Visible Light Mediated Chemoselective Hydroxylation of Benzylic Methylenes.

We have developed a metal-free photocatalytic selective hydroxylation of benzylic methylenes to secondary alcohols. This approach utilizes low-cost eosin Y as photocatalyst, O2 as green oxidant, and inexpensive triethylamine as inhibitor for overoxidation. The mild reaction conditions enable the production of secondary alcohols with 56-95% yields, making it a promising and environmental-friendly method for the synthesis of secondary alcohols from benzylic methylenes.