Journal of the American Chemical Society
ARTICLE
relationship is observed, with a F value of opposite sign and
similar magnitude (ꢀ0.60). Accordingly, upon modification of
the more electron-donating portion of the ligand, greater elec-
tron-donating ability leads to increased rate of reaction. This
further supports coordination of the anionic tert-butylperoxide
trans to the more donating portion of the ligand (i.e., the
oxazoline). Should the coordination environment exist as it is
depicted in N, then the trends in the ligand Hammett studies
would be expected to be opposite of what is observed.
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’ CONCLUSION
In conclusion, the proposed mechanism for the TBHP-
mediated Wacker-type oxidation of olefins was supported by
initial rate kinetics. Saturation in TBHP is in concert with syn-
peroxypalladation by tert-butylperoxide, which agrees with the
analogous mechanism proposed by Mimoun and co-workers.
The electrophilicity of the catalyst was found to have a direct
influence on reactivity, as indicated by a linear free energy
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counterions’ conjugate acids. Product inhibition was observed;
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’ ASSOCIATED CONTENT
S
Supporting Information. Experimental procedures, kinetic
b
data, and full spectroscopic data for all new compounds. This material
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’ AUTHOR INFORMATION
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Corresponding Author
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Angew. Chem., Int. Ed. 2010, 49, 7312–7315.
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’ ACKNOWLEDGMENT
This work was supported by the National Institutes of Health
(NIGMS RO1 GM63540).
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