Carbene catalyzed C(sp3)–Cl activation of chlorinated solvents for benzyne chlorination

Abstract

An N-heterocyclic carbene (NHC) organocatalyzed benzyne chlorination reaction is reported. Chlorinated solvents, usually shown to be inert, are widely used in either carbene chemistry or benzyne chemistry. However, the combination of carbene and benzyne showed remarkable C–Cl cleavage reactivity towards chlorinated solvents. Several common solvents such as tetrachloromethane, chloroform (or CDCl₃), dichloromethane, 1,2-dichloroethane, etc. have been successfully activated by NHC and reacted with benzynes derived from the hexa-dehydro-Diels–Alder (HDDA) reaction to give dichlorination or hydrochlorination products.