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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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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Radical C(sp3)–H functionalization and cross-coupling reactions

Nature Reviews Chemistry, Journal Year: 2022, Volume and Issue: 6(6), P. 405 - 427

Published: May 17, 2022

Language: Английский

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Photoelectrochemical asymmetric catalysis enables site- and enantioselective cyanation of benzylic C–H bonds

Nature Catalysis, Journal Year: 2022, Volume and Issue: 5(10), P. 943 - 951

Published: Oct. 10, 2022

Language: Английский

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Photoinduced Copper‐Catalyzed Asymmetric Three‐Component Coupling of 1,3‐Dienes: An Alternative to Kharasch–Sosnovsky Reaction

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(42), P. 22956 - 22962

Published: Aug. 18, 2021

Abstract Kharasch–Sosnovsky reaction is one of the most powerful methods for allylic oxidation alkenes. However, inherent radical mechanism and use peroxides as both oxidants oxygen nucleophiles render dearth universal catalytic systems highly enantioselective variants limited scope. Herein, an alternative to asymmetric that utilized a chiral copper catalyst purple‐LED irradiation enable three‐component coupling 1,3‐dienes, oxime esters, carboxylic acids reported. This protocol features mild conditions, remarkable scope functional group tolerance evidenced by >80 examples utility in late‐stage modification pharmaceuticals natural products. Detailed mechanistic studies provide evidences radical‐based pathway.

Language: Английский

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Electronic control over site-selectivity in hydrogen atom transfer (HAT) based C(sp³)–H functionalization promoted by electrophilic reagents

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(6), P. 2171 - 2223

Published: Jan. 1, 2022

Leveraging on electronic effects in both the substrate and HAT reagent, site-selectivity can be implemented C(sp 3 )–H bond functionalization.

Language: Английский

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Modular Access to Chiral α-(Hetero)aryl Amines via Ni/Photoredox-Catalyzed Enantioselective Cross-Coupling

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(19), P. 8797 - 8806

Published: May 3, 2022

Chiral α-aryl N-heterocycles are commonly found in natural products, pharmaceutical agents, and chiral catalysts but remain challenging to access via asymmetric catalysis. Herein, we report a general modular approach for the direct enantioselective α-arylation of saturated azacycles acyclic N-alkyl benzamides nickel/photoredox dual This process exploits hydrogen atom transfer ability photoeliminated chlorine radicals convert corresponding α-amino alkyl that then coupled with ubiquitous inexpensive (hetero)aryl chlorides. These coupling reactions require no oxidants or organometallic reagents, feature feedstock starting materials, broad substrate scope, high enantioselectivities, applicable late-stage diversification medicinally relevant complex molecules. Mechanistic studies suggest nickel catalyst uncommonly plays multiple roles, accomplishing radical generation, capture, cross-coupling, induction.

Language: Английский

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Electrophotocatalytic Decoupled Radical Relay Enables Highly Efficient and Enantioselective Benzylic C–H Functionalization

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(47), P. 21674 - 21682

Published: Nov. 17, 2022

Asymmetric sp3 C–H functionalization has been demonstrated to substantially expedite target molecule synthesis, spanning from feedstocks upgradation late-stage modification of complex molecules. Herein, we report a highly efficient and sustainable method for enantioselective benzylic cyanation by merging electrophoto- copper catalysis. A novel catalytic system allows one independently regulate the hydrogen atom transfer step radical formation speciation Cu(II)/Cu(I) effectively capture transient intermediate, through tuning electronic property anthraquinone-type photocatalyst simply modulating applied current, respectively. Such decoupled relay catalysis enables unified approach diverse alkylarenes, many which are much less reactive or even unreactive using existing relying on coupled relay. Moreover, current protocol is also amenable bioactive molecules, including natural products drugs.

Language: Английский

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Directed evolution of nonheme iron enzymes to access abiological radical-relay C(sp ³ )−H azidation

Science, Journal Year: 2022, Volume and Issue: 376(6595), P. 869 - 874

Published: May 19, 2022

We report the reprogramming of nonheme iron enzymes to catalyze an abiological C(sp3)‒H azidation reaction through iron-catalyzed radical relay. This biocatalytic transformation uses amidyl radicals as hydrogen atom abstractors and Fe(III)‒N3 intermediates trapping agents. established a high-throughput screening platform based on click chemistry for rapid evolution catalytic performance identified enzymes. The final optimized variants deliver range products with up 10,600 total turnovers 93% enantiomeric excess. Given prevalence relay reactions in organic synthesis diversity enzymes, we envision that this discovery will stimulate future development metalloenzyme catalysts synthetically useful transformations unexplored by natural evolution.

Language: Английский

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A light-driven enzymatic enantioselective radical acylation

Nature, Journal Year: 2023, Volume and Issue: 625(7993), P. 74 - 78

Published: Dec. 18, 2023

Language: Английский

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