N-heterocyclic carbene copper(I) complex-catalyzed direct C–H thiolation of benzothiazoles

N-heterocyclic carbene (NHC) copper(I) complexes based on imidazol-2-ylidene and 1,2,3-triazol-5-ylidene catalyzed the direct C–H thiolation of benzothiazoles and benzoxazoles with aryl and alkyl thiols to give 2-aryl and 2-alkylthiobenzothiazoles in moderate-to-good yields. The NHC copper(I) complex [(IPr)CuI] was the most effective catalyst for the reaction among the NHC–Cu(I) complexes examined in this study.