Visible-Light-Induced Cleavage of C-S Bonds in Thioacetals and Thioketals with Iodine as a Photocatalyst

A protocol for a visible-light-induced cleavage of thioacetals and thioketals using molecular iodine as a photocatalyst in combination with oxygen as the terminal oxidant is reported. The reaction proceeds with low catalyst loadings and high chemical yields while the most commonly used N- and O-protecting groups remain untouched in this transformation. Further investigation showed that the reaction also permits the synthesis of unsymmetrical disulfides by cleavage of unsymmetrical thioacetals.