Dabco-catalysed selective chlorination of aromatics

In this report, we present a highly efficient aromatic chlorination that is catalysed by 1,4-diazabicyclo[2.2.2]octane (DABCO) with N-chlorosuccinimide (NCS) as the chloro source. The mild conditions, easy-availability and stability of the catalyst and reagents, as well as good functional-group tolerance, showed the approach to be a versatile protocol for the late-stage aromatic chlorination of complex natural products and drugs. A plausible catalytic mechanism was constructed through comprehensive computational studies.