Visible Light-Induced Transition Metal Catalysis

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 1543 - 1625

Published: Oct. 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.

Language: Английский

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

ChemCatChem, Journal Year: 2022, Volume and Issue: 14(19)

Published: Aug. 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.

Language: Английский

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Photoactive Copper Complexes: Properties and Applications

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(22), P. 16365 - 16609

Published: Nov. 9, 2022

Photocatalyzed and photosensitized chemical processes have seen growing interest recently become among the most active areas of research, notably due to their applications in fields such as medicine, synthesis, material science or environmental chemistry. Among all homogeneous catalytic systems reported date, photoactive copper(I) complexes been shown be especially attractive, not only alternative noble metal complexes, extensively studied utilized recently. They are at core this review article which is divided into two main sections. The first one focuses on an exhaustive comprehensive overview structural, photophysical electrochemical properties mononuclear typical examples highlighting critical structural parameters impact being presented enlighten future design complexes. second section devoted application (photoredox catalysis organic reactions polymerization, hydrogen production, photoreduction carbon dioxide dye-sensitized solar cells), illustrating progression from early current state-of-the-art showcasing how some limitations can overcome with high versatility.

Language: Английский

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Decarboxylative cross-nucleophile coupling via ligand-to-metal charge transfer photoexcitation of Cu(ii) carboxylates

Nature Chemistry, Journal Year: 2022, Volume and Issue: 14(1), P. 94 - 99

Published: Jan. 1, 2022

Language: Английский

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Scaffold hopping by net photochemical carbon deletion of azaarenes

Science, Journal Year: 2022, Volume and Issue: 376(6592), P. 527 - 532

Published: April 28, 2022

Discovery chemists routinely identify purpose-tailored molecules through an iterative structural optimization approach, but the preparation of each successive candidate in a compound series can rarely be conducted manner matching their thought process. This is because many necessary chemical transformations required to modify cores straightforward fashion are not applicable complex contexts. We report method that addresses one facet this problem by allowing hop directly between chemically distinct heteroaromatic scaffolds. Specifically, we show selective photolysis quinoline

Language: Английский

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Carboxylic Acids as Adaptive Functional Groups in Metallaphotoredox Catalysis

Accounts of Chemical Research, Journal Year: 2022, Volume and Issue: 55(23), P. 3481 - 3494

Published: Nov. 22, 2022

The development of palladium-catalyzed cross-coupling methods for the activation C(sp2)-Br bonds facilitated access to arene-rich molecules, enabling a concomitant increase in prevalence this structural motif drug molecules recent decades. Today, there is growing appreciation value incorporating saturated C(sp3)-rich scaffolds into pharmaceutically active as means achieve improved solubility and physiological stability, providing impetus develop new coupling strategies these challenging motifs most straightforward way possible. As an alternative classical two-electron chemistry, redox chemistry can enable elusive transformations, recently, by interfacing abundant first-row transition-metal catalysis with photoredox catalysis. such, functionalization ubiquitous versatile functional handles such (aliphatic) carboxylic acids via metallaphotoredox has emerged valuable field research over past eight years.In Account, we will outline progress methodologies that employ aliphatic (hetero)aromatic adaptive groups. Whereas decarboxylative often necessitate preactivated form redox-active esters or ligands hypervalent iodine reagents, direct use native acid functionality are highly desired have been accomplished through protocols. found bench-stable undergo diverse alkylation, arylation, amination, trifluoromethylation, leveraging prevalent transition metals nickel copper. Likewise, aryl now able halogenation borylation, entry points traditional, primarily palladium- copper-catalyzed strategies. Given breadth group tolerance employed reaction conditions, late-stage toward targets become standard tool design, synthesis various diversified molecules. rapid rise positively inspired pharmaceutical discovery be further accelerated novel development. achievement generality optimization campaigns allows future breakthroughs render protocols more reliable applicable industry. This article intended highlight, particular, (i) employment (hetero)aryl powerful (ii) need still-elusive selective transformations.We strongly believe functionalities inspire researchers across world investigate complex molecular targets.

Language: Английский

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

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(18), P. 8296 - 8305

Published: April 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.

Language: Английский

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Decarboxylative Borylation and Cross-Coupling of (Hetero)aryl Acids Enabled by Copper Charge Transfer Catalysis

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(14), P. 6163 - 6172

Published: April 4, 2022

We report a copper-catalyzed strategy for arylboronic ester synthesis that exploits photoinduced ligand-to-metal charge transfer (LMCT) to convert (hetero)aryl acids into aryl radicals amenable ambient-temperature borylation. This near-UV process occurs under mild conditions, requires no prefunctionalization of the native acid, and operates broadly across diverse aryl, heteroaryl, pharmaceutical substrates. also one-pot procedure decarboxylative cross-coupling merges catalytic LMCT borylation palladium-catalyzed Suzuki-Miyaura arylation, vinylation, or alkylation with organobromides access range value-added products. The utility these protocols is highlighted through development heteroselective double-decarboxylative C(sp2)-C(sp2) coupling sequence, pairing halogenation processes two distinct (including substrates) subsequent cross-coupling.

Language: Английский

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Photocatalytic hydrofluoroalkylation of alkenes with carboxylic acids

Nature Chemistry, Journal Year: 2023, Volume and Issue: 15(12), P. 1683 - 1692

Published: Nov. 13, 2023

Language: Английский

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Identification of Alkoxy Radicals as Hydrogen Atom Transfer Agents in Ce-Catalyzed C–H Functionalization

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 145(1), P. 359 - 376

Published: Dec. 20, 2022

The intermediacy of alkoxy radicals in cerium-catalyzed C–H functionalization via H-atom abstraction has been unambiguously confirmed. Catalytically relevant Ce(IV)–alkoxide complexes have synthesized and characterized by X-ray diffraction. Operando electron paramagnetic resonance transient absorption spectroscopy experiments on isolated pentachloro Ce(IV) alkoxides identified as the sole heteroatom-centered radical species generated ligand-to-metal charge transfer (LMCT) excitation. Alkoxy-radical-mediated hydrogen atom (HAT) verified kinetic analysis, density functional theory (DFT) calculations, reactions under strictly chloride-free conditions. These experimental findings establish critical role Ce-LMCT catalysis definitively preclude involvement chlorine radical. This study also reinforced necessity a high relative ratio alcohol vs Ce for selective alkoxy-radical-mediated HAT, seemingly trivial changes can lead to drastically different mechanistic pathways. Importantly, previously proposed radical–alcohol complex, postulated explain alkoxy-radical-enabled selectivities this system, examined scrutiny ruled out regioselectivity studies, experiments, high-level calculations. Moreover, peculiar selectivity generation LMCT homolysis heteroleptic analyzed back-electron (BET) may regulated efficiency formation ligand-centered radicals.

Language: Английский

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