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

Abstract

An effective synthetic approach for various 1,2,2-triarylethanones from triaryl substituted alkenes has been developed via an electrochemical Wacker-type oxygenation with O₂ 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 CO bond formation occurs through reactions between cationic carbon species and the superoxide radical, which involves the 1,2-shift of the electron-rich substituent.