2.9 Fluorination Enabled by Photoredox Reactions DOI
Takashi Koike

Published: Jan. 1, 2024

Abstract In recent years, photoredox catalysis has become a useful strategy in the field of synthetic chemistry because generation reactive radicals, ionic species, and organometallics under mild reaction conditions can be realized. This review mainly discusses fluorination reactions carbon skeletons using catalysis. addition, seminal works on photochemical hydrogen-atom transfer (HAT) photocatalyst-free photoinduced electron-transfer systems are also handled. These applied to C—H bonds, C—C C=C appropriate functional groups.

Language: Английский

Cobalt/Photoredox Dual-Catalyzed Cross-Radical Coupling of Alkenes via Hydrogen Atom Transfer and Homolytic Substitution DOI

Yuto Yamaguchi,

Yuuki Hirata, Kosuke Higashida

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: 26(23), P. 4893 - 4897

Published: June 5, 2024

Cobalt-catalyzed metal hydride hydrogen atom transfer (MHAT) in combination with photoredox catalysis has emerged as a powerful synthetic method, owing to its redox nature and applicability various radical precursors. Herein, we describe cross-radical coupling reaction under cobalt/photoredox dual catalysis. MHAT homolytic substitution (SH2) processes enabled Markovnikov-selective hydrobenzylation of di/trisubstituted alkenes, affording products quaternary carbon center redox-neutral manner.

Language: Английский

Citations

2
Harnessing the potential of acyl triazoles in bifunctional cobalt-catalyzed radical cross-coupling reactions DOI Creative Commons
Chang‐Yin Tan, Sungwoo Hong

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Aug. 13, 2024

Persistent radicals facilitate numerous selective radical coupling reactions. Here, we have identified acyl triazole as a new and versatile moiety for generating persistent intermediates through single-electron transfer processes. The efficient generation of these is facilitated by the formation substrate-coordinated cobalt complexes, which subsequently engage in cross-coupling Remarkably, triazole-coordinated complexes exhibit metal-hydride hydrogen atom (MHAT) capabilities with alkenes, enabling synthesis diverse ketone products without need external ligands. By leveraging effect, this catalytic approach also allows development other reactions two representative precursors. discovery triazoles effective substrates ligands catalysis, combined bifunctional nature system, opens up avenues design sustainable organic transformations. radical-mediated has emerged powerful tool forging C–C bonds. authors identify processes, context cobalt-catalysed carbon-carbon couplings under photoirradiation.

Language: Английский

Citations

2
Formation of TEMPO Adducts with Hydrogen Atom Transfer: A New Pathway to Versatile Hydrofunctionalizations of Olefins DOI Creative Commons
Chengbo Yao, Muinat A. Aliyu, Jack R. Norton

et al.

Published: Feb. 12, 2024

Since the seminal work by Mukaiyama, many research groups reported hydrofunctionalization of olefin with different metal hydrides in situ. Despite rapid development MHAT (metal-catalyzed hydrogen atom transfer)-derived reactions, need for using catalyst systems to accommodate reactivities makes it not appealing. Here, we describe a two-step process access broad range olefins. The first step involves cobalt-catalyzed formation TEMPO adduct from reaction demonstrates substrate scope and functional group tolerance. second photocatalytic nucleophilic addition generate new C-C, C-N, C-O, C-F, C-Cl bond. Interestingly our methodology, fluorination could be achieved short time, showing its potential PET applications. Combining two steps, net olefins can simply changing nucleophiles step. Noteworthily, diastereoselective hydration was also demonstrated employing bulkiness TEMPO.

Language: Английский

Citations

1
Dual‐Catalytic Structural Isomerisation as a Route to α‐Arylated Ketones DOI Creative Commons

Danijela Lunic,

Nikita Vystavkin,

Jingyang Qin

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(44)

Published: July 9, 2024

Abstract Isomerisation reactions provide streamlined routes to organic compounds which are otherwise hard directly synthesise. The most common forms positional, geometrical or stereochemical isomerisations involve the relocation of a double bond change in relative location groups space. In contrast, far fewer examples structural (or constitutional) isomerisation exist where connectivity between atoms is altered. development platforms capable such rearrangement poses unique set challenges because chemical bonds must be selectively cleaved, and new ones formed without overall addition removal atoms. Here, we show that dual catalytic system can enable readily available allylic alcohols into more challenging‐to‐synthesise α‐arylated ketones via H‐atom transfer initiated semi‐pinacol rearrangement. Key our strategy combination cobalt catalyst photocatalyst under reductive, protic conditions allows intermediates propagate turnover. By providing an unusual disconnection motifs difficult access through direct arylation, anticipate inspiring other advanced strategies will further retrosynthetic logic for complex molecule synthesis.

