Thianthrenation‐Enabled Cyanomethylation of (Hetero)Arenes With 2‐Azidoallyl Alcohols via Electron Donor–Acceptor Complex Photoactivation

A catalyst‐free approach for the cyanomethylation reaction of thianthrenium salts with 2‐azidoallyl alcohols via electron donor–acceptor complex photoactivation using DABCO as the electron donor is herein described. A diverse range of (hetero)arylacetonitriles was synthesized in moderate to good yields. This approach is compatible with a variety of functional groups and enables late‐stage functionalization of bioactive molecules bearing an arene moiety. Further synthetic transformations of the products and preliminary mechanistic studies are also presented.