Photocatalysis in the Life Science Industry

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2907 - 2980

Published: Sept. 24, 2021

In the pursuit of new pharmaceuticals and agrochemicals, chemists in life science industry require access to mild robust synthetic methodologies systematically modify chemical structures, explore novel space, enable efficient synthesis. this context, photocatalysis has emerged as a powerful technology for synthesis complex often highly functionalized molecules. This Review aims summarize published contributions field from industry, including research industrial-academic partnerships. An overview developed strategic applications synthesis, peptide functionalization, isotope labeling, both DNA-encoded traditional library is provided, along with summary state-of-the-art photoreactor effective upscaling photocatalytic reactions.

Language: Английский

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Synthetic and Mechanistic Implications of Chlorine Photoelimination in Nickel/Photoredox C(sp³)–H Cross-Coupling

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(4), P. 988 - 1000

Published: Jan. 29, 2021

ConspectusIn recent years, the development of light-driven reactions has contributed numerous advances in synthetic organic chemistry. A particularly active research area combines photoredox catalysis with nickel to accomplish otherwise inaccessible cross-coupling reactions. In these reactions, catalyst absorbs light generate an electronically excited charge-transfer state that can engage electron or energy transfer a substrate and catalyst. Our group questioned whether photoinduced activation itself could also contribute new approaches cross-coupling. Over past 5 we have sought advance this hypothesis for suite mild site-selective C(sp3)–H chloride-containing coupling partners via photoelimination Ni–Cl bond.On basis report from Nocera laboratory, reasoned photolysis Ni(III) aryl chloride species, generated by single-electron oxidation typical Ni(II) intermediate cross-coupling, might allow catalytic generation chlorine atoms. Combining ability accept alkyl radicals, hypothesized photocatalytically atoms mediate hydrogen atom (HAT) bonds substrate-derived radical is captured Ni center was envisioned promote necessary reduction facilitate overall redox-neutral process. Overall, strategy would offer visible-light-driven mechanism formation enabled sequential capture two photons.As initial demonstration, developed Ni/photoredox-catalyzed α-oxy arylation cyclic acyclic ethers. This method extended formylation abundant complex chlorides through selective 2-functionalization 1,3-dioxolane. Seeking develop introduce carbon at all different states, explored trimethyl orthoformate, common laboratory solvent. We found orthoformate serves as source methyl methylation reaction β-scission tertiary upon chlorine-mediated HAT. Since capable abstracting unactivated bonds, our efforts been directed range feedstock chemicals, such alkanes toluenes, along late-stage intermediates, using chloroformates partners. platform enables access valuable transformations (hetero)aryl chlorides, which despite being most ubiquitous inexpensive halide partners, are rarely reactive Ni/photoredox catalysis.Little known about photophysics photochemistry organometallic complexes relevant conducted mechanistic investigations, including computational, spectroscopic, emission quenching, stoichiometric studies, These studies indicate operative described functionalization methods. More generally, illustrate catalysts cannot be ignored metallaphotoredox anticipate further understanding should design lead

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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Hydrogen Atom Transfer Reactions via Photoredox Catalyzed Chlorine Atom Generation

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(48), P. 15664 - 15669

Published: Oct. 8, 2018

Abstract The selective functionalization of chemically inert C−H bonds remains to be fully realized in achieving organic transformations that are redox‐neutral, waste‐limiting, and atom‐economical. catalytic generation chlorine atoms from chloride ions is one the most challenging redox processes, where requirement harsh oxidizing reaction conditions renders it seldom utilized synthetic applications. We report mild, controlled, as a new opportunity for access wide variety hydrogen atom transfer (HAT) reactions owing high stability HCl. discovery photoredox mediated with Ir‐based polypyridyl complex, [Ir(dF(CF 3 )ppy) 2 (dtbbpy)]Cl, under blue LED irradiation reported.

