Bromothiolation of Internal Alkynes
Nitric Acid Promoted Metal-Free Bromothiolation of Internal Alkynes with Hydrobromic Acid and Disulfides: H. Sun, X.-C. Huang, Z.-X. Yao, H. Su
Synlett 2022, DOI: 10.1055/s-0040-1719934
β-Haloalkenyl sulfides are versatile coupling partners for the synthesis of alkenes and alkynyl sulfides via nucleophilic substitutions and transition-metal-catalyzed cross-coupling reactions. In turn, the resulting alkenyl sulfides are very useful building blocks and key components in the synthesis of a range of natural products and biologically active compounds. Recently, the group of Xiao-Cheng Huang from the Guangxi University of Science and Technology (Liuzhou, P. R. of China) described a new Z-stereospecific entry to β-bromoalkenyl sulfides promoted by nitric acid.
Xiao-Cheng Huang said: "We have developed a mild and cheap bromothiolation of internal alkynes with hydrobromic acid and disulfides. The methodology stereoselectively constructs a series of syn-β-bromoalkenyl sulfides in moderate to good yields, and both sulfide groups of the disulfide reagent were used. Furthermore, a gram-scale experiment revealed the potential applicative value of this protocol."