Technological Innovations in Photochemistry for Organic Synthesis: Flow Chemistry, High-Throughput Experimentation, Scale-up, and Photoelectrochemistry

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2752 - 2906

Published: Aug. 10, 2021

Photoinduced chemical transformations have received in recent years a tremendous amount of attention, providing plethora opportunities to synthetic organic chemists. However, performing photochemical transformation can be quite challenge because various issues related the delivery photons. These challenges barred widespread adoption steps industry. past decade, several technological innovations led more reproducible, selective, and scalable photoinduced reactions. Herein, we provide comprehensive overview these exciting advances, including flow chemistry, high-throughput experimentation, reactor design scale-up, combination photo- electro-chemistry.

Language: Английский

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Triplet Energy Transfer Photocatalysis: Unlocking the Next Level

Chem, Journal Year: 2020, Volume and Issue: 6(8), P. 1888 - 1903

Published: Aug. 1, 2020

Language: Английский

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Advances in theE → ZIsomerization of Alkenes Using Small Molecule Photocatalysts

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2650 - 2694

Published: Aug. 27, 2021

Geometrical E → Z alkene isomerization is intimately entwined in the historical fabric of organic photochemistry and enjoying a renaissance (Roth et al. Angew. Chem., Int. Ed. Engl. 1989 28, 1193–1207). This consequence fundamental stereochemical importance Z-alkenes, juxtaposed with frustrations thermal reactivity that are rooted microscopic reversibility. Accessing excited state paradigms allow this latter obstacle to be circumnavigated by exploiting subtle differences photophysical behavior substrate product chromophores: provides molecular basis for directionality. While direct irradiation operationally simple, photosensitization via selective energy transfer enables augmentation repertoire include substrates not directly photons. Through sustained innovation, an impressive portfolio tailored small molecule catalysts range triplet energies now widely available facilitate contra-thermodynamic thermo-neutral reactions generate Z-alkene fragments. review intended serve as practical guide covering geometric alkenes enabled catalysis from 2000 2020, logical sequel excellent treatment Dugave Demange (Chem. Rev. 2003 103, 2475–2532). The mechanistic foundations underpinning selectivity discussed together induction models rationales explain counterintuitive directionality these processes which very distinguish product. Implications subsequent stereospecific transformations, application total synthesis, regioselective polyene isomerization, spatiotemporal control pre-existing configuration broader sense discussed.

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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Acridinium Salts and Cyanoarenes as Powerful Photocatalysts: Opportunities in Organic Synthesis

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(36), P. 19526 - 19549

Published: April 22, 2021

The use of organic photocatalysts has revolutionized the field photoredox catalysis, as it allows access to reactivities that were traditionally restricted transition-metal photocatalysts. This Minireview reports recent developments in acridinium ions and cyanoarene derivatives synthesis. activation inert chemical bonds well late-stage functionalization biorelevant molecules are discussed, with a special focus on their mechanistic aspects.

Language: Английский

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Boron-enabled geometric isomerization of alkenes via selective energy-transfer catalysis

Science, Journal Year: 2020, Volume and Issue: 369(6501), P. 302 - 306

Published: July 17, 2020

An E-Z boron swivel Compounds with carbon-carbon double bonds can form two distinct isomers, depending on whether the heaviest substituents both carbons lie same side (labeled Z) or diagonally across from each other E). Molloy et al. present a convenient method to reorient that bear and carbonyl substituents. When they are opposed, stay in plane, bond is easily swiveled by photosensitization. However, once as carbonyl, rotates out of plane further sensitization inhibited. Science this issue p. 302

Language: Английский

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Transition metal-catalyzed alkene isomerization as an enabling technology in tandem, sequential and domino processes

Chemical Society Reviews, Journal Year: 2020, Volume and Issue: 50(2), P. 1391 - 1406

Published: Dec. 10, 2020

One-pot reactions based on catalytic isomerization of alkenes not only offer the inherent advantages atom-, step- and redox-economy but also enable preparation value-added products that would be difficult to access by conventional methods.

Language: Английский

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Synthetic Molecular Photoelectrochemistry: New Frontiers in Synthetic Applications, Mechanistic Insights and Scalability

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 61(12)

Published: Sept. 3, 2021

Synthetic photoelectrochemistry (PEC) is receiving increasing attention as a new frontier for the generation and handling of reactive intermediates. PEC permits selective single-electron transfer (SET) reactions in much greener way broadens redox window possible transformations. Herein, most recent contributions are reviewed, demonstrating exciting opportunities, namely, combination with other reactivity paradigms (hydrogen-atom transfer, radical polar crossover, energy sensitization), scalability up to multigram scale, novel selectivities SET super-oxidations/reductions importance precomplexation temporally enable excited ion catalysis.

Language: Английский

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Transition-Metal-Catalyzed Functionalization of Alkynes with Organoboron Reagents: New Trends, Mechanistic Insights, and Applications

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(12), P. 7513 - 7551

Published: June 9, 2021

Catalytic functionalization of alkynes with organoboron reagents provides a straightforward access to stereochemically defined multisubstituted alkenes, which are structural motifs commonly found in bioactive compounds and organic materials. Recent progress has substantially broadened the scope this field on several fronts. Strategies for regioselectivity control 1,2-migratory insertion across unsymmetrical internal alkynes, as well direct products anti-insertion stereochemistry, have been devised. The alkenyl-to-aryl 1,4-metal migration upon metal recently exploited powerful cascade sequences leading complex polycyclic scaffolds, including development enantioselective processes. Elegant enantiospecific dynamic kinetic resolution methods developed accessing chiral allenes from propargylic alcohol derivatives. Mechanistic manifolds emerged based single-electron transfer (SET) that provided fresh impetus alkyne 1,2-difunctionalization complementary stereoselectivity processes relying 1,2-insertion R–M species. Herein, we discuss most recent advances transition-metal-catalyzed using reagents, categorized according type mechanistic outcome. Emphasis is placed aspects, synthetic utility, limitations, challenges future research.

Language: Английский

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Site-Selective Acceptorless Dehydrogenation of Aliphatics Enabled by Organophotoredox/Cobalt Dual Catalysis

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(40), P. 16470 - 16485

Published: Sept. 30, 2021

The value of catalytic dehydrogenation aliphatics (CDA) in organic synthesis has remained largely underexplored. Known homogeneous CDA systems often require the use sacrificial hydrogen acceptors (or oxidants), precious metal catalysts, and harsh reaction conditions, thus limiting most existing methods to non- or low-functionalized alkanes. Here we describe a visible-light-driven, dual-catalyst system consisting inexpensive organophotoredox base-metal catalysts for room-temperature, acceptorless-CDA (Al-CDA). Initiated by photoexited 2-chloroanthraquinone, process involves H atom transfer (HAT) form alkyl radicals, which then react with cobaloxime produce olefins H2. This operationally simple method enables direct readily available chemical feedstocks diversely functionalized olefins. For example, demonstrate, first time, oxidant-free desaturation thioethers amides alkenyl sulfides enamides, respectively. Moreover, system's exceptional site selectivity functional group tolerance are illustrated late-stage 14 biologically relevant molecules pharmaceutical ingredients. Mechanistic studies have revealed dual HAT provided insights into origin reactivity selectivity.

Language: Английский

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