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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C–H functionalization reactions enabled by hydrogen atom transfer to carbon-centered radicals

Chemical Science, Journal Year: 2020, Volume and Issue: 11(48), P. 12974 - 12993

Published: Jan. 1, 2020

Intramolecular and intermolecular HAT to C-centered radicals enables selective C–H functionalization of organic molecules.

Language: Английский

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Enantioselective Radical Reactions Using Chiral Catalysts

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(6), P. 5842 - 5976

Published: Jan. 24, 2022

Benefiting from the impressive increase in fundamental knowledge, last 20 years have shown a continuous burst of new ideas and consequently plethora catalytic methods for enantioselective radical reactions. This review aims to provide complete survey progress achieved over this latter period. The first part focuses on use chiral organocatalysts, these include catalysts covalently linked substrate those that interact with by weaker interactions like hydrogen bonds. second is devoted transition-metal redox catalysis which organized according increasing atomic number first-row transition metals (Ti, Cr, Fe, Mn, Co, Ni, Cu). Bioinspired manganese- iron-mediated hydroxylations oxidations are also discussed. A specific section dedicated reactivity Ru, Rh, Ir complexes as Lewis acids special focus at metal. Absorption photons result different events such energy transfer, single-electron hydrogen-atom transfer facilitating formation radicals. Organocatalysis has been successfully combined photocatalysts, opened pathways enlarging precursors available. merger photocatalysis organo- or metalla-photocatalysis brought novelty allowed discovery large original transformations. enzyme-catalyzed reactions involving intermediates largely benefit visible-light irradiation included review. provides comprehensive inventory goal detailing reaction mechanisms involved transformations any nonspecialist could find their own creativity invent yet unknown applications.

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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Visible-Light-Driven Catalytic Reductive Carboxylation with CO₂

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(19), P. 10871 - 10885

Published: Aug. 28, 2020

Carbon dioxide (CO2) is an important C1 source for the generation of carboxylic acids and derivatives. Stoichiometric catalytic carboxylation nucleophiles, including organometallic reagents, with CO2 has been widely investigated. Since many kinds reagents are prepared from electrophiles, transition-metal-catalyzed direct diverse electrophiles attracted much attention high step economy user-friendly protocols. Although significant progress achieved, use stoichiometric metallic or pyrophoric reductants common. The renaissance photochemistry seen numerous efforts devoted to light-driven CO2, which become one most active directions in this field. In Perspective, we summarize recent advances visible-light-driven reductive substrates, such as unsaturated hydrocarbons, organic (pseudo)halides, imines, presence mild electron donors, amines, Hantzsch esters, formates. We highlight mechanisms reactions, can proceed absence a photoredox catalyst dual visible light photoredox/transition metal system. also discuss future field offer some insight into challenges that remain.

Language: Английский

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POM-incorporated ZnIn2S4 Z-scheme dual-functional photocatalysts for cooperative benzyl alcohol oxidation and H2 evolution in aqueous solution

Applied Catalysis B Environment and Energy, Journal Year: 2022, Volume and Issue: 306, P. 121087 - 121087

Published: Jan. 7, 2022

Language: Английский

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Nickel and Palladium Catalysis: Stronger Demand than Ever

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(2), P. 1180 - 1200

Published: Jan. 5, 2022

Key similarities and differences of Pd Ni in catalytic systems are discussed. Overall, catalyze a vast number similar C–C C–heteroatom bond-forming reactions. However, the smaller atomic radius lower electronegativity Ni, as well more negative redox potentials low-valent species, often provide higher reactivity oxidative addition or insertion reactions persistence alkyl-Ni intermediates against β-hydrogen elimination, thus enabling activation reluctant electrophiles, including alkyl electrophiles. Another key point relates to stability open-shell electronic configurations Ni(I) Ni(III) compared with Pd(I) Pd(III). Nickel very involve interconvertible Ni(n+) active species variable oxidation states (Ni(0), Ni(I), Ni(II), Ni(III)). In contrast, involving Pd(III) still relatively less developed may require facilitation by special ligands merging photo- electrocatalysis. high Pd(n+) ensure their facile reduction Pd(0) under assistance numerous reagents solvents, providing concentrations molecular Pd1(0) complexes that can reversibly aggregate into Pdn clusters nanoparticles form cocktail Pdn(0) various nuclearities (i.e., values "n"). Ni(0) strong reductants; they sensitive deactivation air other oxidizers and, consequence, operate at catalyst loadings than palladium same The ease robustness versatility for catalysis, whereas variety enables diverse uncommon reactivity, albeit requiring efforts stabilization nickel systems. As discussion, we note easily "cocktail particles" different but (Pd1, Pdn, NPs), behave species" is stable nuclearities. Undoubtedly, there stronger demand ever not only develop improved efficient catalysts also understand mechanisms

Language: Английский

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Direct Enantioselective C(sp³)–H Acylation for the Synthesis of α-Amino Ketones

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(45), P. 19058 - 19064

Published: Oct. 30, 2020

A direct enantioselective acylation of α-amino C(sp3)-H bonds with carboxylic acids has been achieved via the merger transition metal and photoredox catalysis. This straightforward protocol enables cross-coupling a wide range acids, one class feedstock chemicals, readily available N-alkyl benzamides to produce highly valuable ketones in high enantioselectivities under mild conditions. The synthetic utility this method is further demonstrated by gram scale synthesis application late-stage functionalization. provides an unprecedented solution address challenging stereocontrol metallaphotoredox catalysis Mechanistic studies suggest α-C(sp3)-H bond benzamide coupling partner cleavage photocatalytically generated bromine radicals form alkyl radicals, which subsequently engages nickel-catalyzed asymmetric acylation.

Language: Английский

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Visible light-induced recyclable g-C₃N₄ catalyzed thiocyanation of C(sp²)–H bonds in sustainable solvents

Green Chemistry, Journal Year: 2021, Volume and Issue: 23(10), P. 3677 - 3682

Published: Jan. 1, 2021

A metal-free photocatalytic strategy for the preparation of thiocyanated heterocycles from inexpensive NH₄SCN has been developed using carbon nitride (g-C₃N₄) as a general heterogeneous catalyst.

Language: Английский

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Iron Photoredox Catalysis–Past, Present, and Future

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(17), P. 9369 - 9388

Published: April 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.

Language: Английский

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