Heterogeneously catalyzed direct C-H thiolation of heteroarenes.

The first general methodology for the direct thiolation of electron-rich heteroarenes was developed by employing Pd/Al2 O3 , a recoverable and commercially available heterogeneous catalyst, and CuCl2 . This method represents an operationally simple approach for the synthesis of these valuable compounds. Preliminary mechanistic studies indicate a heterogeneous catalytic system, in which both metals play a complementary role in the formation of the thiolated products.