O2-Mediated Photocatalytic Functionalization of Organic Compounds: Recent Advances Towards Greener Synthetic Routes

Eco-friendly standards require organic synthetic protocols able to combine a low environmental impact with an economical convenience. The aerobic selective oxidation of organic compounds promoted by visible light radiation (including ambient sunlight) is candidate to become one of the most important, cheapest and greenest tools to transform raw materials into more complex molecules. Most of organic photochemical processes reported in the literature in the last century are promoted by high-energy ultraviolet radiation, this limiting the potential benefits of the proposed approaches. Nevertheless, in the last decade several inorganic, organometallic and organic photocatalysts (doped semiconductors, transition metal complexes, organic molecules and ions) have been developed, which are able to adsorb in the visible spectrum. Herein we provide a concise overview of the most significant and recent examples in which these photocatalysts are able to promote the functionalization of organic compounds via selective photooxidation in a molecular oxygen atmosphere.