Trichloroisocyanuric acid (TICA) in H2SO4 is an efficient reagent for regioselective chlorination of isatin at the 5-position and deactivated aromatic compounds, such as nitrobenzene. DFT calculations suggest formation of a superelectrophilic polyprotonated species that can transfer Cl+ to the aromatic ring more efficiently than TICA due to charge-charge repulsion relief.
trichloroisocyanuric acid; chlorination; superelectrophile; aromatic compounds; DFT calculations