Language: Английский

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Cerium-Catalyzed C–H Functionalizations of Alkanes Utilizing Alcohols as Hydrogen Atom Transfer Agents

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(13), P. 6216 - 6226

Published: March 17, 2020

Modern photoredox catalysis has traditionally relied upon metal-to-ligand charge-transfer (MLCT) excitation of metal polypyridyl complexes for the utilization light energy activation organic substrates. Here, we demonstrate catalytic application ligand-to-metal (LMCT) cerium alkoxide facile alkanes utilizing abundant and inexpensive trichloride as catalyst. As demonstrated by cerium-catalyzed C–H amination alkylation hydrocarbons, this reaction manifold enabled use alcohols practical selective hydrogen atom transfer (HAT) agents via direct access energetically challenging alkoxy radicals. Furthermore, LMCT event been investigated through a series spectroscopic experiments, revealing rapid bond homolysis process an effective production radicals, collectively ruling out LMCT/homolysis rate-determining step functionalization.

Language: Английский

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Dual Photoredox/Nickel‐Catalyzed Three‐Component Carbofunctionalization of Alkenes

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(35), P. 12286 - 12290

Published: June 26, 2019

Abstract The potential of merging photoredox and nickel catalysis to perform multicomponent alkene difunctionalizations under visible‐light irradiation is demonstrated here. Secondary tertiary alkyl groups, as well sulfonyl moieties can be added the terminal position double bond with simultaneous arylation internal carbon atom in a single step mild reaction conditions. process, devoid stoichiometric additives, benefits from use bench‐stable easy‐to‐handle reagents, operationally simple, tolerates wide variety functional groups.

Language: Английский

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Catalytic asymmetric allylation of aldehydes with alkenes through allylic C(sp³)–H functionalization mediated by organophotoredox and chiral chromium hybrid catalysis

Chemical Science, Journal Year: 2019, Volume and Issue: 10(12), P. 3459 - 3465

Published: Jan. 1, 2019

We have developed a catalytic asymmetric nucleophilic allylation of aldehydes using simple alkenes as pronucleophiles without relying on stoichiometric metals.

Language: Английский

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Visible light-induced direct α C–H functionalization of alcohols

Nature Communications, Journal Year: 2019, Volume and Issue: 10(1)

Published: Jan. 28, 2019

Abstract Considering the synthetic value of introducing active alcoholic hydroxyl group, developing C–H functionalization alcohols is significance. Herein, we present a photochemical method that under visible light irradiation, selectfluor can effectively promote oxidative cross-coupling between and heteroarenes without external photocatalysis, achieving selective α sp 3 arylation alcohol, even in presence ether. The N-F activation blue LEDs irradiation evidenced by electron paramagnetic resonance (EPR) study, which key process for alcohols. observed reactivity may have significant implications chemical transformations.

Language: Английский

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Electrochemistry Broadens the Scope of Flavin Photocatalysis: Photoelectrocatalytic Oxidation of Unactivated Alcohols

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(1), P. 409 - 417

Published: Oct. 16, 2019

Riboflavin-derived photocatalysts have been extensively studied in the context of alcohol oxidation. However, to date, scope this catalytic methodology has limited benzyl alcohols. In work, mechanistic understanding flavin-catalyzed oxidation reactions, either absence or presence thiourea as a cocatalyst, was obtained. The insights enabled development an electrochemically driven photochemical primary and secondary aliphatic alcohols using pair flavin dialkylthiourea catalysts. Electrochemistry makes it possible avoid O2 oxidant generating H2O2 byproduct, both which oxidatively degrade under reaction conditions. This modification unlocks new pathway unactivated is achieved by thiyl radical mediated hydrogen-atom abstraction.

Language: Английский

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The Dual Role of Benzophenone in Visible‐Light/Nickel Photoredox‐Catalyzed C−H Arylations: Hydrogen‐Atom Transfer and Energy Transfer

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(11), P. 3566 - 3570

Published: Feb. 18, 2019

A dual catalytic protocol for the direct arylation of non-activated C(sp3 )-H bonds has been developed. Upon photochemical excitation, excited triplet state a diaryl ketone photosensitizer abstracts hydrogen atom from an aliphatic C-H bond. This inherent reactivity was exploited generation benzylic radicals which subsequently enter nickel cycle, accomplishing arylation.

Language: Английский

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