Transition metal free oxygenation of 8-aminoquinoline amides in water
The oxygenation of 8-aminoquinoline amides by benzoyl peroxide at the C5 position in water is developed in the absence of a transition metal catalyst, affording the desired products in moderate to good yields of up to 88%. Mechanism studies reveal that the reaction would involve a radical process.
Behavior of naphthoyloxyl and methoxynaphthoyloxyl radicals generated from the photocleavage of dinaphthoyl peroxides and 1-(naphthoyloxy)-2-pyridones
1-Naphthoyloxyl and 2-naphthoyloxyl radicals were generated from photocleavage of dinaphthoyl peroxides and 1-(naphthoyloxy)-2-pyridones in acetonitrile. The difference in product distribution between the precursors is ascribed to the contribution of the two-bond cleavage in the peroxide decomposition in the singlet state. A series of methoxynaphthoyloxyl radicals were also generated from the corresponding (methoxynaphthoyloxy)pyridones and their behavior was compared with that of unsubstituted naphthoyloxyl radicals. The introduction of a methoxy group in the naphthalene ring stabilizes the naphthoyloxyl radicals to prevent their decarboxylation completely and reduces remarkably their reactivities in the addition to olefins and hydrogen-atom abstraction. The structure of the naphthoyloxyl radicals was discussed on the basis of their absorption spectra and MO calculations.