Helical Carbenium Ion: A Versatile Organic Photoredox Catalyst for Red-Light-Mediated Reactions

2020 ◽  
Vol 142 (28) ◽  
pp. 12056-12061 ◽  
Author(s):  
Liangyong Mei ◽  
José M. Veleta ◽  
Thomas L. Gianetti
Keyword(s):  
Red Light ◽  
Carbenium Ion

scholarly journals Helical Carbenium Ion: A Versatile Organic Photoredox Catalyst in Red-Light-Mediated Reactions

2020 ◽  
Author(s):  
Liangyong Mei ◽  
Jose M Veleta ◽  
thomas Gianetti
Keyword(s):  
Transition Metal ◽  
Health Risk ◽  
Penetration Depth ◽  
Red Light ◽  
Radical Addition ◽  
Low Energy ◽  
Arylboronic Acids ◽  
High Penetration ◽  
Atom Transfer Radical Addition ◽  
Carbenium Ion

<div><p><a></a><a></a><a></a><a>Red light has the advantages of low energy, less health risk and high penetration depth through various media. Herein, </a>a <a>helical carbenium ion (</a><i>N,N’</i>-di-<i>n</i>-propyl-1,13-dimethoxyquinacridinium (<i><sup>n</sup></i>Pr-DMQA<sup>+</sup>) tetrafluoroborate) has been used as an organic photoredox catalyst for photoreductions and photooxidations in the presence of red light (λ<sub>max</sub> = 640 nm). It has catalyzed red-light-mediated dual transition-metal/photoredox-catalyzed C-H arylation and intermolecular atom transfer radical addition through oxidative quenching, affording products in 57-93% yields. Moreover, its potential in photooxidation catalysis has also been demonstrated by successful applications in red-light-induced aerobic oxidative hydroxylation of arylboronic acids and benzylic C(sp<sup>3</sup>)-H oxygenation through reductive quenching, delivering products in up to 92% yield. Thus, a versatile organic photoredox catalyst (helical carbenium ion)<b> </b>for red-light-mediated photoredox reactions has been developed.</p></div>

scholarly journals Helical Carbenium Ion: A Versatile Organic Photoredox Catalyst in Red-Light-Mediated Reactions

2020 ◽  
Author(s):  
Liangyong Mei ◽  
Jose M Veleta ◽  
thomas Gianetti
Keyword(s):  
Transition Metal ◽  
Health Risk ◽  
Penetration Depth ◽  
Red Light ◽  
Radical Addition ◽  
Low Energy ◽  
Arylboronic Acids ◽  
High Penetration ◽  
Atom Transfer Radical Addition ◽  
Carbenium Ion

<div><p><a></a><a></a><a></a><a>Red light has the advantages of low energy, less health risk and high penetration depth through various media. Herein, </a>a <a>helical carbenium ion (</a><i>N,N’</i>-di-<i>n</i>-propyl-1,13-dimethoxyquinacridinium (<i><sup>n</sup></i>Pr-DMQA<sup>+</sup>) tetrafluoroborate) has been used as an organic photoredox catalyst for photoreductions and photooxidations in the presence of red light (λ<sub>max</sub> = 640 nm). It has catalyzed red-light-mediated dual transition-metal/photoredox-catalyzed C-H arylation and intermolecular atom transfer radical addition through oxidative quenching, affording products in 57-93% yields. Moreover, its potential in photooxidation catalysis has also been demonstrated by successful applications in red-light-induced aerobic oxidative hydroxylation of arylboronic acids and benzylic C(sp<sup>3</sup>)-H oxygenation through reductive quenching, delivering products in up to 92% yield. Thus, a versatile organic photoredox catalyst (helical carbenium ion)<b> </b>for red-light-mediated photoredox reactions has been developed.</p></div>

Helical Carbenium Ion-Based Organic Photoredox Catalyst: A Versatile and Sustainable Option in Red-Light-Induced Reactions

Synlett ◽  
2020 ◽  
Author(s):  
Thomas Gianetti ◽  
Liangyong Mei
Keyword(s):  
Transition Metal ◽  
Catalytic System ◽  
Red Light ◽  
Low Energy ◽  
Atom Transfer ◽  
Arylboronic Acids ◽  
Carbenium Ion ◽  
Catalytic Cycles

AbstractThe development of a sustainable catalytic system for red-light-induced photocatalysis is presented. The catalytic system consists of a helical carbenium ion-based organic photoredox catalyst (PC) that is capable of using low-energy red light (λmax = 640 nm) for both photooxidations and photoreductions. Its successful applications in the aerobic oxidative hydroxylation of arylboronic acids and in the oxidation of benzylic C(sp3)–H bonds (reductive quenching), as well as in dual transition-metal/organocatalyzed C–H arylations and intermolecular atom-transfer radical additions (oxidative quenching) provide further support for its role as a versatile and efficient organic PC.1 Introduction2 Red-Light-Induced Photocatalysis3 Properties of N,N′-Dipropyl-1,13-dimethoxyquinacridinium Tetrafluoroborate4 Two Proposed Representative Catalytic Cycles of [ n Pr-DMQA+][BF4 –]5 Applications of [ n Pr-DMQA+][BF4 –] in Red-Light-Induced Photocatalysis6 Conclusion

Postnatal growth rate and gonadal development in circadian tau mutant hamsters reared in constant dim red light

Reproduction ◽  
2000 ◽  
pp. 327-330 ◽  
Author(s):  
RJ Lucas ◽  
JA Stirland ◽  
YN Mohammad ◽  
AS Loudon
Keyword(s):  
Time Course ◽  
Red Light ◽  
Somatic Growth ◽  
Postnatal Growth ◽  
Gonadal Development ◽  
Testicular Development ◽  
Wild Type ◽  
Similar Time ◽  
Syrian Hamsters ◽  
Body Weights

The role of the circadian clock in the reproductive development of Syrian hamsters (Mesocricetus auratus was examined in wild type and circadian tau mutant hamsters reared from birth to 26 weeks of age under constant dim red light. Testis diameter and body weights were determined at weekly intervals in male hamsters from 4 weeks of age. In both genotypes, testicular development, subsequent regression and recrudescence exhibited a similar time course. The age at which animals displayed reproductive photosensitivity, as exhibited by testicular regression, was unrelated to circadian genotype (mean +/- SEM: 54 +/- 3 days for wild type and 59 +/- 5 days for tau mutants). In contrast, our studies revealed a significant impact of the mutation on somatic growth, such that tau mutants weighed 18% less than wild types at the end of the experiment. Our study reveals that the juvenile onset of reproductive photoperiodism in Syrian hamsters is not timed by the circadian system.

Inhibition of Various Steps in the Replication Cycle of Vesicular Stomatitis Virus Contributes to Its Photoinactivation by AlPcS4 or Pc4 and Red Light

1999 ◽  
Vol 69 (3) ◽  
pp. 353 ◽  
Author(s):  
Anne C. E. Moor ◽  
Angeline E. Wagenaars-van Gompel ◽  
Ralph C. A. Hermanns ◽  
Jannes van der Meulen ◽  
Jolanda Smit ◽  
...  
Keyword(s):  
Vesicular Stomatitis Virus ◽  
Red Light ◽  
Replication Cycle ◽  
Vesicular Stomatitis
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