Synthesis of Thioacetal via AgOTf-catalyzed Reaction of 2-Alkynylbenzaldehyde with Thiol

An efficient and mild method for thioacetalization of 2-alkynylbenzaldehydes in the presence of a catalytic amount of silver triflate has been described. This reaction proceeded efficiently to generate 2-alkynylbenzaldehydes thioacetals in good to excellent yields at room temperature within short reaction time (no more than 30 min). This transformation was extremely easy to perform without the need of using anhydrous solvent and inert atmosphere. Chemoselective thioacetalization of benzaldehyde in the presence of acetophenone was also demonstrated.