TY  - JOUR
A1  - Fudickar, Werner
A1  - Linker, Torsten
T1  - Release of Singlet Oxygen from Organic Peroxides under Mild Conditions
JF  - ChemPhotoChem
N2  - Singlet oxygen can be released in the dark in nearly quantitative yield from endoperoxides of naphthalenes, anthracenes and pyridones as an alternative to its generation by photosensitization. Recently, new donor systems have been designed which operate at very low temperatures but which are prepared from their parent forms at acceptable rates. Enhancement of the reactivity of donors is conveniently achieved by the design of the substitution pattern or through the use of plasmonic heating of nanoparticle-bound donors. The most important aim of these donor molecules is to transfer singlet oxygen in a controlled and directed manner to a target. Low temperatures and the linking between donors and acceptors reduce the random walk of oxygen and may force an attack at the desired position. By using chiral donor systems, new stereocenters might be introduced into prochiral acceptors.
KW  - donor-acceptor systems
KW  - oxygenation
KW  - peroxides
KW  - polycycles
KW  - retro reactions
Y1  - 2018
U6  - https://doi.org/10.1002/cptc.201700235
SN  - 2367-0932
VL  - 2
IS  - 7
SP  - 548
EP  - 558
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Fudickar, Werner
A1  - Linker, Torsten
T1  - Release of Singlet Oxygen from Aromatic Endoperoxides by Chemical Triggers
JF  - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition
N2  - The generation of reactive singlet oxygen under mild conditions is of current interest in chemistry, biology, and medicine. We were able to release oxygen from dipyridylanthracene endoperoxides (EPOs) by using a simple chemical trigger at low temperature. Protonation and methylation of such EPOs strongly accelerated these reactions. Furthermore, the methyl pyridinium derivatives are water soluble and therefore serve as oxygen carriers in aqueous media. Methylation of the EPO of the ortho isomer affords the parent form directly without increasing the temperature under very mild conditions. This exceptional behavior is ascribed to the close contact between the nitrogen atom and the peroxo group. Singlet oxygen is released upon this reaction, and can be used to oxygenate an acceptor such as tetramethylethylene in the dark with no heating. Thus, a new chemical source of singlet oxygen has been found, which is triggered by a simple stimulus.
KW  - anthracenes
KW  - donor-acceptor systems
KW  - mild reaction conditions
KW  - selective oxidations
KW  - singlet oxygen
Y1  - 2018
U6  - https://doi.org/10.1002/anie.201806881
SN  - 1433-7851
SN  - 1521-3773
VL  - 57
IS  - 39
SP  - 12971
EP  - 12975
PB  - Wiley-VCH
CY  - Weinheim
ER  -