REACTION OF POTASSIUM SUPEROXIDE WITH PHENOXY RADICALS. ON THE MECHANISM OF BASE-CATALYZED OXYGENATION OF PHENOLS

Abstract
Superoxide ion (O2) hes been found not to couple with 2,6-di-tert-butylphenoxy radicals but to reduce the radicals giving rise to the corresponding phenolates. Molecular oxygen attacks predominantly the para position of the phenoxy radicals and the regioselectivity is not affected by the nature of the reaction medium. A new mechanism involving an ionic process for the base-catalyzed oxygenation of 2,6-di-tert-butylphenols is proposed.
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