Synthesis of S-alkyl phosphorothioates/phosphorodithioates via ring-opening reaction of sulfonium salts with S8, H-phosphonates or P4S10, and alcohols

The incorporation of phosphorothioate/phosphorodithioate groups into parent molecules has been demonstrated to effectively improve their bioavailability and synthetic application. In this study, we present two types of mild and practical three-component reactions involving cyclic sulfonium salts, S-8/Se, H-phosphonates, or cyclic sulfonium salts, P4S10, and alcohols under transition-metal free conditions. This methodology allows for the synthesis of a diverse range of phosphorothioate/phosphorodithioate-containing compounds (93 examples) in satisfactory yields. Preliminary study suggests that the reaction proceeds through a nucleophilic ring-opening process with high atom efficiency.