Visible Light-Induced Transition Metal Catalysis

Chemical Reviews, Год журнала: 2021, Номер 122(2), С. 1543 - 1625

Опубликована: Окт. 8, 2021

In recent years, visible light-induced transition metal catalysis has emerged as a new paradigm in organic photocatalysis, which led to the discovery of unprecedented transformations well improvement known reactions. this subfield complex serves double duty by harvesting photon energy and then enabling bond forming/breaking events mostly via single catalytic cycle, thus contrasting established dual photocatalysis an exogenous photosensitizer is employed. addition, approach often synergistically combines catalyst–substrate interaction with photoinduced process, feature that uncommon conventional photoredox chemistry. This Review describes early development advances emerging field.

Язык: Английский

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Visible‐Light‐Induced Homolysis of Earth‐Abundant Metal‐Substrate Complexes: A Complementary Activation Strategy in Photoredox Catalysis

Angewandte Chemie International Edition, Год журнала: 2021, Номер 60(39), С. 21100 - 21115

Опубликована: Фев. 18, 2021

Abstract The mainstream applications of visible‐light photoredox catalysis predominately involve outer‐sphere single‐electron transfer (SET) or energy (EnT) processes precious metal Ru II Ir III complexes organic dyes with low photostability. Earth‐abundant metal‐based M n L ‐type (M=metal, =polydentate ligands) are rapidly evolving as alternative photocatalysts they offer not only economic and ecological advantages but also access to the complementary inner‐sphere mechanistic modes, thereby transcending their inherent limitations ultrashort excited‐state lifetimes for use effective photocatalysts. generic process, termed visible‐light‐induced homolysis (VLIH), entails formation suitable light‐absorbing ligated metal–substrate (M ‐Z; Z=substrate) that can undergo homolytic cleavage generate n−1 Z . further transformations.

Язык: Английский

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Ligand‐to‐Metal Charge Transfer (LMCT) Photochemistry at 3d‐Metal Complexes: An Emerging Tool for Sustainable Organic Synthesis

ChemCatChem, Год журнала: 2022, Номер 14(19)

Опубликована: Авг. 11, 2022

Abstract Despite the rich photochemistry of 3d‐metal complexes, utilization excited‐state reactivity these compounds in organic synthesis has been historically overlooked. The advent photoredox catalysis changed perception synthetic chemists towards photochemistry, and nowadays potential photoinduced, outer‐sphere single‐electron transfer events is widely recognized. More recently, an emerging new mode photoactivation taken spotlight, based on inner‐sphere triggered by population ligand‐to‐metal charge‐transfer (LMCT) excited states. Contrarily to photoredox, LMCT‐activation does not rely matching redox potentials, offers unique profiles particularly well suited Earth‐abundant metal complexes. Those appealing features are propelling development methods using this blueprint generate highly reactive open‐shell species under mild conditions. aim contribution provide a didactical tool for comprehension concept facilitate methodologies achieve sustainable chemical transformations.

Язык: Английский

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Direct decarboxylative Giese reactions

Chemical Society Reviews, Год журнала: 2022, Номер 51(4), С. 1415 - 1453

Опубликована: Янв. 1, 2022

This review summarizes recent progress on using carboxylic acids directly as convenient precursors for the 1,4-radical conjugate addition (Giese) reaction.

Язык: Английский

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Recent developments in the difunctionalization of alkenes with C–N bond formation

Organic Chemistry Frontiers, Год журнала: 2021, Номер 8(18), С. 5206 - 5228

Опубликована: Янв. 1, 2021

Various alkene difunctionalization reactions involving nitridization, diamination, azidation, oxyamination, carboamination, aminohalogenation, and nitration are introduced in this review.

Язык: Английский

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Iron Photoredox Catalysis–Past, Present, and Future

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(17), С. 9369 - 9388

Опубликована: Апрель 20, 2023

Photoredox catalysis of organic reactions driven by iron has attracted substantial attention throughout recent years, due to potential environmental and economic benefits. In this Perspective, three major strategies were identified that have been employed date achieve reactivities comparable the successful noble metal photoredox catalysis: (1) Direct replacement a center in archetypal polypyridyl complexes, resulting metal-centered photofunctional state. (2) situ generation photoactive complexes substrate coordination where are via intramolecular electron transfer involving charge-transfer states, for example, through visible-light-induced homolysis. (3) Improving excited-state lifetimes redox potentials states new ligand design. We seek give an overview evaluation developments rapidly growing field and, at same time, provide outlook on future iron-based catalysis.

