Photoredox-Catalyzed C–H Functionalization Reactions

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 1925 - 2016

Published: Sept. 29, 2021

The fields of C–H functionalization and photoredox catalysis have garnered enormous interest utility in the past several decades. Many different scientific disciplines relied on strategies including natural product synthesis, drug discovery, radiolabeling, bioconjugation, materials, fine chemical synthesis. In this Review, we highlight use reactions. We separate review into inorganic/organometallic catalysts organic-based catalytic systems. Further subdivision by reaction class─either sp2 or sp3 functionalization─lends perspective tactical for these methods synthetic applications.

Language: Английский

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Enantioselective Photochemical Reactions Enabled by Triplet Energy Transfer

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 1626 - 1653

Published: July 6, 2021

For molecules with a singlet ground state, the population of triplet states is mainly possible (a) by direct excitation and subsequent intersystem crossing or (b) energy transfer from an appropriate sensitizer. The latter scenario enables catalytic photochemical reaction in which sensitizer adopts role catalyst undergoing several cycles photon absorption to substrate. If product molecule triplet-sensitized process chiral, this can proceed enantioselectively upon judicious choice chiral An enantioselective also occur dual approach which, apart achiral sensitizer, second activates substrate toward sensitization. Although idea reactions via intermediates has been pursued for more than 50 years, notable selectivities exceeding 90% enantiomeric excess (ee) have only realized past decade. This review attempts provide comprehensive survey on various were rendered

Language: Английский

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Photocatalytic Late-Stage C–H Functionalization

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(8), P. 4237 - 4352

Published: Jan. 24, 2023

The emergence of modern photocatalysis, characterized by mildness and selectivity, has significantly spurred innovative late-stage C–H functionalization approaches that make use low energy photons as a controllable source. Compared to traditional strategies, photocatalysis paves the way toward complementary and/or previously unattainable regio- chemoselectivities. Merging compelling benefits with workflow offers potentially unmatched arsenal tackle drug development campaigns beyond. This Review highlights photocatalytic strategies small-molecule drugs, agrochemicals, natural products, classified according targeted bond newly formed one. Emphasis is devoted identifying, describing, comparing main mechanistic scenarios. draws critical comparison between established ionic chemistry photocatalyzed radical-based manifolds. aims establish current state-of-the-art illustrate key unsolved challenges be addressed in future. authors aim introduce general readership functionalization, specialist practitioners evaluation methodologies, potential for improvement, future uncharted directions.

Language: Английский

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Visible light photoredox-catalysed remote C–H functionalisation enabled by 1,5-hydrogen atom transfer (1,5-HAT)

Chemical Society Reviews, Journal Year: 2021, Volume and Issue: 50(13), P. 7359 - 7377

Published: Jan. 1, 2021

The generation of heteroatom-centred radicals followed by intramolecular 1,5-HAT and functionalisation the translocated carbon-centred radical is an efficient way to functionalize chemo- regio-selectively remote unactivated C(sp³)–H bond.

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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Strategies to Generate Nitrogen-centered Radicals That May Rely on Photoredox Catalysis: Development in Reaction Methodology and Applications in Organic Synthesis

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2353 - 2428

Published: Oct. 8, 2021

For more than 70 years, nitrogen-centered radicals have been recognized as potent synthetic intermediates. This review is a survey designed for use by chemists engaged in target-oriented synthesis. summarizes the recent paradigm shift access to and application of N-centered enabled visible-light photocatalysis. broadens streamlines approaches many small molecules because photocatalysis conditions are mild. Explicit attention paid innovative advances N–X bonds radical precursors, where X = Cl, N, S, O, H. clarity, key mechanistic data noted, available. Synthetic applications limitations summarized illuminate tremendous utility photocatalytically generated radicals.

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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Copper-catalyzed radical relay in C(sp³)–H functionalization

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(5), P. 1640 - 1658

Published: Jan. 1, 2022

Radical-involved transition metal (TM) catalysis has greatly enabled new reactivities in recent decades. Copper-catalyzed radical relay offers enormous potential C(sp3)-H functionalization which combines the unique regioselectivity of hydrogen atom transfer (HAT) and versatility copper-catalyzed cross-coupling. More importantly, significant progress been achieved asymmetric C-H through judicious ligand design. This tutorial review will highlight advances this rapidly growing area, we hope survey inspire future strategic developments for selective functionalization.

Language: Английский

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Photoinduced Copper-Catalyzed Asymmetric C–O Cross-Coupling

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(33), P. 13382 - 13392

Published: Aug. 10, 2021

The construction of carbon–heteroatom bonds is one the most active areas research in organic chemistry because function molecules often derived from presence heteroatoms. Although considerable advances have recently been achieved radical-involved catalytic asymmetric C–N bond formation, there has little progress corresponding C–O bond-forming processes. Here, we describe a photoinduced copper-catalyzed cross-coupling readily available oxime esters and 1,3-dienes to generate diversely substituted allylic with high regio- enantioselectivity (>75 examples; up 95% ee). reaction proceeds at room temperature under excitation by purple light-emitting diodes (LEDs) features use single, earth-abundant copper-based chiral catalyst as both photoredox for radical generation source induction coupling. Combined experimental density functional theory (DFT) computational studies suggest formation π-allylcopper complexes redox-active bifunctional reagents through radical–polar crossover process.

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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