Visible Light-Driven Radical-Mediated C–C Bond Cleavage/Functionalization in Organic Synthesis

Chemical Reviews, Journal Year: 2020, Volume and Issue: 121(1), P. 506 - 561

Published: May 29, 2020

Thermal C–C bond cleavage reactions allow the construction of structurally diverse molecular skeletons via predictable and efficient reorganizations. Visible light photoredox-catalyzed radical-mediated have recently emerged as a powerful alternative method for overcoming thermodynamic kinetic barrier in scaffolds. In recent years, plethora elegant useful been invented, products are sometimes otherwise inaccessible by classic thermal reactions. Considering great influence synthetic potential these reactions, we provide summary state art visible light-driven cleavage/functionalization strategies with specific emphasis on working models. We hoped that this review will be medicinal organic chemists inspire further reaction development interesting area.

Language: Английский

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The Persistent Radical Effect in Organic Synthesis

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(1), P. 74 - 108

Published: May 22, 2019

Abstract Radical–radical couplings are mostly nearly diffusion‐controlled processes. Therefore, the selective cross‐coupling of two different radicals is challenging and not a synthetically valuable transformation. However, if have lifetimes they generated at equal rates, will become dominant process. This high cross‐selectivity based on kinetic phenomenon called persistent radical effect (PRE). In this Review, an explanation PRE supported by simulations simple model systems provided. Radical stabilities discussed within context their lifetimes, various examples PRE‐mediated radical–radical in synthesis summarized. It shown that restricted to coupling with transient radical. If one partner longer‐lived than other radical, operates achieved. important point expands scope chemistry. The Review divided into parts, namely 1) or organic 2) “radical–metal crossover reactions”; here, metal‐centered species more generally transition‐metal complexes able react discussed—a field has flourished recently.

Language: Английский

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Late-stage C–H functionalization offers new opportunities in drug discovery

Nature Reviews Chemistry, Journal Year: 2021, Volume and Issue: 5(8), P. 522 - 545

Published: July 13, 2021

Language: Английский

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Nickel-Catalyzed Enantioselective Reductive Cross-Coupling Reactions

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(15), P. 8237 - 8246

Published: June 24, 2020

Nickel-catalyzed reductive cross-coupling reactions have emerged as powerful methods to join two electrophiles. These proven particularly useful for the coupling of sec-alkyl electrophiles form stereogenic centers; however, development enantioselective variants remains challenging. In this Perspective, we summarize progress that has been made toward Ni-catalyzed reactions.

Language: Английский

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Mechanisms of Nickel-Catalyzed Cross-Coupling Reactions

Trends in Chemistry, Journal Year: 2019, Volume and Issue: 1(9), P. 830 - 844

Published: Sept. 13, 2019

Language: Английский

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New Redox Strategies in Organic Synthesis by Means of Electrochemistry and Photochemistry

ACS Central Science, Journal Year: 2020, Volume and Issue: 6(8), P. 1317 - 1340

Published: July 16, 2020

As the breadth of radical chemistry grows, new means to promote and regulate single-electron redox activities play increasingly important roles in driving modern synthetic innovation. In this regard, photochemistry electrochemistry-both considered as niche fields for decades-have seen an explosive renewal interest recent years gradually have become a cornerstone organic chemistry. Outlook article, we examine current state-of-the-art areas electrochemistry photochemistry, well nascent area electrophotochemistry. These techniques employ external stimuli activate molecules imbue privileged control reaction progress selectivity that is challenging traditional chemical methods. Thus, they provide alternative entries known reactive intermediates enable distinct strategies were previously unimaginable. Of many hallmarks, electro- are often classified "green" technologies, promoting reactions under mild conditions without necessity potent wasteful oxidants reductants. This reviews most growth these with special emphasis on conceptual advances given rise enhanced accessibility tools trade.

