Hydrothiolation of Alkynes Using a Solid-Supported Catalyst

Significance

Hydrothiolation of alkynes under solvent-free conditions using a solid-supported catalyst (Al₂O₃/KF) was reported. Thus, propargyl alcohol (1a) and phenylthiol (2a) reacted with Al₂O₃/KF at 60 °C under N₂ atmosphere to give the vinyl sulfide 3a in 63% yield with a Z/E ratio of 86:14 and the regioisomeric 4a in 28% yield (based on the reported regioisomeric ratio). The reaction of 1a and 1-dodecanethiol (2b) gave 3b in 65% yield with Z/E = 55:45 and 4b in 5% yield. The reactions of 1-heptyne (1c) and phenyl­acetylene (1d) with 2a proceeded with perfect regioselectivity to afford the products 3c (52% yield, Z/E = 48:52) and 3d (95% yield, Z/E = 80:20), respectively.