CuI/Oxalic Diamide-Catalyzed Cross-Coupling of Thiols with Aryl Bromides and Chlorides.

We report a general copper-catalyzed cross-coupling of thiols with aryl halides by using N-aryl-N'-alkyl oxalic diamide (L3) or N,N'-dialkyl oxalic diamide (L5) as the ligand. Both aryl and alkyl thiols can be coupled with unactivated aryl bromides and chlorides to give the desired products in good yields. Furthermore, this system features a broad substrate scope and good tolerance of functional groups. Importantly, the oxalic diamides are stable and can be prepared easily from commercially available and cheap starting materials.