Discovery and Elucidation of Counteranion Dependence in Photoredox Catalysis DOI
Elliot P. Farney, Steven J. Chapman, Wesley B. Swords

et al.

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(15), P. 6385 - 6391

Published: March 21, 2019

Over the past decade, there has been a renewed interest in use of transition metal polypyridyl complexes as photoredox catalysts for variety innovative synthetic applications. Many derivatives these are known, and effect ligand modifications on their efficacy subject extensive, systematic investigation. However, influence photocatalyst counteranion received little attention, despite fact that generally cationic nature. Herein, we demonstrate effects exert surprising, dramatic impact rate representative photocatalytic radical cation Diels–Alder reaction. A detailed analysis reveals identity impacts multiple aspects reaction mechanism. Most notably, photocatalysts with more noncoordinating counteranions yield powerful triplet excited state oxidant longer chain length. It is proposed this arises from Coulombic ion-pairing interactions between both catalyst intermediate, respectively. The comparatively slower coordinating can be rescued by using hydrogen-bonding anion binders attenuate deleterious interactions. These results importance variable design optimization transformations suggest novel strategy organic reactions class photocatalysts.

Language: Английский

Photoenzymatic enantioselective intermolecular radical hydroamination DOI
Zhengyi Zhang, Jianqiang Feng, Chao Yang

et al.

Nature Catalysis, Journal Year: 2023, Volume and Issue: 6(8), P. 687 - 694

Published: July 31, 2023

Language: Английский

Citations

52
Organocatalytic Enantioselective Addition of α-Aminoalkyl Radicals to Isoquinolines DOI
Xiangyuan Liu, Yang Liu,

Guobi Chai

et al.

Organic Letters, Journal Year: 2018, Volume and Issue: 20(19), P. 6298 - 6301

Published: Sept. 26, 2018

With a dual organocatalytic system involving chiral phosphoric acid and dicyanopyrazine-derived chromophore (DPZ) photosensitizer under the irradiation with visible light, an enantioselective Minisci-type addition of α-amino acid-derived redox-active esters (RAEs) to isoquinolines has been developed. A variety prochiral α-aminoalkyl radicals generated from RAEs were successfully introduced on isoquinolines, providing range valuable α-isoquinoline-substituted secondary amines in high yields good excellent enantioselectivities.

Language: Английский

Citations

134
Photocatalytic Generation of Aminium Radical Cations for C–N Bond Formation DOI
Jacob M. Ganley, Philip R. D. Murray, Robert R. Knowles

et al.

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(20), P. 11712 - 11738

Published: Sept. 11, 2020

Aminium radical cations have been extensively studied as electrophilic aminating species that readily participate in C–N bond forming processes with alkenes and arenes. However, their utility synthesis has limited, generation required unstable, reactive starting materials harsh reaction conditions. Visible-light photoredox catalysis emerged a platform for the mild production of aminium from either unfunctionalized or N-functionalized amines. This Perspective covers recent synthetic methods rely on photocatalytic formation, specifically context alkene hydroamination, arene C–H amination, mesolytic cleavage alkoxyamines.

Language: Английский

Citations

133
Mechanistische Studien in der Photokatalyse DOI Open Access
Luca Buzzetti, Giacomo E. M. Crisenza, Paolo Melchiorre

et al.

Angewandte Chemie, Journal Year: 2018, Volume and Issue: 131(12), P. 3768 - 3786

Published: Oct. 19, 2018

Abstract Die sich rasant entwickelnden Felder der Photo‐ und Photoredoxkatalyse bieten neue Gelegenheiten, das Potential synthetisch‐organischen Chemie zu erweitern. Fortschritte bei photokatalytischen Prozessen haben bisher vor allem aus empirischen Entdeckungen Suche nach neuen Reaktionen ergeben. allgemeine Wahrnehmung jedoch ist, dass die Photokatalyse in eine reifere Phase eintritt, Kombination experimenteller mechanistischer Studien Vorreiterrolle für weitere Innovationen spielt. Dieser Aufsatz beschreibt mechanistischen Schlüsselstudien, Entwicklung photochemischer Prozesse Betracht gezogen werden sollten, sowie geeignetsten verfügbaren Techniken zur Gewinnung relevanter Informationen. Diskussion verweist auf ausgewählte Fallstudien, um zeigen, wie mechanistische Untersuchungen instrumentelle Rolle Entdeckung synthetisch nützlicher, photokatalytischer Transformationen spielen können.

Citations

120
Discovery and Elucidation of Counteranion Dependence in Photoredox Catalysis DOI
Elliot P. Farney, Steven J. Chapman, Wesley B. Swords

et al.

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(15), P. 6385 - 6391

Published: March 21, 2019

Over the past decade, there has been a renewed interest in use of transition metal polypyridyl complexes as photoredox catalysts for variety innovative synthetic applications. Many derivatives these are known, and effect ligand modifications on their efficacy subject extensive, systematic investigation. However, influence photocatalyst counteranion received little attention, despite fact that generally cationic nature. Herein, we demonstrate effects exert surprising, dramatic impact rate representative photocatalytic radical cation Diels–Alder reaction. A detailed analysis reveals identity impacts multiple aspects reaction mechanism. Most notably, photocatalysts with more noncoordinating counteranions yield powerful triplet excited state oxidant longer chain length. It is proposed this arises from Coulombic ion-pairing interactions between both catalyst intermediate, respectively. The comparatively slower coordinating can be rescued by using hydrogen-bonding anion binders attenuate deleterious interactions. These results importance variable design optimization transformations suggest novel strategy organic reactions class photocatalysts.

Language: Английский

Citations

116