Language: Английский

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Generation of Alkyl Radicals: From the Tyranny of Tin to the Photon Democracy

Chemical Reviews, Journal Year: 2020, Volume and Issue: 120(17), P. 9790 - 9833

Published: Aug. 6, 2020

Alkyl radicals are key intermediates in organic synthesis. Their classic generation from alkyl halides has a severe drawback due to the employment of toxic tin hydrides point that "flight tyranny tin" radical processes was considered for long time an unavoidable issue. This review summarizes main alternative approaches unstabilized radicals, using photons as traceless promoters. The recent development photochemical and photocatalyzed enabled discovery plethora new precursors, opening world chemistry broader community, thus allowing era photon democracy.

Language: Английский

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Photons or Electrons? A Critical Comparison of Electrochemistry and Photoredox Catalysis for Organic Synthesis

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2487 - 2649

Published: Nov. 9, 2021

Redox processes are at the heart of synthetic methods that rely on either electrochemistry or photoredox catalysis, but how do and catalysis compare? Both approaches provide access to high energy intermediates (e.g., radicals) enable bond formations not constrained by rules ionic 2 electron (e) mechanisms. Instead, they 1e mechanisms capable bypassing electronic steric limitations protecting group requirements, thus enabling chemists disconnect molecules in new different ways. However, while providing similar intermediates, differ several physical chemistry principles. Understanding those differences can be key designing transformations forging disconnections. This review aims highlight these similarities between comparing their underlying principles describing impact electrochemical photochemical methods.

Language: Английский

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Mechanisms of Nickel-Catalyzed Coupling Reactions and Applications in Alkene Functionalization

Accounts of Chemical Research, Journal Year: 2020, Volume and Issue: 53(4), P. 906 - 919

Published: April 2, 2020

ConspectusNickel complexes exhibit distinct properties from other group 10 metals, including a small nuclear radius, high paring energy, low electronegativity, and redox potentials. These enable Ni catalysts to accommodate stabilize paramagnetic intermediates, access radical pathways, undergo slow β-H elimination. Our research program investigates how each of these fundamental attributes impact the catalytic Ni, in particular context alkene functionalization.Alkenes are versatile functional groups, but stereoselective carbofunctionalization reactions alkenes have been underdeveloped. This challenge may derive difficulty controlling selectivity via traditional two-electron migratory insertion pathways. could lead different stereodetermining steps mechanisms, allowing molecular scaffolds that otherwise difficult prepare. For example, an asymmetric diarylation reaction developed by our relies upon Ni(III) intermediates control enantioselectivity give library chiral α,α,β-triarylethane molecules with biological activity.Mechanistic studies on two-component reductive 1,2-difunctionalization shed light origin cross-electrophile selectivity, as C sp2 sp3 electrophiles independently activated at Ni(I) respectively. Catalyst reduction has identified be turnover-limiting step this system. A closer investigation formation using (Xantphos)Ni(I)Ar model complex reveals initiates concerted halogen-abstraction pathway.The potentials allowed us develop reductive, trans-selective diene cyclization, wherein classic mechanism operates Ni(I)/Ni(III) platform, accounting for chemo- stereoselectivity. found applications efficient synthesis pharmaceutically relevant molecules, such 3,4-dimethylgababutin.The tendency one-electron processes prompted explore dinuclear Ni-mediated bond formations. provide insight into Ni–Ni bonding two metal centers react cooperatively promote C–C, C–X, N–N forming elimination.Finally, isolation β-agostic Pd X-ray neutron diffraction characterization highly reactive molecules. The parameters serve unambiguous evidence interactions help rationalize slower elimination relative Pd. Overall, elucidated several contexts. Greater mechanistic understanding facilitates catalyst design helps reactivity Ni-catalyzed functionalization reactions.

Language: Английский

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Chemistry glows green with photoredox catalysis

Nature Communications, Journal Year: 2020, Volume and Issue: 11(1)

Published: Feb. 6, 2020

Can organic chemistry mimic nature in efficiency and sustainability? Not yet, but recent developments photoredox catalysis animated the synthetic field, providing greener opportunities for industry academia.

Language: Английский

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