Electrochemical aerobic Wacker-type oxygenation of triaryl substituted alkenes to 1,2,2-triarylethanones

An effective synthetic approach for various 1,2,2-triarylethanones from triaryl substituted alkenes has been developed via an electrochemical Wacker-type oxygenation with O 2 as the sole oxygen source. It presents the first instance of the Wacker-type oxidation expanding its substrate scope to trisubstituted alkenes. The approach is transition-metal-free, compatible with various functional groups, and can be carried out under mild conditions resulting in satisfactory yields. Mechanistic experiments suggest the C&z.dbd;O bond formation occurs through reactions between cationic carbon species and the superoxide radical, which involves the 1,2-shift of the electron-rich substituent. An electrochemical oxygenation approach to obtain 1,2,2-triarylethanones represents the first expansion of Wacker-type oxidation substrate scope to triaryl-substituted alkenes.