This work describes an efficient and stereoselective method for the hydrothiolation
and -selenation of buta-1,3-diyne derivatives using diaryl disulfides or diselenides,
respectively. In the presence of rongalite (HOCH2SO2Na) and potassium carbonate, buta-1,3-diynes undergo stereoselective addition of the
thiolate or selenide anion generated in situ from diaryl disulfides or diselenides
to afford the corresponding (Z)-1-sulfanyl- or (Z)-1-selanylalk-1-en-3-yne derivatives, respectively. The reaction of buta-1,3-diynes
with diaryl disulfides or diselenides at higher temperature (70 °C) gave a mixture
of monothiolation/selenation and bisthiolation/selenation products in moderate to
good yields.
Key words
hydrochalcogenation - buta-1,3-diynes - aryl dichalcogenides - rongalite - reductive
cleavage