Photoelectrocatalytic Arene C-H Amination

Photoelectrochemical cells are widely studied for solar energy conversion. However, they have rarely been used for the synthesis of high added-value organic molecules. Here we describe a strategy to use hematite, an abundant and robust photoanode, for non-directed arene C-H amination. Under illumination the photo generated holes in hematite oxidizes electron-rich arenes to radical cations which further react with azoles to give nitrogen heterocycles of medicinal interest. Unusual ortho-selectivity has been achieved probably due to a hydrogen bonding interaction between the substrates and the hexafluoroisopropanol co-solvent. The method exhibits broad scope and is successfully applied for the late-stage functionalization of several pharmaceutical molecules.