Trichloroisocyanuric acid in H2SO4: an efficient superelectrophilic reagent for chlorination of isatin and benzene derivatives

+ao anel aromatico mais eficientemente do que o TICA devido ao alivio da repulsao carga-carga. Trichloroisocyanuric acid (TICA) in H 2 SO 4 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.