Bi4O5Br2 catalyzed selective oxidative of C=C double bonds to ketones with molecular oxygen under visible-light irradiation

A green, eco-friendly, safe method for the oxidative cleavage of C=C double bonds to form ketone via photocatalysis under a bismuth-rich Bi4O5Br2 semiconductor photosensitizer, O2 as the oxygen source and H2O as the main solvent have been reported. Compared with homogeneous catalyst, The catalyst can be used for 4 times and without a significant reduction in activity. Through the EPR experiment and mechanism verification experiments, superoxide radical or photogenerated electrons and holes played important roles in the oxidative cleavage of C=C double bonds.