Alkynylthioimidazolium Salts: Efficient Reagents for the Synthesis of Alkynyl Sulfides by Electrophilic Thioalkynylation.

The efficient synthesis of a series of alkynylthioimidazolium salts through reaction of organozinc compounds with dibromo(imidazolium)sulfuranes is reported. Addition of Grignard reagents to these new species provided a highly modular, clean, and scalable access to a broad variety of alkynyl sulfides in good-to-excellent yields. The utility of this protocol was showcased by the preparation of alkynyl sulfides, which are particularly difficult to obtain or simply unavailable through the existing methodologies. In addition, the synthetic method was extended to the preparation of alkynyl selenides.