Language: Английский

Citations

1
Practical and regioselective halonitrooxylation of olefins to access β-halonitrates DOI Creative Commons
Cheng Xuan,

Quan Yin,

Yifei Cheng

et al.

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Aug. 20, 2024

Organic nitrates, as effective donors of the signaling molecule nitric oxide, are widely applied in pharmaceutical industry. However, practical and efficient methods for accessing organic nitrates still scarce, achieving high regiocontrol unactivated alkene difunctionalization remains challenging. Here we present a simple method highly regioselective halonitrooxylation alkenes. The approach utilizes TMSX (X: Cl, Br, or I) oxybis(aryl-λ

Language: Английский

Citations

1
Shuttle HAT for mild alkene transfer hydrofunctionalization DOI Creative Commons
Tanner C. Jankins, Philip M. Blank,

Andrea Brugnetti

et al.

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Oct. 30, 2024

Hydrogen atom transfer (HAT) from a metal-hydride is reliable and powerful method for functionalizing unsaturated C-C bonds in organic synthesis. Cobalt hydrides (Co-H) have garnered significant attention this field, where the weak Co-H are most commonly generated catalytic fashion through mixture of stoichiometric amounts peroxide oxidant silane reductant. Here we show that reverse process HAT to an alkene, i.e. hydrogen abstraction C-H adjacent radical, can be leveraged generate catalytically active species application shuttle catalysis coined HAT. This obviates need reductant/oxidant mixtures thereby greatly simplifying generation Co-H. To demonstrate generality platform, five different reaction manifolds shown, easily scaled up 100 mmol.

Language: Английский

Citations

1
Illuminating cobalt co-catalysis DOI
Jianbin Li

Trends in Chemistry, Journal Year: 2024, Volume and Issue: 6(4), P. 161 - 163

Published: March 28, 2024

Language: Английский

Citations

0
Hydrohalogenation of Alkenes Using Collidine·HX Salts under Dual Cobalt and Photoredox Catalysis DOI Open Access
Martin Oestreich, Hendrik F. T. Klare, Phillip Pommerening

et al.

Synfacts, Journal Year: 2024, Volume and Issue: 20(05), P. 0479 - 0479

Published: April 15, 2024

Key words alkenes - cobalt catalysis hydrohalogenation photoredox

Language: Английский

Citations

0
Cobalt‐Catalyzed Photo‐Semipinacol Rearrangement of Unactivated Allylic Alcohols DOI Creative Commons
Erick M. Carreira, Henry Lindner

Angewandte Chemie, Journal Year: 2024, Volume and Issue: 136(35)

Published: June 7, 2024

Abstract Eine photochemische Methode für die Semipinakol‐Umlagerung von nichtaktivierten Allylalkoholen wird beschrieben. Die Bedingungen erlauben Umlagerung sowohl aliphatischer als auch aromatischer Reste und formen eine Vielzahl α,α‐disubstituierten Ketonen. Reaktion erfolgt unter milden toleriert anderem Ether, Ester, Halogene, Nitrile, Carbamate substituierte Arene. operativ einfachen vollständig katalytischen erfordern 1 mol % Benzothiazinoquinoxalin Organophotokatalysator, 0,5 Co‐Salen 10 Lutidiniumtriflat ermöglichen Reaktivität, komplementär zu der mit Brønsted‐Säure beobachteten ist. Wir demonstrieren den Nutzen des Protokolls Diversifizierung Arzneistoffen.

Citations

0
Dual‐Catalytic Structural Isomerisation as a Route to α‐Arylated Ketones DOI Creative Commons

Danijela Lunic,

Nikita Vystavkin,

Jingyang Qin

et al.

Angewandte Chemie, Journal Year: 2024, Volume and Issue: 136(44)

Published: July 9, 2024

Abstract Isomerisation reactions provide streamlined routes to organic compounds which are otherwise hard directly synthesise. The most common forms positional, geometrical or stereochemical isomerisations involve the relocation of a double bond change in relative location groups space. In contrast, far fewer examples structural (or constitutional) isomerisation exist where connectivity between atoms is altered. development platforms capable such rearrangement poses unique set challenges because chemical bonds must be selectively cleaved, and new ones formed without overall addition removal atoms. Here, we show that dual catalytic system can enable readily available allylic alcohols into more challenging‐to‐synthesise α‐arylated ketones via H‐atom transfer initiated semi‐pinacol rearrangement. Key our strategy combination cobalt catalyst photocatalyst under reductive, protic conditions allows intermediates propagate turnover. By providing an unusual disconnection motifs difficult access through direct arylation, anticipate inspiring other advanced strategies will further retrosynthetic logic for complex molecule synthesis.

Language: Английский

Citations

0