Abstract
| Original language | English |
|---|---|
| Journal | Journal of the American Chemical Society |
| DOIs | |
| Publication status | Published - 29 Aug 2017 |
Fingerprint
Cite this
}
Mechanism of Catalytic Oxidation of Styrenes with Hydrogen Peroxide in the Presence of Cationic Palladium(II) Complexes. / Walker, Katherine ; Dornan, Laura; Zare, Richard ; Waymouth, Robert ; Muldoon, Mark.
In: Journal of the American Chemical Society, 29.08.2017.Research output: Contribution to journal › Article
TY - JOUR
T1 - Mechanism of Catalytic Oxidation of Styrenes with Hydrogen Peroxide in the Presence of Cationic Palladium(II) Complexes
AU - Walker, Katherine
AU - Dornan, Laura
AU - Zare, Richard
AU - Waymouth, Robert
AU - Muldoon, Mark
PY - 2017/8/29
Y1 - 2017/8/29
N2 - Kinetic studies, isotope labeling, and in situ high-resolution mass spectrometry are used to elucidate the mechanism for the catalytic oxidation of styrenes using aqueous hydrogen peroxide (H2O2) and the cationic palladium(II) compound, [(PBO)Pd(NCMe)2][OTf]2 (PBO = 2-(pyridin-2-yl)benzoxazole). Previous studies have shown that this reaction yields acetophenones with high selectivity. We find that H2O2 binds to Pd(II) followed by styrene binding to generate a Pd-alkylperoxide that liberates acetophenone by at least two competitive processes, one of which involves a palladium enolate intermediate that has not been previously observed in olefin oxidation reactions. We suggest that acetophenone is formed from the palladium enolate intermediate by protonation from H2O2. We replaced hydrogen peroxide with t-butyl hydroperoxide and found that, although the palladium enolate intermediate was observed, it was not on the major product-generating pathway, indicating that the form of the oxidant plays a key role in the reaction mechanism.
AB - Kinetic studies, isotope labeling, and in situ high-resolution mass spectrometry are used to elucidate the mechanism for the catalytic oxidation of styrenes using aqueous hydrogen peroxide (H2O2) and the cationic palladium(II) compound, [(PBO)Pd(NCMe)2][OTf]2 (PBO = 2-(pyridin-2-yl)benzoxazole). Previous studies have shown that this reaction yields acetophenones with high selectivity. We find that H2O2 binds to Pd(II) followed by styrene binding to generate a Pd-alkylperoxide that liberates acetophenone by at least two competitive processes, one of which involves a palladium enolate intermediate that has not been previously observed in olefin oxidation reactions. We suggest that acetophenone is formed from the palladium enolate intermediate by protonation from H2O2. We replaced hydrogen peroxide with t-butyl hydroperoxide and found that, although the palladium enolate intermediate was observed, it was not on the major product-generating pathway, indicating that the form of the oxidant plays a key role in the reaction mechanism.
UR - http://pubs.acs.org/doi/abs/10.1021/jacs.7b05413
U2 - 10.1021/jacs.7b05413
DO - 10.1021/jacs.7b05413
M3 - Article
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
ER -