Visible light photocatalysis in the late-stage functionalization of pharmaceutically relevant compounds

Chemical Society Reviews, Journal Year: 2020, Volume and Issue: 50(2), P. 766 - 897

Published: Dec. 22, 2020

Recent developments and future prospects of visible-light photocatalysis in the late-stage functionalization pharmaceuticals natural bioactive compounds.

Language: Английский

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Visible‐Light‐Induced Homolysis of Earth‐Abundant Metal‐Substrate Complexes: A Complementary Activation Strategy in Photoredox Catalysis

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(39), P. 21100 - 21115

Published: Feb. 18, 2021

Abstract The mainstream applications of visible‐light photoredox catalysis predominately involve outer‐sphere single‐electron transfer (SET) or energy (EnT) processes precious metal Ru II Ir III complexes organic dyes with low photostability. Earth‐abundant metal‐based M n L ‐type (M=metal, =polydentate ligands) are rapidly evolving as alternative photocatalysts they offer not only economic and ecological advantages but also access to the complementary inner‐sphere mechanistic modes, thereby transcending their inherent limitations ultrashort excited‐state lifetimes for use effective photocatalysts. generic process, termed visible‐light‐induced homolysis (VLIH), entails formation suitable light‐absorbing ligated metal–substrate (M ‐Z; Z=substrate) that can undergo homolytic cleavage generate n−1 Z . further transformations.

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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A Rational Approach to Organo‐Photocatalysis: Novel Designs and Structure‐Property Relationships

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(3), P. 1082 - 1097

Published: June 22, 2020

Organic photocatalysts are emerging as viable and more sustainable tools than metal complexes. Recently, the field of organo-photocatalysis has experienced an explosion in terms applications, redesign well-established systems, identification novel scaffolds. A rational approach to structural modification different is key accessing unprecedented reactivity, while improving their catalytic performances. We herein discuss concepts underpinning scaffold some most recently used analyze how specific changes alter physicochemical redox properties.

Language: Английский

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A General Organocatalytic System for Electron Donor–Acceptor Complex Photoactivation and Its Use in Radical Processes

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(31), P. 12304 - 12314

Published: July 28, 2021

We report herein a modular class of organic catalysts that, acting as donors, can readily form photoactive electron donor-acceptor (EDA) complexes with variety radical precursors. Excitation visible light generates open-shell intermediates under mild conditions, including nonstabilized carbon radicals and nitrogen-centered radicals. The nature the commercially available xanthogenate dithiocarbamate anion organocatalysts offers versatile EDA complex catalytic platform for developing mechanistically distinct reactions, encompassing redox-neutral net-reductive processes. Mechanistic investigations, by means quantum yield determination, established that closed cycle is operational all developed processes, highlighting ability to turn over iteratively drive every cycle. also demonstrate how catalysts' stability method's high functional group tolerance could be advantageous direct functionalization abundant groups, aliphatic carboxylic acids amines, applications in late-stage elaboration biorelevant compounds enantioselective catalysis.

Language: Английский

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Direct excitation strategy for radical generation in organic synthesis

Chemical Society Reviews, Journal Year: 2021, Volume and Issue: 50(11), P. 6320 - 6332

Published: Jan. 1, 2021

This tutorial review encompasses the radical generation based on classical methods and photoredox catalysis. It will also focus only demanding visible-light, which involves EDA complex direct photo-excitation strategy.

Language: Английский

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A cross-dehydrogenative C(sp3)−H heteroarylation via photo-induced catalytic chlorine radical generation

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: June 29, 2021

Abstract Hydrogen atom abstraction (HAT) from C( sp 3 )–H bonds of naturally abundant alkanes for alkyl radical generation represents a promising yet underexplored strategy in the alkylation reaction designs since involving stoichiometric oxidants, excessive alkane loading, and limited scope are common drawbacks. Here we report photo-induced chemical oxidant-free cross-dehydrogenative coupling (CDC) between heteroarenes using catalytic chloride cobalt catalyst. Couplings strong bond-containing substrates complex heteroarenes, have been achieved with satisfactory yields. This dual platform features situ engendered chlorine exploits cobaloxime catalyst to enable hydrogen evolution turnover. The practical value this protocol was demonstrated by gram-scale synthesis alkylated heteroarene merely equiv. loading.

Language: Английский

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Radical relay cyclization/C–C bond formation of allyloxy-tethered aryl iodides with quinoxalin-2(1H)-ones via polysulfide anion photocatalysis

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(8), P. 1708 - 1713

Published: Jan. 1, 2024

A visible-light-induced radical relay cyclization/C-C bond formation of quinoxalin-2(1

Language: Английский

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Photochemical generation of acyl and carbamoyl radicals using a nucleophilic organic catalyst: applications and mechanism thereof

Chemical Science, Journal Year: 2020, Volume and Issue: 11(24), P. 6312 - 6324

Published: Jan. 1, 2020

We detail a strategy that uses commercially available nucleophilic organic catalyst to generate acyl and carbamoyl radicals upon activation of the corresponding chlorides anhydrides via substitution path. The resulting are then intercepted by variety electron-poor olefins in Giese-type addition process. chemistry requires low-energy photons (blue LEDs) activate radical precursors, which, due their high reduction potential, not readily prone redox-based mechanisms. To elucidate key mechanistic aspects this catalytic photochemical generation strategy, we used combination transient absorption spectroscopy investigations, electrochemical studies, quantum yield measurements, characterization intermediates. identified off-the-cycle intermediates engage light-regulated equilibrium with reactive radicals. These regulated equilibriums cooperate control overall concentrations radicals, contributing efficiency process facilitating turnover catalyst.

Language: Английский

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Using the Thiyl Radical for Aliphatic Hydrogen‐Atom Transfer: Thiolation of Unactivated C−H Bonds

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(6), P. 2849 - 2854

Published: Nov. 4, 2020

Abstract A metal‐ and catalyst‐free thiyl‐radical‐mediated activation of alkanes is described. Tetrafluoropyridinyl disulfide used to perform thiolation the C−H bonds under irradiation with 400 nm light‐emitting diodes. The key step believed proceed via hydrogen‐atom abstraction effected by fluorinated thiyl radical. Secondary, tertiary, heteroatom‐substituted can be involved in reaction. resulting sulfides have wide potential as photoredox‐active radical precursors reactions alkenes heteroarenes.

Language: Английский

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