponding 1,2-diols one single step. photoredox version this transformation has been accomplished using different organic dyes or photoactive metal complexes sacrificial donors such as tertiary amines Hantzsch's ester. Normally, homo-coupling reactive is neither diastereo- nor enantio-selective. Herein, we report highly diastereoselective reaction aromatic aldehydes promoted by 5 mol% non-toxic, inexpensive and available Cp2TiCl2 complex. key feature allows complete control diastereoselectivity employment red-absorbing dye redox-active titanium Taking advantage well-tailored potential dye, selective reduction Ti(iv) to Ti(iii) achieved. These conditions enable d,l (syn) diastereoisomer favored product (d.r. > 20 : 1 most cases). Moreover, employing simply prepared chiral SalenTi complex, new gave diastereoselection for diastereoisomer, high enantiocontrol (up 92% enantiomeric excess).

Language: Английский

Citations

41
Evolution and Future of Hetero‐ and Hydro‐Trifluoromethylations of Unsaturated C−C Bonds DOI
Shintaro Kawamura, Pablo Barrio, Santos Fustero

et al.

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(4), P. 398 - 462

Published: Jan. 18, 2023

Abstract The difunctionalizative trifluoromethylation of unsaturated C−C bonds is a highly useful and efficient method for the synthesis trifluoromethyl compounds with attractive architectures from simple feedstocks, allowing introduction CF 3 group along wide variety substituents either inter‐ or intramolecularly. Given that molecules are increasingly used as promising bioactive species in design new drugs agrochemicals, has been extensively studied during last decade. This review focuses on reactions proceeding via simultaneous formation C−heteroatom (O, N, S, Se, B) C−H bonds, these provide group‐containing building blocks. To identify trends prospects evolution this methodology, we systematically describe variants types more general view reaction conditions, modes, mechanisms. presented comprehensive survey enables categorization into those synthetically mature room further development. magnified image

Language: Английский

Citations

40
Applications of red light photoredox catalysis in organic synthesis DOI
Alexander Schade, Liangyong Mei

Organic & Biomolecular Chemistry, Journal Year: 2023, Volume and Issue: 21(12), P. 2472 - 2485

Published: Jan. 1, 2023

This review summarizes the current progress in red light-mediated and near-infrared-induced reactions organic synthesis.

Language: Английский

Citations

38
Low-energy photoredox catalysis DOI
David C. Cabanero, Tomislav Rovis

Nature Reviews Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 11, 2024

Language: Английский

Citations

18
Silver-Enabled Dearomative Trifluoromethoxylation of Indoles DOI
Zhijie Deng,

Lingduan Meng,

Bing Xiao

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(4), P. 2325 - 2332

Published: Jan. 17, 2024

The only known method for the dearomative trifluoromethoxylation of indoles is preliminary, with one substrate successfully undergoing reaction. In this study, we not developed a broadly applicable indole but also achieved divergent by fine-tuning reaction conditions. Under optimized conditions, silver salt and an easily handled OCF3 reagent, various smoothly underwent dearomatization to afford diverse array ditrifluoromethoxylated indolines in 50–84% isolated yields up 37:1 diastereoselectivity, fluorinated trifluoromethoxylated were obtained exclusive trans selectivity. addition, conditions compatible other heteroaromatic rings as well styrene moieties.

Language: Английский

Citations

12
Red-Light Mediated Formylation of Indoles Using Helical Carbenium Ion as Photoredox Catalyst DOI

Nand Lal,

Deepshikha Deepshikha,

P. R. SINGH

et al.

Chemical Communications, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

A red-light ( λ = 640 nm)-mediated C-3 formylation of indoles utilizing a helical carbenium ion as photocatalyst and 2,2-dimethoxy- N , -dimethylethanamine formylating source is presented.

Language: Английский

Citations

2
Electrochemical Dearomatization of Indoles: Access to Diversified Fluorine-Containing Spirocyclic Indolines DOI

Kangdong Mo,

Xiaocong Zhou,

Ju Wu

et al.

Organic Letters, Journal Year: 2022, Volume and Issue: 24(15), P. 2788 - 2792

Published: April 11, 2022

A robust and green electrochemical dearomatization of indoles was developed by merging a fluorine-containing group to an indole nucleus under oxidant-free conditions, delivering diverse array tri- difluoromethylated 3,3-spiroindolines with good functional tolerance.

Language: Английский

Citations

30
Red-Shifting Blue Light Photoredox Catalysis for Organic Synthesis: A Graphical Review DOI Creative Commons
Tomislav Rovis, Logan R. Beck,

Katherine A. Xie

et al.

SynOpen, Journal Year: 2023, Volume and Issue: 07(01), P. 76 - 87

Published: Feb. 1, 2023

Abstract Photoredox catalysis has revolutionized synthetic chemistry in recent decades. However, the field traditionally used high-energy blue/ultraviolet light to activate chromophores. High-energy irradiation is associated with several drawbacks (e.g., activation of sensitive functional groups, undesired metal-ligand homolysis, background molecules, and poor penetration), which led researchers develop alternative systems lower energy deep red (DR) or near-infrared (NIR) light. This graphical review provides a concise overview photophysical principles relevant photoredox catalysis. Several applications that benefit from low-energy irradiation, such as large-scale batch reactions, photodynamic therapy, biological labeling, multi-photon excitation are reviewed.

Language: Английский

Citations

18