Substrate-promoted ligand-free CuI catalyzed S-arylation of 2-mercaptobenzothiazoles with aryl iodides in water

A green and efficient method has been developed for the cross-coupling of 2-mercaptobenzothiazoles with aryl iodides in water. The reactions proceeded smoothly under ligand-free conditions in the presence of TBAB to give the corresponding products in good yields. The protocol showed good tolerance toward a variety of functional groups. A substrate-promoted mechanism for this catalytic reaction has been proposed.