Study of photo-oxidation with molecular oxygen

Abstract

Molecular oxygen has recently received much attention, since it is photosynthesized by plants and is an effective oxidant of larger atom efficiency than that of other oxidants. In the course of our study of photo-oxidation, we have found that alcohols and methyl group at aromatic nucleus were oxidized directly to the corresponding carboxylic acids in the presence of catalytic bromine sources, such as lithium bromide, bromine, and hydrobromic acid, in an oxygen atmosphere under irradiation of UV or VIS. This new oxidation reaction is interesting in keeping with the notion of Green Chemistry due to non-use of heavy metals, waste reduction, use of molecular oxygen, and inexpensive acquisition of reagents. Herein, we report our study on the generality of this aerobic photo-oxidation in detail.