Copper-Catalyzed Thiolation of Terminal Alkynes with N-Thiosuccinimides to Access Alkynyl Sulfides

An efficient copper-catalyzed thiolation of terminal alkynes with N-thiosuccinimides was developed. The reaction demonstrated an expanded substrate scope and produced various alkynyl sulfides in moderate to good yields. Gram-scale synthesis and further transformations confirmed the synthetic utility of this methodology. Preliminary mechanistic studies revealed that a Cu(I)/Cu(III) catalytic cycle was probably involved in the process of alkynylthiolation.