Iodine-mediated oxidative triple functionalization of indolines with azoles and diazonium salts

We report an innovative synthetic strategy for the generation of polysubstituted indoles from indolines, aryldiazonium salts, and azoles. The methodology encompasses an electrophilic substitution reaction affording C5-indoline intermediates which undergo an iodine-mediated oxidative transformation coupled with C-H functionalization to yield the indole derivatives. A tandem oxidative multi-functionalization strategy for the synthesis of the C2,3,5-trifunctional indoles from indolines, aryldiazonium salts and azoles was developed.