Язык: Английский

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Iron-Catalyzed C(Sp³)–H Borylation, Thiolation, and Sulfinylation Enabled by Photoinduced Ligand-to-Metal Charge Transfer

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(13), С. 7600 - 7611

Опубликована: Март 23, 2023

Catalytic C(sp3)-H functionalization has provided enormous opportunities to construct organic molecules, facilitating the derivatization of complex pharmaceutical compounds. Within this framework, direct hydrogen atom transfer (HAT) photocatalysis becomes an appealing approach goal. However, viable substrates utilized in these protocols are limited, and site selectivity shows preference activated thermodynamically favored bonds. Herein, we describe development undirected iron-catalyzed borylation, thiolation, sulfinylation reactions enabled by photoinduced ligand-to-metal charge (LMCT) process. These exhibit remarkably broad substrate scope (>150 examples total), most importantly, all three show unconventional regioselectivity, with occurrence preferentially at distal methyl position. The procedures operationally simple readily scalable provide access high-value products from hydrocarbons one step. Mechanistic studies control experiments indicate that afforded is not only relevant HAT species but also largely affected use boron- sulfone-based radical acceptors.

Язык: Английский

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A Unified Approach to Decarboxylative Halogenation of (Hetero)aryl Carboxylic Acids

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(18), С. 8296 - 8305

Опубликована: Апрель 29, 2022

Aryl halides are a fundamental motif in synthetic chemistry, playing critical role metal-mediated cross-coupling reactions and serving as important scaffolds drug discovery. Although thermal decarboxylative functionalization of aryl carboxylic acids has been extensively explored, the scope existing halodecarboxylation methods remains limited, there currently exists no unified strategy that provides access to any type halide from an acid precursor. Herein, we report general catalytic method for direct halogenation (hetero)aryl via ligand-to-metal charge transfer. This accommodates exceptionally broad substrates. We leverage radical intermediate toward divergent pathways: (1) atom transfer bromo- or iodo(hetero)arenes (2) capture by copper subsequent reductive elimination generate chloro- fluoro(hetero)arenes. The proposed mechanism is supported through array spectroscopic studies.

Язык: Английский

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Copper-photocatalyzed ATRA reactions: concepts, applications, and opportunities

Chemical Society Reviews, Год журнала: 2022, Номер 51(13), С. 5287 - 5299

Опубликована: Янв. 1, 2022

This review summarizes the different applications and underlying concepts that are applied for Cu( i )- or ii )-photocatalyzed difunctionalizations of alkenes.

Язык: Английский

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Elucidating the Mechanism of Excited-State Bond Homolysis in Nickel–Bipyridine Photoredox Catalysts

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(14), С. 6516 - 6531

Опубликована: Март 30, 2022

Ni 2,2'-bipyridine (bpy) complexes are commonly employed photoredox catalysts of bond-forming reactions in organic chemistry. However, the mechanisms by which they operate still under investigation. One potential mode catalysis is via entry into Ni(I)/Ni(III) cycles, can be made possible light-induced, excited-state Ni(II)-C bond homolysis. Here, we report experimental and computational analyses a library Ni(II)-bpy aryl halide complexes, Ni(Rbpy)(R'Ph)Cl (R = MeO, t-Bu, H, MeOOC; R' CH3, OMe, F, CF3), to illuminate mechanism At given excitation wavelengths, photochemical homolysis rate constants span 2 orders magnitude across these structures correlate linearly with Hammett parameters both bpy ligands, reflecting structural control over key metal-to-ligand charge-transfer (MLCT) ligand-to-metal (LMCT) energy surfaces (PESs). Temperature- wavelength-dependent investigations reveal moderate barriers (ΔH‡ ∼ 4 kcal mol-1) minimum threshold (∼55 mol-1, 525 nm), respectively. Correlations electronic structure calculations further support repulsive triplet PESs featuring critical aryl-to-Ni LMCT lead rupture. Structural provides rational approach utilize photonic leverage processes synthetic

Язык: Английский

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