ChemInform Abstract: Novel Regioselective Aromatic Chlorination via Catalytic Thiourea Activation of N‐Chlorosuccinimide.

Abstract A metal and acid-free electrophilic aromatic chlorination methodology involving catalytic thiourea activation of N-chlorosuccinimide (NCS) is reported herein. Moderate yields and regioselectivities of chlorinated aromatics were obtained using a combination of 1.05–1.15 equiv of NCS and 5 mol % of thiourea at room temperature in acetonitrile. A halogen bond between the sulfur atom of thiourea and the sigma-hole of the NCS chlorine atom is thought to enhance the electrophilic activity of the chlorine of NCS.