TY  - JOUR
A1  - Bauch, Marcel
A1  - Krtitschka, Angela
A1  - Linker, Torsten
T1  - Photooxygenation of oxygen-substituted naphthalenes
JF  - Journal of physical organic chemistry
N2  - The reaction of oxygen-substituted naphthalenes with singlet oxygen (O-1(2)) has been investigated, and labile endoperoxides have been isolated and characterized at -78 degrees C for the first time. Low-temperature kinetics by UV spectroscopy revealed that alkoxy and silyloxy substituents remarkably increase the rate of photooxygenations compared to 1,4-dimethylnaphthalene, whereas acyloxy-substituted acenes are inert towards O-1(2). The reactivities nicely correlate with HOMO energies and free activation energies, which we determined by density functional theory calculations. The lability of the isolated endoperoxides is due to their very fast back reaction to the corresponding naphthalenes even at -20 degrees C under release of O-1(2), making them to superior sources of this reactive species under very mild conditions. Finally, a carbohydrate-substituted naphthalene has been synthesized, which reacts reversibly with O-1(2) and might be applied for enantioselective oxidations in future work.
KW  - kinetics
KW  - labile peroxides
KW  - low-temperature experiments
KW  - naphthalenes
KW  - singlet oxygen
Y1  - 2017
U6  - https://doi.org/10.1002/poc.3734
SN  - 0894-3230
SN  - 1099-1395
VL  - 30
SP  - 6803
EP  - 6813
PB  - Wiley
CY  - Hoboken
ER  -