Visible light photocatalysis with CBr4: a highly selective aerobic photooxidation of methylarenes to aldehydes

A metal-free, operationally simple and efficient means of aerobic photooxidation of methylarenes to aromatic aldehydes at room temperature employing visible light photocatalysis with CBr4 is reported. The reaction is highly selective as it proceeds without any over oxidation to carboxylic acids. The utilisation of visible light and molecular oxygen is inexpensive, readily available, non-toxic and the sustainable reagents make the protocol compatible with green chemistry demands. A plausible mechanism for the formation of aldehydes from methylarenes is also provided.