Zn(Pro) 2-promoted CuI-catalyzed synthesis of diphenyl sulfide derivations in ionic liquid

We report a mild, palladium-free synthetic protocol for the cross-coupling reaction of aryl chlorides and thiols under the assistance of Zn complexes of proline and CuI, with K₂CO₃ as the base, performed at 110 °C in ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (Bmim]BF ₄). This protocol is particularly noteworthy given its experimental simplicity, high generality, and the exceptional level of functional group tolerations and low cost of the catalyst system.