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

Abstract

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. ©2005 Sociedade Brasileira de Química.