Highly Chemoselective Catalytic Photooxidations by Using Solvent as a Sacrificial Electron Acceptor

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F22%3A00562683" target="_blank" >RIV/61388963:_____/22:00562683 - isvavai.cz</a>

Alternative codes found

RIV/60461373:22310/22:43925220 RIV/60461373:22810/22:43925220

Result on the web

<a href="https://doi.org/10.1002/chem.202202487" target="_blank" >https://doi.org/10.1002/chem.202202487</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/chem.202202487" target="_blank" >10.1002/chem.202202487</a>

Result language

angličtina

Original language name

Highly Chemoselective Catalytic Photooxidations by Using Solvent as a Sacrificial Electron Acceptor

Original language description

Catalyst recovery is an integral part of photoredox catalysis. It is often solved by adding another component-a sacrificial agent-whose role is to convert the catalyst back into its original oxidation state. However, an additive may cause a side reaction thus decreasing the selectivity and overall efficiency. Herein, we present a novel approach towards chemoselective photooxidation reactions based on suitable solvent-acetonitrile acting simultaneously as an electron acceptor for catalyst recovery, and on anaerobic conditions. This is allowed by the unique properties of the catalyst, 7,8-dimethoxy-3-methyl-5-phenyl-5-deazaflavinium chloride existing in both strongly oxidizing and reducing forms, whose strength is increased by excitation with visible light. Usefulness of this system is demonstrated in chemoselective dehydrogenations of 4-methoxy- and 4-chlorobenzyl alcohols to aldehydes without over-oxidation to benzoic acids achieving yields up to 70 %. 4-Substituted 1-phenylethanols were oxidized to ketones with yields 80-100 % and, moreover, with yields 31-98 % in the presence of benzylic methyl group, diphenylmethane or thioanisole which are readily oxidized in the presence of oxygen but these were untouched with our system. Mechanistic studies based on UV-Vis spectro-electrochemistry, EPR and time-resolved spectroscopy measurements showed that the process involving an electron release from an excited deazaflavin radical to acetonitrile under formation of solvated electron is crucial for the catalyst recovery.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10401 - Organic chemistry

Project

<a href="/en/project/GA19-09064S" target="_blank" >GA19-09064S: Organic photoredox catalysis in reductive transformations: new area for flavin derivatives</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Chemistry - A European Journal

ISSN

0947-6539

e-ISSN

1521-3765

Volume of the periodical

28

Issue of the periodical within the volume

67

Country of publishing house

DE - GERMANY

Number of pages

8

Pages from-to

e202202487

UT code for WoS article

000863954700001

EID of the result in the Scopus database

2-s2.0-85139418870