Site-selective aromatic C–H λ³-iodanation with a cyclic iodine(<scp>iii</scp>) electrophile in solution and solid phases

Abstract

An efficient and site-selective aromatic C-H λ³-iodanation reaction is achieved using benziodoxole triflate (BXT) as an electrophile under room temperature conditions. The reaction tolerates a variety of electron-rich arenes and heteroarenes to afford the corresponding arylbenziodoxoles in moderate to good yields. The reaction can also be performed mechanochemically by grinding a mixture of solid arenes and BXT under solvent-free conditions. The arylbenziodoxoles can be used for various C-C and C-heteroatom bond formations, and are also amenable to further modification by electrophilic halogenation. DFT calculations suggested that the present reaction proceeds <i>via</i> a concerted λ³-iodanation-deprotonation transition state, where the triflate anion acts as an internal base.