Catalytic oxidative 1,2-shift in 1,1'-disubstituted olefins using arene(iodo)sulfonic acid as the precatalyst and oxone as the oxidant.

An efficient, catalytic hypervalent iodine-mediated oxidative 1,2-shift of 1,1'-disubstituted olefins is described. This methodology provides concise access to homobenzylic ketones with electron-donating substituents. In the case of cyclic systems, this transformation results in ring-expanded β-benzocycloalkanones, which are useful for further elaboration.